The majority of enrollees in Medicare Part B pay a premium of $104.90 per month in 2015, according to the U.S. Department of Health & Human Services. About 5 percent of beneficiaries pay higher income-related monthly premiums.
About 95 percent of Medicare Part B beneficiaries are either single tax filers and have income of $85,000 or they file tax returns jointly and have $170,000 or less per year, explains the U.S. Department of Health & Human Services. They pay the standard monthly premium. The highest premiums, $230.80 and $335.70, are paid by beneficiaries with annual incomes greater than $214,000, if filing singly, or greater than $428,000, if filing jointly.