A measure that would prevent a cut to Social Security payments failed in the Senate. As a result, rising Medicare Part B premiums are expected to adversely affect 27% of Medicare beneficiaries.

Medicare Part B premiums, which are taken directly out of seniors’ Social Security checks, are set to rise next year. Because there will be no cost-of-living adjustment to Social Security, millions of seniors will effectively see their incomes cut if the premium hikes pass, according to lawmakers objecting to those cuts. The House last month voted 406-18 to stop the Part B increase, but similar efforts in the Senate have fallen short.

The measure collapsed because of an objection raised by Sen. Tom Coburn (R-OK) on Wednesday. He argued that enough seniors–roughly 73%–would be spared the cuts due to a “hold harmless” provision, and that the $2.8 billion cost of preventing the premium hike would take money away from other constituents.