Medical Coding in History

Medical Coding in History

The Black Death

Medical coding in its earliest form started as an attempt to avoid the Black Death. The bubonic plague, caused by the bacteria Yersinia pestis, arrived in Sicily via ship rats in 1347. It spread rapidly, reaching England in 1348. Almost half the city of London’s population of 70,000 died of the disease over the next 2 years. Given that life expectancy at the time was about 26 years and about 35% of children died before the age of 6, the Black Death contributed to the increased demise of the already death-ridden populace.

Italian author Giovanni Bocaccio lived through the plague in Florence in 1348. In his book The Decameron (1921), he describes how the Black Death got its name:

In men and women alike it first betrayed itself by the emergency of certain tumors in the groin or the armpits, some of which grew as large as a common apple…. The form of the malady began to change, black spots or livid making their appearance in many cases on the arm or the thigh or elsewhere, now few and large, then minute and numerous. These spots were an infallible token of approaching death.

The plague was highly contagious. As soon as people realized that contact with the sick could mean death, they isolated themselves. As Bocaccio describes:

Citizen avoided citizen, how among neighbors was scarce found any that showed fellow-feeling for another, how kinsfolk held aloof and never met. Fathers and mothers were found to abandon their own children, untended, unvisited, to their fate, as if they had been strangers.

Once the initial scourge was over, isolated outbreaks of plague continued in Europe throughout the next 3 centuries. It became an increasingly urban disease due to poor sanitation and crowded living conditions. The Great Plague of 1665 killed 25% of London’s population.  Figure 1-1  illustrates the garb worn by “plague doctors,” who filled the beak area with herbs that were thought to ward off the Black Death.

The London Bills of Mortality, shown in  Figure 1-2 , were published weekly, and as of 1629 included the cause of death. Information was collected by parish clerks in various geographic areas. In order to determine which areas had the most cases of plague, Londoners purchased copies of the Bills and tracked the spread of the disease from one parish to another in order to avoid it. During one week in 1665, when the total number of London deaths was 8,297, bubonic plague accounted for 7,165 of those deaths.

Causes of death found in the Bills include diseases recognized today, such as jaundice, smallpox, rickets, spotted fever, and plague. Other conditions have creative descriptions, such as “griping in the guts,” “rising of the lights” (croup), “teeth,” “king’s evil” (tubercular infection), “bit with a mad dog,” and “fall from the belfry.”

John Graunt, a London merchant, published Reflections on the Weekly Bills of Mortality in 1665. Its central theme was that deaths from plague needed to be examined in the context of all the other causes of mortality in order to understand the effects of all diseases. The 60 disease categories in the Bills constituted the first systematic attempt to analyze the incidence of disease.


FIGURE 1-1 Plague doctor. The beak was filled with herbs thought to ward off the Black Death.

Courtesy of Wellcome Library, London.


FIGURE 1-2 London Bills of Mortality, 1665.

Courtesy of Wellcome Library, London.

It was at this point that the science of epidemiology, the study of epidemics, was born.

During the 18th century, additional classifications were authored by Linnaeus in Sweden (Genera Morborum, 1763), Bossier de Lacroix in France (Nosologia Methodica, 1785), and Cullen in Scotland (Synopsis Nosologic Methodicae, 1785). Nosology is the branch of medicine that deals with classification of diseases.

William Farr and the Cholera Studies

As the first medical statistician for the General Register Office of England, Dr. William Farr revamped the Cullen disease classification to standardize the terminology and utilize primary diseases instead of complications. Farr incorporated additional data into his classification, enabling reporting and analysis of factors such as occupation and its effect on cause of death.

Farr’s dedication to what he called “hygology,” derived from hygiene, was evident in his analysis of the London cholera outbreak of 1849. More than 300 pages of tables, maps, and charts reviewed the possible influence of almost every conceivable death-related factor, including age, sex, rainfall, temperature, and geography. Even day of the week and property value were examined (Eyler, 2001).

The single association consistently present was the inverse relationship between cholera mortality and the elevation of the decedent’s residence above the Thames River. Unfortunately, this led Farr to the erroneous conclusion that the air was more polluted lower by the river, causing the transmission of cholera. He later converted to the correct waterborne germ theory of the disease after conducting a study during a second epidemic in 1866, which included data about the source of drinking water for those who died.

International List of Causes of Death

The need for a uniform classification of causes of death was recognized at the International Statistical Congress convened in Brussels in 1853. The Congress requested that Farr prepare a classification for consideration at its next meeting in Paris in 1855. His classification was based primarily on anatomical site and consisted of 138 rubrics (“History of Development,” n.d.).The list was adopted in 1864 and revised at four subsequent Congresses.

Farr died in 1883, and Jacques Bertillon, the chief statistician of the city of Paris, prepared a revised list that was adopted by the International Statistical Institute in 1893. Known as the Bertillon Classification, it was the first standard system implemented internationally. The American Public Health Association recommended its use in the United States, Canada, and Mexico by 1898. Delegates from 26 countries adopted the Bertillon Classification in 1900, and subsequent revisions occurred through 1920.

Beyond Death

After Bertillon’s death in 1922, interest grew in using the classification to categorize not only causes of mortality, but also causes of morbidity. Morbidity is a diseased state or the incidence of disease in a population. As early as 1928, the Health Organization of the League of Nations published a study defining how the death classification scheme would need to be expanded to accommodate disease tabulation.

Finally, in 1949, at the Sixth Decennial Revision Conference in Paris, the World Health Organization (WHO) approved a comprehensive list for both mortality and morbidity and agreed on international rules for selecting the underlying cause of death. Known as the “Manual of the International Statistical Classification of Diseases, Injuries, and Causes of Death,” it is generally referred to as ICD. From this point forward, the use of ICD was expanded for indexing and retrieval of records and for data concerning the planning and evaluation of health services.

Modern Times

The purpose of the ICD and of WHO sponsorship is to promote international comparability in the collection, classification, processing, and presentation of morbidity and mortality statistics. The United States implemented ICD-1 in 1900 and participated in every revision through ICD-7 until 1968. ICD was used for death classification until the sixth revision, when disease indexing began, and ICD was used for both purposes. With the eighth revision, the United States developed its own version, known as ICDA-8 or ICD-Adapted, due to disagreements over the circulatory section of the international version.

The International Conference for the Ninth Revision was attended by delegations from 46 countries. The classification was being pushed in the direction of more detail by those who wanted to use it for evaluation of medical care or for payment purposes. However, users in less sophisticated areas did not need a high level of detail in order to evaluate their healthcare activities. Steps were taken to ensure the usefulness of the new revision for all users, and the World Health Assembly adopted the ICD-9 revision in May 1976 for implementation effective January 1, 1979. As it did with ICD-8, the United States adopted a clinical modification of the international version, and ICD-9-CM (clinical modification) was used in the United States until October 1, 2015.

