Coding and Documentation: A Brief Guide

Dipesh Navsaria, MPH, PA-C


September 12, 2001

In This Article

Coding the Diagnosis

The ICD-CM Code

The first step is to provide a diagnosis. The same patient could have the same condition described in multiple ways, so the standard system of coding diagnoses is called the International Classification of Diseases, Clinical Modification (ICD-CM). The 10th revision (ICD-10-CM) will be available through the National Center for Health Statistics ( in November 2001. Several University Web sites offer access to ICD-9-CM codes online ( (The ICD, developed by the WHO, is used to code and classify mortality data from death certificates.) The ICD-CM manual contains codes assigned to each medical condition, for example, 382.9 is the code for acute otitis media. The code can be used to identify a location (789.3 is the code for abdominal pain in the right lower quadrant, whereas 789.2 is the left upper quadrant). It can also clarify the nature of the condition -- for example, 382.9 might be the code for otitis media, but 382.01 specifies otitis media with spontaneous rupture of ear drum.

Revisions of the ICD-CM can affect diagnosis coding, so it is important to use the most current accepted version. There were 2 options for coding asthma -- 493.00 (asthma) and 493.01 (asthma with status asthmaticus). Basically, the options came down to "person about to die from asthma" and "everyone else with asthma." Code 493.00 encompassed everyone from the patient being seen for a routine medication review to the patient having a moderate flare-up of asthma symptoms that was managed in the office instead of during an expensive emergency room visit. Accordingly, 493.02 was added this year to the ICD-10-CM for "asthma exacerbation." When an insurance company receives the bill, using the 493.02 code indicates to them the nature of the visit in a more specific manner.

Besides the numerical codes, there are the "V" codes -- "supplementary classification of factors influencing health status and contact with health services (V01-V82)." For example, you really can't claim a child is ill when they are there for a routine physical on which nothing is found. Hence the V20.2 code is used for routine infant or child health check. V codes also cover routine employment physicals (V70.3), general gynecologic examination (V72.3), general psychiatric examination (V70.2), eye and vision exam (72.0), special screening for endocrine, metabolic, and immunity disorders (V77), and so forth.

Be careful with the V codes, however. Many insurers will not pay for visits for which the diagnosis is simply a V code, with the exception of physicals, and, even then, they will only pay for 1 adult physical a year. For example, if a parent brought their child in for a well-child checkup because the child's school needs the form filled out, but it had only been 8 months since the last visit, the second physical would be the financial responsibility of the parent.

There are also the "E" codes -- "supplementary classification of external causes of injury and poisoning (E800-E999)" -- which are used in tandem with the other codes to indicate the cause of external injury or poisoning. Some very unusual methods of injury are presented in the E codes -- eg, E845 (accident involving spacecraft); E844 (sucked into jet without accident to aircraft); E833 (fall into hole); E884.6 (fall from commode); E907 (struck by lightning).

Most of the ICD-CM manuals are arranged in 2 parts, with the first part listing conditions alphabetically and the second listing them by number. Although the alphabetical list is probably used the most, it's not as comprehensive as the numerical listing. One trick to find a condition that's reasonably close to the one being treated and then to look up the number provided. Somewhere in the vicinity of that number should be the exact condition you're looking for.

The codes convey to insurance carriers what you found. That was the easy part. Telling them what you did is not so easy.