In December 2019, I had surgery for a herniated lumbar disc. Medicare, which provides my health insurance, works thusly: Doctors who accept Medicare assignments (some don’t) agree to accept as full payment not the amount they charge but the “Medicare Approved Amount” (MAA) for the service rendered. Once I've paid the annual deductible, Medicare pays 80% of the MAA; I pay the other 20%, which is the maximum the doctor should charge me.

Before the surgery, I had to pay the hospital and the surgeon the amount that presumably was my 20% co-pay. A few weeks after the surgery I got a bill (for $40.28) covering 3 pre-surgery office visits. Some folks probably would have paid that bill without questioning it. Instead, I examined online (at MyMedicare.gov) the Medicare Summary Notice (MSN) covering each office visit. Result: instead of me owing the surgeon, he owed me, for I had paid more than the MSNs showed as the “Maximum You May be Billed”. The surgeon’s business office agreed to refund my overpayment. Moreover, it had billed me for a visit that the surgeon said was free. Per the MSNs, my prepayments to the hospital and the surgeon were correct.

This tale has a lesson for Medicare beneficiaries. I keep records of my doctor/hospital visits. Then when I receive a bill, I don’t just pay it; instead, I compare the MSN for each office/hospital visit with the amount that I was billed. In 2019, this procedure resulted in another doctor refunding to me $98.00 that I had overpaid him.