ICD-10 was endorsed by the WHO in 1990. Although ICD-10 has been used in the United States since 1999 to classify mortality data from death certificates, ICD-9 has been used for all other purposes, including billing and reimbursement.

ICD-10-CM is the diagnosis classification that will eventually be used in all healthcare settings by all types of providers. It was developed by the National Center for Health Statistics (NCHS) and the Centers for Disease Control and Prevention (CDC) as a clinical modification (CM) of the ICD-10 system used throughout the world. Other countries, such as Canada and Australia, have their own modifications of the international standard code set. The following table summarizes the differences between ICD-9-CM and ICD-10-CM and offers some of the benefits of specificity in the newer system.

ICD-9-CM Diagnosis Codes Versus ICD-10-CM Diagnosis Codes

ICD-9-CM Diagnosis Codes ICD-10-CM Diagnosis Codes
Approximately 14,000 diagnosis codes Approximately 69,000 diagnosis codes
Valid codes have three to five characters Valid codes have three to seven characters
Decimal used after third character Decimal used after third character
First character is alpha (E and V only) or numeric First character is always alpha
Characters two through five are numeric Second character is numeric

Characters three through seven are alpha or numeric

Laterality not addressed Separate codes for laterality (left, right, bilateral) where appropriate
Initial versus subsequent encounters not addressed Separate codes for initial and subsequent encounters in some chapters
Combination codes for commonly associated conditions are limited Many combination codes available
Injuries grouped by type of injury Injuries grouped by anatomic site
Some clinical concepts not represented, such as underdosing, blood alcohol level Additional concepts available

Source:  Modified from ICD-10 Implementation Guide for Large Practices, 2013. Centers for Medicare and Medicaid Services. Available at[1].pdf.

ICD-10-PCS is the classification system that will eventually be used by hospitals to code inpatient procedures. These procedure codes will be used only in the United States. They were developed by 3M under contract with the Centers for Medicare and Medicaid Services (CMS) as a replacement for the outdated ICD-9-CM Procedure Codes. Because ICD-9 procedure codes have only four digits, the system has been severely limited in its ability to accommodate new technology and advances in surgical techniques. ICD-10-PCS is dramatically different in structure and methodology, utilizing the “root operation” concept, which describes the objective of the procedure. Other differences between ICD-9 Procedure Codes and ICD-10-PCS are as follows.

ICD-9-CM Procedure Codes Versus ICD-10-PCS Procedure Codes

ICD-9-CM Procedure Codes ICD-10-PCS Procedure Codes
Approximately 4,000 procedure codes Approximately 72,000 procedure codes
Valid codes have four digits, all numeric Valid codes all have seven alphanumeric characters (the letters O and I are not used, to avoid confusion with 0 and 1)
Decimal used after second digit No decimals used
Procedure codes often contained diagnostic concepts Procedure codes are descriptive of the body system, body part, root operation, approach, device, and certain additional qualifying characters

No diagnostic information is included

Eponymic (named after a person) terms were common No eponyms
Coding process involved finding procedure in the index and verifying it in the tabular lists Coding process is directly from body system/root operation tables Each row in a table defines valid combinations of code values

Source:  Modified from ICD-10 Implementation Guide for Large Practices, 2013. Centers for Medicare and Medicaid Services. Available at[1].pdf.

Reflection of Society

Changes to ICD-9-CM over the years mirrored events in American society. The ICD-9-CM Coordination and Maintenance Committee, a joint effort of the National Center for Health Statistics (NCHS) and the CMS, considered code changes yearly. Although it was possible to code any disease using ICD-9-CM, newly identified or newly concerning conditions often fell into an “other” category, and the assignment of new specific codes was necessary to identify and count those disease entities.

1986 New codes assigned for HIV and AIDS. These were previously coded to the “deficiency of cell-mediated immunity” category. By 1986, over 15,000 deaths due to AIDS-related conditions had occurred in the United States, and the need for codes was evident.
1989 Lyme disease hit the news and was assigned an individual code. Although first observed in the United States in 1977 near Lyme, Connecticut, its identification as a tickborne illness caused growing concern throughout the rest of the country.
1991 Kaposi’s sarcoma was previously coded in the “other malignant neoplasm” category. Its incidence in AIDS patients made the need to separately identify it more important.
1992 As the popularity of contact lenses grew among Americans, so did the problems associated with them. A new code for corneal disease due to contact lenses was implemented.
1992 What do cooking oil in Spain and L-tryptophan in New Mexico have in common? More than 300 people died in Spain in 1981 due to “toxic oil syndrome,” reportedly due to use of contaminated cooking oil. A similar situation occurred in New Mexico in 1989, and on that occasion L-tryptophan was blamed. It was subsequently banned in the United States by the Food and Drug Administration (FDA). Both events involved eosinophilia myalgia syndrome, which got a new code in 1992. The Spanish epidemic is now thought to have been caused by organophosphate poisoning from insecticides (Woffinden, 2001).
1993 A newly understood connection between some types of HPV (human papillomavirus) and cervical cancer resulted in the assignment of a separate code for HPV. Investigators have found evidence of HPV in more than 90% of cervical cancers (CDC, n.d.).
1993 With the increasing use of potent antibiotics and other drugs to combat infection, the crafty bugs have developed resistance to those drugs. A series of codes to identify infection with drug-resistant microorganisms was created.
1995 As “couch potatoes” got fatter, the condition of “morbid obesity” got a separate code to distinguish it from other obesity. Morbid obesity is defined as greater than 125% over normal body weight.
1995 Sensational news reports about a “flesh-eating disease” described the effects of Group A streptococcus manifested as necrotizing fasciitis, a severe soft-tissue infection that can result in gangrene. A new code was assigned.
1996 As more premature infants survived due to better medical care, the incidence of RSV bronchiolitis increased. This was due to the respiratory syncytial virus. A new code was developed for identification purposes.
1996 A sign of the times was the addition of a new code for adult sexual abuse.
1997 Cryptosporidiosis and cyclosporosis got their own codes. These previously rare parasites began showing up more often. An outbreak in Wisconsin where 403,000 people were affected by their drinking water, and additional outbreaks a few years later thought to be caused by imported raspberries, pointed to the need for separate codes.
2002 Although toxic shock syndrome was identified in 1980, it did not receive its own code until 2002. Originally diagnosed in women using high-absorbancy tampons, toxic shock syndrome is now identified in other patients, both male and female, who are infected with Staphylococcus aureus.
2002 Newly arrived in the United States, the mosquito-borne West Nile Virus was assigned its own code.


