Who'll Qualify for the Minimum Part B Premium?

A. The answer is yes, provided that the income figure you're quoting was true for 2011. It can be confusing, but Medicare Part B premiums are based on your income of two years earlier.  In 2013, a husband and wife filing a joint tax return will each pay the minimum Part B premium if their combined income in 2011 was $170,000 or less. For 2013, that premium has been set at $104.90 a month, a $5 increase over 2012.

The money will be deducted from the monthly Social Security checks of both the husband and the wife.

Medicare Part B pays for doctors, medical tests and medical equipment.

There are five premium levels, depending on annual income and tax filing status. For instance, the minimum $104.90 monthly premium that you and your husband will pay will also be paid by people who filed for 2011 as individuals and had income of $85,000 or less. The top premium of $335.70 will be paid by individual filers who had income of more than $214,000 in 2011 and couples who had income of more than $428,000.

To get technical, "income" here means modified adjusted gross income, generally the sum of your adjusted gross income (line 37 on your Form 1040) and tax-exempt interest income (line 8b).

All of the premiums are going up by 5 percent.

Keep in mind that if you have Part B insurance, you'll also have to pay an annual deductible before your benefits kick in. In 2013, the deductible will be $147, up from $140 in 2012.

For more information about Medicare costs for 2013, call 800-MEDICARE (800-633-4227).

Stan Hinden, a former columnist for The Washington Post, wrote How to Retire Happy: The 12 Most Important Decisions You Must Make Before You Retire. Have a question for the Social Security Mailbox? Check out the archive. If you don't find your answer there, send a query.