7. Overlooking Medicare Premium Surcharges (IRMAA)

Your Social Security payment and your Medicare premiums are inextricably linked. For most retirees, the baseline Medicare Part B premium is deducted directly from their monthly Social Security check before the money ever reaches their bank account. When planning a budget, you must account for this automatic reduction.

However, the trap lies in a surcharge known as the Income-Related Monthly Adjustment Amount (IRMAA). If your Modified Adjusted Gross Income (MAGI) from two years prior exceeds certain high-income thresholds, Medicare tacks a heavy surcharge onto your Part B and Part D premiums. This means a sudden financial windfall—such as selling a rental property, executing a large Roth conversion, or recognizing massive capital gains—can dramatically reduce your Social Security check two years later.

Because IRMAA operates on a cliff system, earning just one dollar over the threshold triggers the entire penalty tier. Retirees must engage in precise tax planning to stay under these cliffs. If you trigger IRMAA due to a life-changing event like retirement, marriage, or divorce, you can appeal the surcharge using Form SSA-44, but you must take proactive steps to file the paperwork.