2002 Codes for the external causes of injury are also part of ICD. A new code was needed to identify injuries from paintball guns.
2002 Codes for coronary atherosclerosis had been around for years, but a new code was implemented to identify coronary atherosclerosis in a transplanted heart.
2002 An entire series of codes was added to classify the external causes of injury and death due to terrorism. Among them were codes for terrorism involving biological weapons and terrorism involving destruction of aircraft, including aircraft used as a weapon.
2003 The evening news showed international air travelers wearing surgical masks. The reason—fear of contracting SARS, severe acute respiratory syndrome. This viral illness appeared in southern China in November 2002. Within 8 months, more than 8,000 people had contracted SARS, with almost 800 dying of the disease. SARS was assigned a new diagnosis code in 2003.
2004 “Dermatitis due to other radiation” was added. It includes tanning beds as radiation sources.
2005 The ever-popular “postnasal drip” got a separate code.
2006 Societal interest in combatting obesity resulted in new codes for pediatric body mass index (BMI) and personal history of bariatric surgery.
2006 A more specific code for altered mental status allowed tracking of this condition that often requires medical care.
2007 Changes in code terminology were needed to reflect current usage. “Sexually transmitted disease” replaced “venereal disease.”
2008 Recognition of environmental causes of illness included exposure to mold, which got its own code.
2009 Quality improvement programs requested and received new codes to categorize operative errors, such as wrong procedure, wrong patient, or wrong body part.
2009 Ongoing U.S. military involvement overseas required implementation of a new code for “family disruption due to family member on military deployment.”
2010 A code added for crack cocaine poisoning.
2011 The last regular, annual updates were made to ICD-9-CM.
2012 The Coordination and Maintenance Committee implemented a partial freeze to both ICD-9-CM and ICD-10-CM/PCS, in effect until October 1, 2015. The purpose of the freeze was to facilitate the planned implementation of ICD-10 in 2014, without the need to deal with major last-minute changes.
2013 Limited updates were allowed to capture new technologies and diseases.
2014 On March 27, 2014, the U.S. House of Representatives passed by voice vote H.R. 4302, a bill “to amend the Social Security Act to extend Medicare payments to physicians and other provisions of the Medicare and Medicaid programs, and for other purposes.” The intent of this bill was to “patch” the sustainable growth rate (SGR) formula for physician payment that was set to expire on March 31, 2014. The U.S. Senate passed the bill on March 31 and it was signed into law by the president on April 1, 2014. The bill contained a clause prohibiting the Secretary of Health and Human Services from requiring implementation of ICD-10-CM and ICD-10-PCS until October 1, 2015. This additional delay will give unprepared providers more time to ready their practices for ICD-10.

Preparation for Coding Success

Because of the greatly increased level of detail in ICD-10-CM and ICD-10-PCS, it is even more important that individuals involved in coding and billing be prepared to use the new systems correctly. In addition to studying medical terminology, anatomy and physiology, and disease processes, exposure to real or sample provider documentation is very important. Being able to read a discharge summary or an operative report and visualize what was done is key to assigning correct codes.


Bocaccio, G. (1921). The decameron. (J. M. Rigg, Trans.). London: The Navarre Society. (Original work published in 1348–1353)

Centers for Disease Control and Prevention. (n.d.). HPV-associated cancers statistics. Retrieved December 10, 2013, from

Eyler, J. M. (2001). The changing assessments of John Snow’s and William Farr’s cholera studies. Soz.-PrŠventivmed, 46, 225–232. Retrieved December 11, 2013, from

History of the development of the ICD. (n.d.). Retrieved December 10, 2013, from

Woffinden, B. (2001, August 25). Cover-up. The Guardian. Retrieved December 10, 2013, from








Diagnosis Coding: A Number for Every Disease

What Is a Diagnosis?

A diagnosis is the identification of a disease from its symptoms. Obviously, the next question is, “What is a symptom?” You are the best judge of that, because a symptom is a perceptible change in your body or its functions that can indicate disease. Although it is possible to be sick or have a disease and have no symptoms, a symptom is a hint that there may be a problem and that you should seek professional help.

When you have a sore throat, that is a symptom. If the sore throat lasts more than a day or two, you will probably visit your doctor to get his or her opinion about the cause of the sore throat. Based on your symptom, the sore throat, and an exam of your physical condition, the doctor may arrive at a diagnosis. More than 100 diagnoses could possibly be the cause of your sore throat. How will the doctor arrive at the correct diagnosis?

Deducing the Diagnosis: History

The first step in the path toward a diagnosis is the history. The doctor may ask you questions such as the following:

img How long have you had the sore throat? (duration)

img What part of your throat hurts? (location)

img Is the pain continuous? Does it become better or worse? (timing)

img How does it compare to other sore throats you have had? (severity)

img Do you also have other symptoms? (associated signs and symptoms)

img What are you doing when it hurts? (context)

img How would you describe the pain? (quality)

img What have you done to obtain relief? Did it work? (modifying factors)

These eight categories of questions are known as the History of Present Illness (HPI). They constitute a chronological description of your present illness from the first sign or symptom to the present. Once you have responded to these questions, the direction to go next will usually be clearer to the doctor.

Review of Systems (ROS) is an inventory of body systems obtained through a series of questions that seek to identify signs and/or symptoms that you may be experiencing ( Figure 2-1 ). Your doctor may give you a check-off form to fill out in order to get your responses to these questions.

There are 14 systems that the doctor may review:

Constitutional Weight, temperature, fatigue, sleep habits, eating habits
Eyes Vision, use of glasses, pain, blurry vision, halos, redness, tearing, itching
Ears, Nose, Mouth, Throat Pain, hearing loss, infections, nose bleeds, ringing in ears, runny nose, colds, toothaches, sore throat, sores
Cardiovascular Chest pain, shortness of breath on exertion, murmurs, palpitations, varicose veins, edema, hypertension
Respiratory Cough, wheezing, bronchitis, color of sputum, spitting up blood
Gastrointestinal Stomach pain, heartburn, nausea, vomiting, bloating, bowel movements, hemorrhoids, indigestion
Genitourinary Blood in urine, incontinence, pain on urination, urgency, frequency, urinating at night, dribbling Female: menstrual history, sexual history, infections, Pap smears, menopause Male: hernias, sexual history, pain, discharge, infections
Musculoskeletal Joint pain, swelling, redness, limited range of motion, stiffness, deformity
Skin/Breast Lesions, lumps, sores, bruising, itching, dryness, moles
Neurological Dizziness, fainting, seizures, falls, numbness, pain, abnormal sensation, vertigo, tremor
Psychiatric Depression, anxiety, memory loss, sleep problems, nervousness
Endocrine Hot or cold intolerance, goiter, protruding eyeballs, diabetes, hair distribution, increasing thirst, thyroid disorders
Hematologic/Lymphatic Allergy/Immune Anemia, bruising, enlarged lymph nodes, transfusion history Hay fever, drug or food allergies, sinus problems, HIV status, occupational exposure


FIGURE 2-1 “Review of symptoms” form your doctor may ask you to complete.

