For those average retirees, who enrolled this year for the first time in Medicare and received Social Security benefits in 2016, they will enjoy the luxury of having their Medicare Part B premiums only inflate by their Social Security COLA amount.
Thus, for the average retiree who enrolled in Medicare in 2016, his or her take-home Social Security benefit should remain the same as the previous year — but please keep in mind that these scenarios only happen if there is a 0.2 percent or greater COLA from Social Security.
According to the Medicare Board of Trustees, "If the Social Security COLA is actually zero percent for 2017, then the provisions of the Bipartisan Budget Act of 2015 would be triggered, and the 2017 Medicare Part B premium would increase without the hold-harmless provision effects."
This means that if there is no COLA for retirees, then — due to federal regulations — every retiree will see his or her Medicare Part B premiums increase to at least $149, as no retiree will be protected by the Hold Harmless Act, thus decreasing every retiree's Social Security benefit.
So for those who enrolled in Medicare prior to 2016 and who were already held harmless in 2016 from increases in Medicare premiums in 2015, they will see their Social Security benefits decrease by $41.43 a month if there is no COLA.