Will a one-time increase in my income (for example, due to property sales or capital gains) affect my Part B premium forever?

No. Each year Social Security will request your most recent tax return information from the Internal Revenue Service (IRS) to determine your current Part B premium. IRS generally provides information for two years prior to the year in question. For 2010, we generally would use your 2008 tax return information. We use your modified adjusted gross income (MAGI) from your income tax return to determine your premium for one year. Your MAGI is a combination of your adjusted gross income and tax exempt interest income.

In the example, your 2008 tax return will reflect only your income for that year. So, if your premium increased in 2010 because you sold a property in 2008, it could decrease in 2011.

For more information, see Social Security's publication, Medicare Part B Premiums: New Rules For Beneficiaries With Higher Incomes, call Social Security toll-free at 1-800-772-1213 (TTY 1-800-325-0778) or visit your local Social Security office. You can find additional answers on Part B Income-Related questions on the Social Security website.

To learn more about Medicare Part B coverage, visit www.medicare.gov.