The doctor may perform all or part of the review of systems, depending on your presenting problem. The review of systems is intended to identify symptoms you may have forgotten to mention. It also explores and provides support for the doctor’s theory about the cause of your symptom. If he feels that the sore throat is due to a respiratory allergy, you can expect to see the respiratory and allergy portions emphasized in the review of systems.

Because hereditary or environmental factors contribute to many diseases, the final part of the history performed by the doctor is the past, family, and social history.

Past history includes illnesses, surgeries, medications, and allergic reactions. A thorough documentation of past history should include checking by the physician for objective evidence that the reported conditions actually existed. Lab results and diagnostic testing reports in your medical record should support the history.

Family history covers any factor within your immediate family that may affect you or the probability that you will have specific conditions, such as cancer, diabetes, heart disease, or other hereditary risk factors. The presence of communicable diseases that are not hereditary can also be important if you are exposed through contact with your family.

Social history encompasses a wide variety of habits, including the following:

img Smoking history: How much, how long

img Alcohol intake: Type, quantity, frequency

img Other drug use: Type, route, frequency, duration

img Sexual activity: Gender orientation, birth control, marital status, risk factors

img Work history: Occupation, risk factors

img Hobbies, activities, interests

The information in the social history not only provides additional information relevant to determining the cause of the presenting symptoms but also can facilitate the physician–patient relationship if your doctor knows more about you as a person and not just as a body.

Deducing the Diagnosis: Exam

According to the federal government’s Center for Medicare and Medicaid Services (CMS), your doctor can perform 12 different types of physical examinations. Unless you are seeing a specialist, your doctor will usually perform a “general multisystem examination,” including the systems he or she feels are relevant to your presenting problem or symptom.

The following are a few definitions of terms used in describing physical exam procedures:

img Palpation: Examination by pressing on the surface of the body to feel the organs or tissues underneath.

img Auscultation: Listening to sounds within the body, either by direct application of the ear or through a stethoscope.

img Percussion: A method of examination by tapping the fingers at various points on the body to determine the position and size of structures beneath the surface.

The officially defined “general multisystem examination” includes the following (Center for Medicare and Medicaid Services, n.d.) categories.


img Measurement of any three of the following seven vital signs:

img Sitting or standing blood pressure

img Supine blood pressure

img Pulse rate and regularity

img Respiration

img Temperature

img Height

img Weight

img General appearance of the patient (e.g., development, nutrition, body habits, deformities, attention to grooming)


img Inspection of conjunctivae and lids

img Examination of pupils and irises (e.g., reaction to light and accommodation, size and symmetry)

img Ophthalmoscopic examination of optic discs (e.g., size, C/D ratio, appearance) and posterior segments (e.g., vessel changes, exudates, hemorrhages)


img External inspection of ears and nose (e.g., overall appearance, scars, lesions, masses)

img Otoscopic examination of external auditory canals and tympanic membranes

img Assessment of hearing (e.g., whispered voice, finger rub, tuning fork)

img Inspection of nasal mucosa, septum, and turbinates

img Inspection of lips, teeth, and gums

img Examination of oropharynx: oral mucosa, salivary glands, hard and soft palates, tongue, tonsils, and posterior pharynx


img Examination of neck (e.g., masses, overall appearance, symmetry, tracheal position, crepitus)

img Examination of thyroid (e.g., enlargement, tenderness, mass)


img Assessment of respiratory effort (e.g., intercostals retractions, use of accessory muscles, diaphragmatic movement)

img Percussion of chest (e.g., dullness, flatness, hyperresonance)

img Palpation of chest (e.g., tactile fremitus)

img Auscultation of lungs (e.g., breath sounds, adventitious sounds, rubs)


img Palpation of heart (e.g., location, size, thrills)

img Auscultation of heart with notation of abnormal sounds and murmurs

img Examination of

img Carotid arteries (e.g., pulse amplitude, bruits)

img Abdominal aorta (e.g., size, bruits)

img Femoral arteries (e.g., pulse amplitude, bruits)

img Pedal pulses (e.g., pulse amplitude)

img Extremities for edema and/or varicosities


img Inspection of breasts (e.g., symmetry, nipple discharge)

img Palpation of breasts and axillae (e.g., masses or lumps, tenderness)


img Examination of abdomen with notation of presence of masses or tenderness

img Examination of liver and spleen

img Examination for presence or absence of hernia

img Examination (when indicated) of anus, perineum, and rectum, including sphincter tone, presence of hemorrhoids, rectal masses

img Obtain stool sample for occult blood test when indicated



img Examination of the scrotal contents (e.g., hydrocele, spermatocele, tenderness of cord, testicular mass)

img Examination of the penis

img Digital rectal examination of prostate gland (e.g., size, symmetry, nodularity, tenderness)


Pelvic examination (with or without specimen collection for smears and cultures) including:

img Examination of external genitalia (e.g., general appearance, hair distribution, lesions) and vagina (e.g., general appearance, estrogen effect, discharge, lesions, pelvic support, cystocele, rectocele)

img Examination of urethra (e.g., masses, tenderness, scarring)

img Examination of bladder (e.g., fullness, masses, tenderness)

img Examination of the cervix (e.g., general appearance, lesions, discharge)

img Examination of the uterus (e.g., size, contour, position, mobility, tenderness, consistency, descent, or support)

img Examination of the adnexa/parametria (e.g., masses, tenderness, organomegaly, nodularity)


Palpation of lymph nodes in two or more areas:

img Neck

img Axillae

img Groin

img Other


img Examination of gait and station

img Inspection and/or palpation of digits and nails (e.g., clubbing, cyanosis, inflammatory conditions, petechiae, ischemia, infections, nodes)

img Examination of joints, bones, and muscles of one or more of the following six areas: (1) head and neck; (2) spine, ribs, and pelvis; (3) right upper extremity; (4) left upper extremity; (5) right lower extremity; and (6) left lower extremity. The examination of a given area includes:

img Inspection and/or palpation with notation of presence of any misalignment, asymmetry, crepitation, defects, tenderness, masses, effusions

img Assessment of range of motion with notation of any pain, crepitation, or contracture

img Assessment of stability with notation of any dislocation (luxation), subluxation, or laxity

img Assessment of muscle strength and tone (e.g., flaccid, cogwheel, spastic, with notation of any atrophy or abnormal movements


img Inspection of skin and subcutaneous tissue (e.g., rashes, lesions, ulcers)

img Palpation of skin and subcutaneous tissue (e.g., induration, subcutaneous nodules, tightening)


img Test cranial nerves with notation of any deficit

img Examination of deep tendon reflexes with notation of any pathological reflexes (e.g., Babinski)

img Examination of sensation (e.g., by touch, pin vibration, proprioception)


img Description of patient’s judgment and insight

img Brief assessment of mental status, including:

img Orientation to time, place, and person

img Recent and remote memory

img Mood and affect (e.g., depression, anxiety, agitation)

Reality Check

You are thinking, “My doctor spent 15 minutes with me and didn’t do half of this stuff!” You are correct. The extent of the examination will depend on what your doctor needs to examine or measure in order to identify the cause of your sore throat. A likely scenario would be taking your vital signs (done by the nurse), examining your throat, looking at your ears to see if your tympanic membranes are involved, listening to your chest, and possibly palpating your lymph nodes. The doctor will also observe your general appearance for additional signs.

