US retirees face Medicare premium spikes from discretionary 401(k) withdrawals
A recent analysis by Baird Private Wealth Management highlights how the Social Security Administration’s two-year look-back rule impacts IRMAA calculations, limiting options for immediate premium reductions.
US financial advisers are cautioning retirees against making discretionary withdrawals from traditional 401(k) plans to cover large expenses, as such moves can trigger significant increases in Medicare premiums. According to guidance published by Yahoo Finance, taking extra funds from a retirement account raises modified adjusted gross income, which directly influences the Income-Related Monthly Adjustment Amount (IRMAA). This surcharge applies to both Medicare Part B and Part D premiums, creating a financial drag that can persist for years.
The core of the issue lies in the Social Security Administration’s two-year look-back rule. IRMAA surcharges are calculated using tax data from two years prior to the current coverage year. Consequently, a large withdrawal made in the current tax year will not immediately affect premiums for that same year but will likely trigger higher costs in the following year. Once the higher income is reflected in the calculation, the surcharge remains in place until a lower-income tax year is processed, meaning the penalty can last for at least one full cycle of the annual recalculation.
Taxpayers often hope to avoid these surcharges by submitting forms to indicate that a high-income year was a one-off event. However, the Social Security Administration does not accept such requests for discretionary withdrawals. Premium reductions are only granted if the income change is tied to a qualifying life-changing event, such as retirement, divorce, or a substantial reduction in work hours. A voluntary withdrawal from a 401(k) or a Roth conversion does not meet this criteria, leaving retirees locked into the higher premium until the income naturally drops in subsequent tax years.
The financial impact of these surcharges can be substantial. For the 2026 tax year, the maximum IRMAA surcharge for a married couple in the highest bracket is estimated at approximately $6,936 per person annually, totaling $13,872 for a couple. Additionally, retirees may face a 3.8% net investment income tax on earnings associated with the withdrawal. Baird Private Wealth Management notes that while the withdrawal may still be net-positive after capital gains taxes, the IRMAA surcharge represents a significant tax drag that requires careful planning.
To mitigate these risks, financial institutions suggest strategic planning before required minimum distributions begin. Baird Private Wealth Management advises tapping retirement funds before age 73 to reduce account balances and future RMDs, thereby managing the income levels that trigger IRMAA. Recipients receive notices each December regarding premium adjustments, and those with modified adjusted gross income above $109,000, or $218,000 for couples, from two years prior will see higher premiums. The agency emphasises that premiums are recalculated annually, so a temporary spike does not necessarily mean a permanent increase, but proactive management is essential to avoid unexpected costs.
