Of Course, By This Time Next Year Medicare As We Know It May Be Gone -- November 19, 2016

But for now, the Medicare premiums for 2017 have been released: link here. This is what I was looking for:

Retirees don't all pay the same Medicare Part B premium. While most Medicare beneficiaries will experience a modest premium increase next year, a few specific groups of seniors will have to pay much higher premiums.

Existing Social Security beneficiaries. Medicare premiums are prevented by law from increasing faster than Social Security payments for existing beneficiaries. The Social Security cost-of-living adjustment was just 0.3 percent for 2017. So, the monthly Medicare Part B premium will only increase by a few dollars from $104.90 in 2016 to $109 in 2017 for most existing Social Security recipients.

New Medicare enrollees. Retirees who sign up for Medicare in 2017 will pay the standard Medicare Part B premium of $134 for 2017, up 10 percent from $121.80 in 2016. These new enrollees will pay $300 more for Medicare Part B in 2017 than existing Social Security recipients.

"Because of the 'hold harmless' provision covering the other 70 percent of beneficiaries, premiums for the remaining 30 percent must cover most of the increase in Medicare costs for 2017 for all beneficiaries," according to a statement from the CMS. New enrollees include people who will turn 65 in 2017 and those who were previously covered by group health insurance through their job and elect to join Medicare in 2017.