Some of the information obtained during the physical exam is noted solely by observation. The doctor can tell just by looking whether you have a rash that might indicate a disease related to a sore throat. Likewise, your ability to walk across the room and climb up on the exam table will provide clues to your gait. The discussion between you and your doctor will yield information about your judgment and insight into your mental status.

Deducing the Diagnosis: Medical Decision Making

Now that your doctor knows the history of your sore throat and has examined you, the next step in the process of arriving at a diagnosis is medical decision making. This involves assessment of the objective data and selection of the most likely cause of your sore throat. It may involve additional diagnostic testing, such as a throat culture to check for bacteria. If you are a smoker or if it is goldenrod season, the doctor may suspect other causes.

In complicated cases with many presenting symptoms, the doctor may use the process of differential diagnosis, which is weighing the probability of one disease versus another as the cause of the patient’s symptoms. Sore throat can be caused by bacterial or viral infection, throat irritation or inflammation, allergic reaction, fungal infection, or even just dry air.

Your doctor will make a decision about why your throat is sore and provide a treatment plan that may involve prescription or over-the-counter medications; symptomatic treatments, such as gargles; or environmental changes, such as a humidifier.

Documenting the Diagnosis

Once the decision-making process is complete, the doctor must document the diagnosis in your medical record. A complete diagnostic statement always includes the following:

img Site: The physical location; if the location has laterality (left or right), it must be documented as well.

img Etiology: The cause of the condition.

For your sore throat, a complete diagnostic statement might be the following:

img “Strep pharyngitis”

img Site = pharynx

img Etiology = streptococcal bacteria

What Number Is My Diagnosis?

Now that you have a diagnosis documented in words by your doctor, it can be converted into a diagnosis code number. The International Classification of Diseases, Revision 10, Clinical Modification (ICD-10-CM) will be used in the United States for diagnosis coding as of 2015. It contains over 71,000 unique codes. This does not mean that each of the more than 100,000 known disease entities has a separate code. When the phrase “diagnosis code” is used, its actual meaning is “diagnosis category code.”

An example of a diagnosis category is R79.0, “Abnormal level of blood mineral.” This code category includes abnormal blood levels of cobalt, copper, iron, magnesium, or zinc. Use of R79.0 does not tell you which mineral is abnormal. Nor does it tell you whether the blood level is abnormally low or abnormally high.

A diagnosis code category is analogous to a zip code. The zip code 04558 is for Maine, but it covers two towns, New Harbor and Pemaquid. With just the zip code number, it is not possible to positively identify which town is intended.

The translation process known as coding takes the words documented as a diagnosis and converts them into a diagnosis category code number. This is necessary not only for statistical purposes, but also because of the variation in the naming conventions for diseases. Regional differences in medical terminology in the United States may result in several different terms for the same disease entity.

Your sore throat diagnosis, “strep pharyngitis,” is assigned to a category code number by a two-step process.

1. The main term or noun, “pharyngitis,” is located in the alphabetical part of ICD-10-CM, the index to diseases; the subterm or adjective “strep” is searched for under “pharyngitis” ( Figure 2-2 ).

2. A category code number, J02.0, is listed next to the entry for “Pharyngitis, streptococcal.” In order to ensure that this number is correct, it is necessary to verify the number in the numerical part of ICD-10-CM, known as the tabular list ( Figure 2-3 ).

The diagnostic terms listed under J02.0 include not only streptococcal pharyngitis, but also septic pharyngitis and streptococcal sore throat. Previously, in ICD-9-CM, the code for strep pharyngitis also included strep laryngitis and strep tonsillitis. These have their own codes in ICD-10-CM, an example of its higher specificity.


FIGURE 2-2 Pharyngitis index entries.

Reproduced from ICD-10-CM Code Index to Diseases and Injuries, 2014. Centers for Medicare and Medicaid Services. Available at


FIGURE 2-3 Pharyngitis tabular entries.

Reproduced from ICD-10-CM Tabular List of Diseases and Injuries, 2014. Centers for Medicare and Medicaid Services. Available at

How Hard Can This Be?

The two-step coding process just described sounds straightforward: look in the alphabetical index and then verify the number in the tabular list. Why can’t this be done by a computer? In fact, most hospitals and other medical facilities do use computerized coding tools called encoders to facilitate the coding process. They range from simple programs that are only replications of the coding books in a computerized format to sophisticated interactive software that asks all of the questions necessary to arrive at the correct diagnosis category code.

For your sore throat diagnosis, the simple encoder would bring up the list of pharyngitis entries, and the coding analyst would have to select “streptococcal” from that list. The sophisticated encoder would find pharyngitis and then ask the user the questions “Due to bacteria?” and then “Due to which bacteria?” before selecting a code. Branching logic in the sophisticated products ensures correct code selection in complex disease entities.

Why can’t the computer do it all? The coding process is subject to any number of potential problems that make it essential that a coding analyst, a knowledgeable human being, be involved. Because diagnosis codes are often used to determine reimbursement, the coding process is governed by rules that must be followed by any entity submitting a claim for payment by a third party such as a government program or private insurance.

Failure to follow these rules can result in the submission of a false claim, which is subject to criminal and civil penalties, including imprisonment and fines.

What can go wrong in the diagnosis coding process?

img Illegible physician handwriting

img Look at  Figure 2-4 . What do you think it says?


FIGURE 2-4 Illegible handwriting.

img Illogical physician diagnosis documentation

img “#1) Chest pain secondary to #1”

img “Fractured ear lobe” (not anatomically possible)

img Lack of physician documentation

img Transcription errors by typist or voice-recognition systems

img “Baloney amputation” (should be below-knee amputation)

img “Liver birth” (should be live birth)

img Content of the rest of the patient’s medical record does not support the diagnosis documented

img Lack of specificity

img “Anemia” (there are several hundred different types of anemia)

Each of these issues must be resolved before an accurate diagnosis code can be assigned.

What Are the Rules?

The rules for diagnosis coding in the United States are developed and approved by the Cooperating Parties for ICD-10-CM, which include the CMS, the National Center for Health Statistics (NCHS), the American Hospital Association (AHA), and the American Health Information Management Association (AHIMA). Both ICD-10-CM and the Official Guidelines for Coding and Reporting are in the public domain and may be accessed at no charge on the Internet or via public document depository library services (National Center for Health Statistics, 2014).

