Many Medicare beneficiaries will pay higher monthly premiums next year for outpatient coverage, eating away at an increase in their Social Security checks.

That's in the fine print from an announcement by Medicare late Friday.

Although the standard "Part B" monthly premium will stay the same next year—$134—many beneficiaries will still have to pay more. It's because their Social Security checks are going up 2 percent after several years of little or no cost-of-living raise.

Many of those affected are now paying $109 a month, so they'll owe $25 more.

The Part B deductible will stay the same, $183. That's the annual amount patients pay for before insurance kicks in.

But the inpatient "Part A" deductible will go up by $24, to $1,340.