Required Minimum Distributions Can Compress Social Security Value by 30%

The real after-tax value of Social Security benefits can be compressed by 20% to 30% through a combination of taxes and Medicare premiums.

This erosion occurs when Required Minimum Distributions (RMDs) from a traditional 401(k) stack on top of Social Security income. For a retiree with an $800,000 balance at age 75, an RMD of $35,000 added to Social Security benefits of $28,000 creates a provisional income of $49,000. This figure exceeds the $34,000 threshold for single filers, pushing the benefits into the 85% taxability zone. Consequently, up to 85% of those benefits—roughly $23,800—become ordinary taxable income.

Combined with the RMD, the retiree reports taxable income of nearly $59,000.

Beyond taxes, modified adjusted gross income above $109,000 triggers Medicare IRMAA surcharges. These surcharges range from $90 to over $500 monthly per person. Because Medicare uses a two-year lookback rule, income reported in 2026 will determine premiums in 2028.

The combined impact of these taxes and premiums reduces the real value of Social Security by 20% to 30%.