The rules are 117 pages and consist of the following:

img Conventions and general coding guidelines

img Chapter-specific guidelines

img Selection of principal diagnosis for inpatients

img Reporting additional diagnoses for inpatients

img Diagnostic coding and reporting guidelines for outpatient services

img Present-on-admission reporting guidelines

In addition to the official rules, federal and state government programs such as Medicare and Medicaid promulgate regulations intended to define appropriate code usage or add the weight of law to the guidelines. An example was the Medicare transmittal that defined for its contractors the appropriate rules for ICD-9-CM coding for diagnostic tests (Department of Health and Human Services, 2001). This transmittal was initially issued because of concerns about contractors in different geographic locations inconsistently interpreting the official guidelines. The transmittal language was later incorporated into the official claims processing manual.

Conventions: Section I.A.


img Brackets [ ] are used in the tabular list to enclose synonyms, alternative wording, or explanatory phrases.

img Parentheses ( ) are used to enclose supplementary words that may be either present or absent in the statement of a disease without affecting the code number to which it is assigned. For example, see the following index entry:

Hallucinosis (chronic) F28

It makes no difference whether the word chronic is present in the diagnosis.

img Colons (:) are used in the tabular list after an incomplete term that needs one or more of the words following the colon to make it assignable to a specific category.


img NEC means “not elsewhere classifiable.” This is equivalent to “other specified,” which means the documentation in the medical record provides detail for which a specific code does not exist.

img NOS means “not otherwise specified.” This is equivalent to “unspecified,” indicating that the documentation in the medical record is insufficient to assign a more specific code.

Standard meanings:

img “And” should be interpreted to mean either “and” or “or.”

img “With” should be interpreted to mean “associated with” or “due to.”

Instructional Notes: Section I.A.

img “See” following a main term in the alphabetic index means that another term should be referenced. The correct code will not be located unless this instruction is followed.

img “See also” means that there is another main term that may have useful additional index entries that are helpful, but it is not mandatory to follow the “see also” instruction if the necessary code is found under the original main term.

img “Code first” mandates that the underlying etiology or cause of the condition to be coded must be coded first, and then the manifestation.

img “Use additional code” will be found at the etiology listing to remind coders that the manifestation should also be coded.

img “Code also” means that two codes may be needed to fully describe a condition, but the sequence of those codes is not defined.

img “Excludes type 1” is used when two conditions cannot occur together and should not be coded together.

img “Excludes type 2” means the excluded condition is not part of the condition represented by the code, but the two codes may be used together, if appropriate.

General Coding Guidelines: Section I.A.

These guidelines tell coding analysts the basic information they need in order to code correctly, based on physician documentation.

img Locate each term in the alphabetic index and verify the code selected in the tabular list. The alphabetic index does not always provide the full code, so it is mandatory to reference the tabular list as well. Read and be guided by any instructional notations.

img Valid diagnosis codes may have three, four, five, six, or seven characters. Any code with more than three characters has a decimal point after the third character. A code with fewer than seven characters may only be used if it is not further subdivided.

Example: “J14 Hemophilus pneumonia” may be used because it is not further subdivided. “J15 Bacterial pneumonia, NEC” may not be used with only three characters, because it is further subdivided into several four-character codes.

ICD-10-CM uses a placeholder, character “X,” at certain codes to allow for future expansion. The “X” placeholder may also be needed if a code that requires a seventh character is not a six-character code; the X must be used to fill in the empty characters.

img Codes that describe symptoms and signs, as opposed to diagnoses, are acceptable if a related definitive diagnosis has not been established by the physician.

Example: R55, syncope (fainting), is a symptom code. It may be used if the physician does not identify and document a diagnosis responsible for the fainting.

img Signs and symptoms that are an integral part of a disease process should not be assigned as additional codes.

Example: Shortness of breath is integral to congestive heart failure and would not be coded separately.

img Signs and symptoms that may not be associated routinely with a disease process should be coded when present.

img Some single conditions may require more than one code for a full description. Generally, one code is for the etiology and the other is for the manifestation of the disease. Additional situations requiring more than one code are related to sequelae, complications, and obstetrical cases.

img When a condition is described as both acute and chronic, code both and sequence the acute code first.

Example: Acute sinusitis is J01.90. Chronic sinusitis is J32.9. Both codes would be used for a diagnostic statement of “Acute and chronic sinusitis.”

img Combination codes are single codes used for a combination of two diagnoses, or a diagnosis with an associated manifestation or complication. Do not use multiple codes if a combination code describes all of the elements.

Example: Acute cholecystitis is K81.0. Chronic cholecystitis is K81.1. Acute cholecystitis with chronic cholecystitis is K81.2. Only K81.2 would be used to describe both.

img A sequela, or late effect, is the residual effect after the acute phase of an illness or injury has terminated. There is no time limit as to when a sequela code can be used. The condition or nature of the sequela is coded first, and the sequela code second.

What Is the Structure of the Diagnosis Codes?

How is the diagnosis system set up to handle the thousands of coding categories in a logical fashion? The 21 chapters in the Classification of Diseases and Injuries are divided along two major schemes:

1. Anatomic system chapters, such as “Diseases of the Digestive System”

2. Disease or condition categories, such as the “Neoplasms” chapter, where all neoplasms are found, regardless of anatomic location

Chapter Title Code Range
  1. Certain Infectious and Parasitic Diseases A00–B99
  2. Neoplasms C00–D49
  3. Diseases of the Blood and Blood-Forming Organs and Certain Disorders Involving the Immune Mechanism D50–D89
  4. Endocrine, Nutritional, and Metabolic Diseases E00–E89
  5. Mental, Behavioral, and Neurodevelopmental Disorders F01–F99
  6. Diseases of the Nervous System G00–G99
  7. Diseases of the Eye and Adnexa H00–H59
  8. Diseases of the Ear and Mastoid Process H60–H95
  9. Diseases of the Circulatory System I00–I99
10. Diseases of the Respiratory System J00–J99
11. Diseases of the Digestive System K00–K95
12. Diseases of the Skin and Subcutaneous Tissue L00–L99
13. Diseases of the Musculoskeletal System and Connective Tissue M00–M99
14. Diseases of the Genitourinary System N00–N99
15. Pregnancy, Childbirth, and the Puerperium O00–O9A
16. Certain Conditions Originating in the Perinatal Period P00–P96
17. Congenital Malformations, Deformations, and Chromosomal Abnormalities Q00–Q99
18. Symptoms, Signs, and Abnormal Clinical and Laboratory Findings, Not Elsewhere Classified R00–R99
19. Injury, Poisoning, and Certain Other Consequences of External Causes S00–T88
20. External Causes of Morbidity V00–Y99
21. Factors Influencing Health Status and Contact with Health Services Z00–Z99

Within each ICD-10-CM chapter and section, there are categories that are arranged in a mostly logical fashion, either by body site or by the cause or etiology. Subcategories are arranged the same way, with a fourth character of “8” generally used to indicate some “other” specified condition, and the fourth character “9” usually reserved for unspecified conditions.

