WASHINGTON (November 16, 2012)--The government says Medicare premiums are going up $5 a month for 2013, less than expected, but still enough to eat up nearly one-fourth of the typical cost-of-living raise for retirees.

Medicare chief Marilyn Tavenner said the monthly premium for 2013 will be $104.90 a month.

Also known as the Part B premium, it covers outpatient care such as office visits and medical supplies.

Taxpayers pay 75 percent of the cost for Part B benefits, and the monthly premium covers the remaining 25 percent.

High-income beneficiaries face bigger increases, from $42 to $230.80 a month while most low-income beneficiaries have their premiums paid by Medicaid.

Initially, premiums for 2013 were forecast to go up as much as $9 a month, but health care inflation has remained modest.