A 25% IRS penalty applies if you miss your Required Minimum Distribution 2026 deadline. That is a costly mistake. RMD rules require withdrawals from traditional IRA and 401(k) accounts at age 73. The distribution is taxable income. It can raise your tax bracket. It may increase Medicare IRMAA premiums. Early withdrawal reduces penalty risk. Waiting allows tax planning flexibility. Review income projections carefully. Compliance and timing both matter.