Which Diagnosis Is Listed First?

The sequencing of diagnosis codes is intimately linked to reimbursement, and thus is also defined by official rules.


The Uniform Hospital Discharge Data Set, or UHDDS, applies to diagnosis sequencing for all non-outpatient settings (inpatient, short-term care, acute care, psychiatric, and long-term care hospitals; home health agencies; rehab facilities; and nursing homes). It has been in use since 1985 and defines the principal diagnosis as “that condition established after study to be chiefly responsible for occasioning the admission of the patient to the hospital for care” (“1984 Revision,” 1985). According to this definition, if you are admitted to the hospital because of chest pain but fall out of bed and break your hip, the chest pain will still be your principal diagnosis, even if you end up staying an extra 2 weeks to have your hip repaired.

The sequencing rules for inpatients are found in Sections II and III.

img Do not use a symptom or sign as the principal diagnosis if a definitive diagnosis has been established.

img If there are two or more interrelated conditions that could each meet the definition of principal diagnosis, either may be sequenced first.

img Comparative/contrasting conditions documented as “either/or” are sequenced according to the circumstances of the admission.

img If a symptom is followed by comparative/contrasting conditions, all are coded, with the symptom first. However, if the symptom is integral to the conditions listed, no code for the symptom is reported.

img Even if the original treatment plan is not carried out, follow the definition for principal diagnosis.

img If admission is for treatment of a complication, the complication code is sequenced first.

img If a patient is admitted for inpatient care after outpatient surgery at the same hospital, and if the reason for admission is a complication, that code would be sequenced first. If the admission is for another condition unrelated to the surgery, the unrelated condition goes first. If no complication or other condition is documented as responsible for the admission, use the reason for the outpatient surgery as the principal diagnosis.

img When the admission is for rehab, use the condition for which the service is being performed as the principal diagnosis. If that condition is no longer present, such as in a patient who is being admitted after a hip replacement, use the appropriate aftercare code as the principal diagnosis.

img If the diagnosis is documented as “probable,” “suspected,” “likely,” “questionable,” “possible,” or “rule out,” the condition is coded as if it existed. Note that this rule varies significantly from that for outpatients (see the following section).


Because the UHDDS does not apply to outpatients, the selection of the first diagnosis is governed by the ICD-10-CM official guidelines. The first-listed diagnosis is defined as “the diagnosis, condition, problem, or other reason for encounter/visit shown in the medical record to be chiefly responsible for the services provided” (National Center for Health Statistics, 2014). Additional rules for outpatient sequencing are as follows:

img Do not code diagnoses documented as “probable,” “suspected,” “questionable,” “rule out,” or “working diagnosis.” Rather, code the condition to the highest degree of certainty for that encounter/visit, such as signs, symptoms, abnormal test results, or other reason for the visit. Note that this rule for outpatient sequencing differs significantly from that noted previously for inpatients.

img For patients receiving diagnostic services only, sequence first the diagnosis, condition, problem, or other reason shown to be responsible for the service. For encounters for routine laboratory/radiology testing in the absence of any signs, symptoms, or associated diagnoses, assign code Z01.89. If routine testing is performed during the same encounter as a test to evaluate a sign, symptom, or diagnosis, it is appropriate to assign both the Z code and the code describing the reason for the nonroutine test. For outpatient encounters for diagnostic tests that have been interpreted by a physician and the final report is available at the time of coding, code any confirmed or definitive diagnoses documented in the interpretation.

img For patients receiving therapeutic services only, code first the diagnosis responsible for the service. An exception to this rule occurs if the encounter is for chemotherapy or radiation therapy, in which case the Z code for the service is listed first and the diagnosis second.

img For pre-op exams, use the appropriate Z code, followed by the condition necessitating the surgery and any findings related to the pre-op evaluation.

img For ambulatory surgery, use the diagnosis for which the surgery was performed. If the post-op diagnosis differs from the pre-op, select the post-op for coding.

img For routine prenatal visits when no complications are present, use the Z34 code for supervision of pregnancy. If the pregnancy is high-risk, a code from category O09 should be used.

img Encounters for general medical examinations should be coded according to whether abnormal findings resulted; a code for the finding should be used as an additional diagnosis.

What’s in Each Diagnosis Chapter?

As each ICD-10-CM diagnosis chapter is discussed, any applicable coding rules from the official guidelines will be included.


The diseases in this chapter are those considered to be communicable, either from human to human or from another host, such as a mosquito, to humans. Parasites are organisms that live in or feed on humans, such as worms. This chapter is the realm of public health departments across the nation that monitor and try to prevent outbreaks of communicable diseases.

The structure of this chapter is based primarily on the organism causing the condition to be coded, but it can also be grouped according to the primary body system affected. An example is the intestinal infectious diseases section (A00–A09), which includes cholera, typhoid, salmonella, shigellosis, food poisoning, and other intestinal infections. As new organisms are identified and new outbreaks of infectious diseases occur, additional codes are added to this chapter. Some of the conditions in this chapter represent diseases thought to be eradicated, such as smallpox. The last known case was in 1977. However, small quantities of the virus exist in research laboratories, and the potential for accidental exposure is still present, so it is necessary to retain the code for possible future use. For some conditions, vaccines have been developed for prevention but the diseases continue to occur in other age groups where many individuals have not been vaccinated. An example is whooping cough in adults.

In some coding categories, lots of detailed codes are available but the usual medical record documentation is too scanty to allow their use. An example from this chapter is tuberculosis. In ICD-9-CM, fifth-digit code assignment was based on the method by which the mycobacterium infection was confirmed (i.e., microscopy, bacterial culture, histological examination). This information was almost never readily available; in ICD-10-CM the classification of tuberculosis is based solely on the organs involved.

Specific official coding guidelines for conditions in this chapter include the following:

HIV (Human Immunodeficiency Virus Infections)

Seven code categories are available to describe HIV situations:

B20 HIV disease (includes AIDS)
O98.7_ HIV disease complicating pregnancy, childbirth, and the puerperium
Z21 Asymptomatic HIV infection status
R75 Inconclusive laboratory evidence of HIV
Z20.6 Exposure to HIV
Z11.4 Encounter for HIV screening
Z71.7 HIV counseling

The physician’s diagnostic statement that the patient is HIV positive or has an HIV-related illness is sufficient to code. Current documentation of positive serology or culture is not required.

