Internal Medicine Coding Alert

Question: We have a patient who was diagnosed with white coat hypertension. Is there an ICD9 Codes

for this?

Idaho Subscriber

Answer: Use 796.2 (Elevated blood pressure reading without diagnosis of hypertension) as your ICD-9 code. Remember that white coat hypertension (WCH) is diagnosed only when a patient has elevated blood pressure (BP) in the clinic setting but otherwise has normal BP outside the office.

According to Medicare Claims Processing Manual,Chapter 32, Section 10, WCH should be suspected when a patient has all three of the following:

1. clinic/office blood pressure greater than 140/90 mm Hg on at least three separate clinic/office visits with two separate measurements made at each visit

2. at least two documented separate blood pressure measurements taken outside the clinic/office that are less than 140/90 mm Hg, and

3. no evidence of end-organ damage.

To establish a diagnosis of white coat hypertension, the patient undergoes ambulatory blood pressure monitoring (ABPM). Medicare will cover ABPM only for patients with WCH. In addition, ABPM must be done for at least 24 hours to meet coverage criteria. A device stores the 24-hour measurements so the physician can interpret them. "In the rare circumstance that ABPM needs to be performed more than once for a beneficiary, the qualifying criteria described above must be met for each subsequent ABPM test," the manual states.

CPT: The following codes describe ABPM:

• 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
• 93786 -- ... recording only
• 93788 -- ... scanning analysis with report
• 93790 -- ... physician review with interpretation and report.