Core Insights - Medicare premiums for Parts B and D can increase based on household income, specifically through the Income-Related Monthly Adjustment Amount (IRMAA) [6][20] - The IRMAA is applied annually and is determined by a two-year lookback period of income [10][14] Medicare Parts Overview - Medicare Part A covers hospital treatment and most people do not pay a premium for it, unless based on work history [4] - Medicare Part B covers outpatient treatment and has a base premium of $185 per month starting in 2025, which is adjusted based on income [2][8] - Medicare Part C is a public/private partnership that allows Medicare coverage to help pay for private insurance, typically requiring monthly premiums [3] - Medicare Part D primarily covers prescription medicine and also has a premium that varies by plan and can be adjusted based on income [1][9] IRMAA Details - For 2025, Part B IRMAAs start at incomes above $106,000 for individuals and $212,000 for joint filers, with premiums increasing to as high as $628.90 for incomes above $500,000 [8] - Part D IRMAAs also begin at the same income thresholds, with additional monthly charges ranging from $12.90 to $81 depending on income levels [9] Income Considerations - Medicare premium adjustments are based on Modified Adjusted Gross Income (MAGI), which includes adjusted gross income plus tax-exempt interest [7] - Withdrawals from retirement accounts can affect future Medicare premiums, but the impact is not immediate due to the two-year lookback rule [15][18] - Managing income and withdrawals can help mitigate premium increases in subsequent years [19]