HIV (Human Immunodeficiency Virus Infections)

Reason for Encounter Use Codes
Treatment of HIV-related condition, AIDS B20 plus additional codes for HIV-related conditions
Treatment of unrelated condition, such as an injury Code for unrelated condition plus B20, plus codes for HIV-related conditions
Patient is “HIV-positive” without symptoms Z21
Inconclusive HIV serology, no definitive diagnosis and no manifestations R75
Previously diagnosed HIV-related illness; once the patient has developed an HIV-related illness, he or she should always be assigned to B20, never R75 or Z21 B20
HIV infection in pregnancy Note: Codes from Chapter 15 always take sequencing priority O98.7_ plus B20, plus codes for HIV-related conditions
Asymptomatic HIV during pregnancy O98.7_ plus Z21
HIV testing Z11.4
Receive results of HIV testing if results are negative Note: If results are positive, see previous guidelines above Z71.7

Source:  Data from International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM), 2014. Centers for Medicare and Medicaid Services and the National Center for Health Statistics. Available at

Sepsis, Severe Sepsis, and Septic Shock

Sepsis is an illness in which the body has a severe response to bacteria or other germs. This response may be called systemic inflammatory response syndrome (SIRS). Septic shock refers to circulatory failure associated with severe sepsis.

Sepsis, Severe Sepsis, and Septic Shock

Reason for Encounter Use Code
Urosepsis This is a nonspecific term with no default code. The provider must be queried for clarification if this term is used.
Bacteremia/septicemia (bacteria in blood) without documented sepsis diagnosis Use R78.81.
Sepsis Code for underlying systemic infection, or A41.9 if organism not specified.
Severe sepsis (sepsis with organ dysfunction) Code for underlying systemic infection plus a code from R65.2_ denoting severe sepsis, plus codes for the associated acute organ dysfunctions.
Septic shock (severe sepsis with circulatory failure) Code for systemic infection plus R65.21, plus codes for other acute organ dysfunctions.
Sepsis or septic shock due to a postprocedural infection T81.4, infection following a procedure or O86.0, infection of obstetrical surgical wound, is coded first, plus the code for the specific infection and any acute organ dysfunctions.

Source:  Data from International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM), 2014. Centers for Medicare and Medicaid Services and the National Center for Health Statistics. Available at

Infections Resistant to Antibiotics

Related to the infectious disease codes are the Z16 codes for infection with antimicrobial-resistant organisms, which would be used as additional codes secondary to the infection code. In some cases, the infection codes themselves include resistance, such as A41.02, infection due to methicillin-resistant Staphylococcus aureus (MRSA), in which case a Z16 code would not be used.


The word neoplasm means “new growth.” From a coding perspective, there are four types of neoplasms:

img Malignant: In common usage, the term cancer is used to describe a malignant neoplasm. These new growths are usually invasive, spreading to the lymph system and to distant sites in the body (metastases).

img Primary: Malignant neoplasm in the site where it originated

img Secondary: Malignant neoplasm in the site it has metastasized to, or spread to

img In situ: Carcinoma cells that are still confined to the original site and are undergoing malignant changes

img Benign: Although benign neoplasms do not spread to other sites, their growth may cause problems due to size, putting extra pressure on nearby structures. Some benign neoplasms, such as adenomatous polyps of the colon, are classified as benign but are considered “precancerous,” requiring ongoing monitoring.

img Uncertain behavior: For some tumors, a decision cannot be made about whether they are benign or malignant, even upon pathology examination.

img Unspecified nature: This category is for neoplasm documentation that is not specific enough to determine the behavior.

Specific official coding guidelines for conditions in this chapter include the following.


Reason for Encounter Use Code
Treatment of the primary malignancy (not chemo or radiation) Code for malignant neoplasm of primary site
Treatment of a secondary (metastatic) site only Code for malignant neoplasm of secondary site
Treatment of anemia associated with malignancy Code for malignancy plus code for anemia
Treatment of anemia associated with chemotherapy, immunotherapy, or radiation therapy Code for anemia plus code for neoplasm, plus code for the adverse effect
Treatment of dehydration due to malignancy or therapy Code for dehydration plus code for malignancy
Treatment of complication of surgery Code for complication
Treatment of pathological fracture due to neoplasm Code for fracture plus code for neoplasm
Chemotherapy Z51.11 plus code for malignancy
Radiation therapy Z51.0 plus code for malignancy
Immunotherapy Z51.12 plus code for malignancy
Cancer in a pregnant patient Code from O9A.1_ malignant neoplasm complicating pregnancy, childbirth, or the puerperium, plus code for malignancy

Source:  Data from International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM), 2014. Centers for Medicare and Medicaid Services and the National Center for Health Statistics. Available at

Care must be taken when the term metastatic is used. It can mean either a primary neoplasm that is spreading, such as a laryngeal tumor that has spread to a cervical lymph node, or it can be documented by the physician to refer to the metastatic site, such as “metastatic cancer, lymph node.”

In assigning neoplasm codes, it is essential that the search begin by looking for the morphologic type (name such as carcinoma, glioma, or leiomyoma). This is necessary in order to learn whether the neoplasm is malignant, benign, or other. Once this information is in hand, the search moves to the anatomic site. ICD-10-CM, like its predecessor, contains a Neoplasm Table arranged alphabetically by anatomic site.

Neoplasm Table Sample


Source:  Data from International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM), 2014. Centers for Medicare and Medicaid Services and the National Center for Health Statistics. Available at

The guidelines include several rules about coding based on the extent of involvement of the neoplasm:

img A primary malignant neoplasm that overlaps two or more contiguous sites should be classified to the subcategory .8 (overlapping lesion) unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.

img Code C80.0, disseminated malignant neoplasm, unspecified, is for use only in those cases where the patient has advanced metastatic disease and no known primary or secondary sites are specified.

img When a primary malignancy has been previously excised or eradicated from its site and there is no further treatment directed to that site and no evidence of any existing primary malignancy, a personal history of malignant neoplasm code from Z85 should be used.


Anemia accounts for the largest portion of this chapter. In order to classify it correctly, detailed documentation is needed. Deficiency anemias can be due to blood loss, malabsorption of nutrients, or nutritional deficiencies. Hemolytic anemias, in which red cells are destroyed at an abnormal rate, can be hereditary or acquired. Aplastic anemia occurs when the bone marrow fails to produce the normal amount of blood components. The other major part of this chapter is coagulation defects—when the blood does not clot properly. The most well-known condition of this type is hemophilia. Diseases of the white blood cells, with the exception of leukemia, also are in this chapter. Leukemia is in the neoplasms chapter.

Diseases of the spleen are included in this chapter, as are complications of spleen procedures.

There are no official coding guidelines related to this chapter.


Endocrine glands secrete hormones directly into the bloodstream. The hormones travel to target organs and often are involved with metabolism, the chemical processes that take place in living tissues that are necessary for the maintenance of the organism. A disease state in an endocrine gland can affect not only the target organ but also related systems. This is demonstrated clearly in the complications of diabetes, which can affect the kidneys, eyes, nerves, and peripheral vascular system.

"Is this question part of your assignment? We can help"