So why did Medicare deny payment for your last mammogram, which you had done precisely on the anniversary of your previous imaging? For, I'm sorry to say, a very dumb reason.

Medicare requires that your annual screening mammography be done at least 366 or more days from your last imaging study. Yes, that's right: One year and one day (or more) must pass before you can have the next screening mammogram.

Of course if you have symptoms or a breast abnormality before that date, then they'll make an exception. This means that you're getting a diagnostic mammogram instead of a screening mammogram.

The purpose of a diagnostic mammogram is to determine the cause of the symptoms you're having or an abnormality that's been noticed, and to rule out the presence of cancer. This is quite different from a screening mammogram, which looks for unknown abnormalities.

But for your usual, routine, annual mammogram — when you're free of any bumps, lumps, or troubles — if your insurance is Medicare, be sure to schedule your next annual imaging study at least a year and a day (366 days) from your last one, or you'll get stuck with both the facility's bill for doing the mammogram and with the doctor's fee for reading the images. Ouch!! And you thought getting your breasts squeezed was the only ouch involved!