Primary Care Coding Alert

Question: We have a patient who was diagnosed with white coat hypertension. Is there an ICD-9 diagnosis for this?

Idaho Subscriber

Answer: Use 796.2 (Elevated blood pressure reading without diagnosis of hypertension) as your ICD-9 diagnosis. Remember that white coat hypertension (WCH) is diagnosed only when a patient has elevated BP in the clinic setting but otherwise has normal BP outside the office. According to Medicare's Internet Only Manual (IOM) Publication 100-04 Chapter 32 Section 10, WCH should be suspected when a patient has:

1. Clinic/office blood pressure >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 < 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 only cover ABPM for patients with WCH. In addition, ABPM must be done for at least 24 hours to meet coverage criteria.