Answer: The key to determining whether two E/M services are separately payable when provided to the same patient on the same day is whether the E/M services were rendered during separate encounters and for unrelated problems.
In the situation you describe, the two times you saw the patient, the morning and afternoon, meet the requirement that the E/M services be provided at separate encounters, and the separate diagnoses hypertension and knee pain constitute the "unrelated problems" requirement. So you can bill for both visits.
Section 15502(B) of the Medicare Carriers Manual (MCM) states that carriers should pay for two office visits billed by a physician for the same patient on the same day if "the physician documents that the visits were for unrelated problems in the office or outpatient setting which could not be provided during the same encounter."
Be sure to send your notes with the claim to demonstrate that the two E/M services were for unrelated problems. You should also append modifier -25 (Significant, separately identifiable evaluation and management service by the same physician on the same day of the procedure or other service) to the second E/M code, although the MCM does not specify that you should do so. If the claim is rejected, you should appeal the rejection by citing the above statement from the MCM.
If you get a denial, you should appeal your modifier -25 denials because you deserve payment for those E/M services. But before you appeal, make sure you're correctly appending modifier -25. When you appeal your claims, send a copy of the chart notes to prove that the E/M service was, in fact, a separately identifiable service.
You should, of course, send the chart notes the first time, but they often get overlooked or lost. If payers see the charts on an appeal, they'll probably pay attention to them since they explain the reason for appeal.
If you're still having trouble getting your claims paid, contact the payer's representative.
