Dear Liz: When I retired at age 70, I anticipated receiving the maximum available Social Security benefit payment because I had paid in the maximum tax for my entire career. I did not anticipate the heavy hit my spouse and I would take in monthly income-adjusted Medicare “premiums.” (I say “tax” is a more appropriate description.) We now pay over $500 per month each, or more than $12,000 per year! I know I am blessed to have the income I have in retirement, but that is because we were thrifty and worked hard and saved.

Answer: Many high-income retirees are unaware of “IRMAA,” or Medicare’s income-related monthly adjustment amounts, so they can come as a bit of a shock. These adjustments begin when modified adjusted gross income exceeds $85,000 for singles or $170,000 for couples. At that level, Medicare recipients pay an additional $53.50 for Part B, which covers doctor’s visits, and $13.30 extra for Part D prescription drug coverage, on top of their regular premiums. (Regular premiums for Part B are $134 a month, while premiums for Part D vary by the plan chosen.) The adjustments increase as income rises until they max out at $294.60 for Part B and $74.80 for Part D when modified adjusted gross income exceeds $160,000 for singles or $320,000 for couples.

Medicare Part A, which covers hospital visits, remains free for all Medicare beneficiaries.

That $12,000 a year may feel like a lot, but healthcare is expensive in the U.S. Annual premiums for employer-sponsored family health coverage reached $18,764 last year.