Internal Medicine Coding Alert

Question: The internist performs ambulatory blood pressure monitoring (ABPM) on a Medicare patient who he suspects has white-coat hypertension. What is white-coat hypertension, and how should I code for the ABPM service?

Idaho Subscriber

Answer: White-coat hypertension occurs when a patient has high blood pressure during office visits, but has normal BP in other settings. ABPM allows internists to measure the patient's BP over a 24-hour setting. The ABPM reading reveals whether the patient actually has high BP or it is a result of being in the physician's office.

Medicare will cover ABPM for patients with suspected white-coat hypertension.

In order to get the ABPM paid, you must show that:

• the patient had blood pressure readings of greater than 40/90 mm Hg during at least three separate office visits (the internist must make two separate measurements at each of these visits);

• the patient had at least two documented blood pressure measurements taken outside the office that are less than 40/90 mm Hg; and

• the patient has no evidence of end-organ damage.

When the physician performs ABPM to test for white-coat hypertension, Medicare requires a diagnosis code of 796.2, Elevated blood pressure reading without diagnosis of hypertension. (Note: Commercial carriers may, or may not, accept more ICD-9 codes as proof of medical necessity for ABPM. Check your individual carrier contract to see if private insurers are more lenient on APBM diagnosis coding.)

As for the ABPM, choose one of the following codes based on the internist's actions:

• Report 93784 (Ambulatory blood pressure monitoring, utilizing a system such as magnetic tape and/or computer disk, for 24 hours or longer; including recording, scanning analysis, interpretation and report) when the internist performs the complete ABPM procedure, including interpretation and report.

• Report 93786 (... recording only) when the internist provides the devices needed to perform ABPM but does not provide any physician interpretation or report.

• Report 93788 (... scanning analysis with report) when the internist provides only ABPM scanning analysis and report.

• Report 93790 (... physician review with interpretation and report) when the internist provides only the interpretation and report, not the technical services.