The government just announced the 2015 premiums for Medicare Part B, and they remain unchanged for everyone. Most individuals pay $104.90 for Part B, but those with higher incomes (single filers making over $85,000 and married copies with income over $170,000) do pay more. Also announced, the government will be keeping the Medicare Part B premium at $147; the deductible fore Part A (hospitalizations) will go up slightly to $1260, up $44 from the 2014 deductible. Most Medicare recipients have other insurance that helps pick up this cost.
In many articles and quotes by Obarma's Administration, they are touting the reason for not raising the premiums is due to the slowing of healthcare costs and a direct result of items implemented from the ACA law. However, it is hard to say how much the healthcare law is contributing to slow Medicare spending growth. Some economists have debated the point with the administration, arguing that the recovering economy is the key factor. Meanwhile, the under 65 market is getting hit with much larger increases, which is really what the bulk of the ACA law addresses. "Obamacare" was really a reform for the under 65, but it did throw in a few good measures for seniors on Medicare, including adding a wellness exam.
Bloomberg Blog: Medicare Premiums unchanged