Internal Medicine Coding Alert

Internal-medicine offices and primary-care clinics recently have been beset by a rash of flu cases and a people seeking flu vaccinations. Billers should be careful when assigning ICD-9 codes for visits for the flu and for visits for vaccinations. If there is no definitive diagnosis, code the symptoms that are documented.

First, you should use only an influenza code (487.x) when the documentation clearly indicates that the physician diagnosed the patient with the flu. Unless there are complicating circumstances, the physician rarely orders the viral studies necessary to determine the actual presence of the influenza virus, says Jeri Leong, CPC, an independent coding consultant based in Honolulu.

Most of the time, it is a clinical diagnosis based on presenting symptoms, she says. If the physician diagnoses influenza or flu, the appropriate ICD-9 category is 487.x. If a definitive diagnosis is not made, Leong recommends coding the symptoms as the physician documented them (e.g., nausea with vomiting [787.01] and/or chills and fever [780.6]).

Different Flu Diagnoses

Several diagnosis codes exist within the category of influenza, Leong notes. These are:

487.0influenza with pneumonia

487.1influenza with other respiratory manifestations

487.8influenza with other manifestations

The last subcategory also includes flu with gastrointestinal (GI) symptoms, she says. However, coders should be sure to differentiate between influenza with GI symptoms (487.8) and intestinal flu (008.8), she adds. Also, influenza with pneumonia (487.0) should not be confused with pneumonia due to parainfluenza virus (480.2), she says.

Note: Intestinal flu actually indicates a bacterial infection instead of a viral infection as with influenza. That is why it would be reported with 008.8 (intestinal infections due to other organisms, not elsewhere classified).

Coding for Flu Vaccines

Some offices also are making the mistake of assigning a 487.x ICD-9 code when a patient is given the influenza vaccine. This is incorrect. The appropriate diagnosis code for a flu vaccination is V04.8 (influenza vaccination), Leong says. Medicare covers the annual administration of the flu vaccine, as do most other payers.

To report the flu vaccine for Medicare patients, you should choose the CPT code for the specific vaccine given (90658-90660) in addition to code G0008 for the vaccine administration.

For non-Medicare patients, use codes 90657-90660, depending on the type of vaccine (split or whole virus, live, jet or intramuscular injection) given, and code 90471 for the vaccine administration.

Note: According to HCPCS 2000, G0008 can be reported only when there is no other physician service covered under the fee schedule performed that same day