If you file an individual tax return and your income is above $106,000, or if you are married and file a joint tax return and your income is above $212,000, Social Security will use the income reported two years ago on your IRS income tax return to determine your premium (if unavailable, SSA will use income from three years ago).
For example, the income reported on your 2023 tax return will be used to determine your monthly Part B premium in 2025. If your income has decreased since 2023, you can ask that the income from a more recent tax year be used to determine your premium, but you must meet certain criteria. At the end of each year, Social Security will send you a letter if your Part B premium will increase based on the level of your income and to tell you what you can do if you disagree.
For more information about Part B premiums based on income, call Social Security at 1-800-772-1213. TTY users should call 1-800-325-0778.
(Primary Source: Centers for Medicare and Medicaid Services - Medicare and You Handbook. This content may have been enhanced by Q1Group LLC to include further examples, explanations, and links.)