Dozens of Democrats have joined Republicans in calling on the administration to keep Medicare Advantage rates flat to avoid cutting benefits for seniors.

The program has been championed by Republicans as a private market alternative to Medicare. Under the program, seniors can enroll in a plan offered by a private insurer, and the federal government pays the insurer directly.

Support for the program is a reversal for many Democrats, who have historically lampooned the alternative to government health insurance as receiving outsized federal support in comparison to Medicare. The Democratic-led Congress that passed the Affordable Care Act partially paid for it by enacting $200 billion in cuts to Medicare Advantage over 10 years.

The administration will announce 2015 rates for Medicare Advantage on Monday.