A proposal by the Centers for Medicare and Medicaid Services to publicly release pricing data that is used when insurers make bids on Medicare Advantage plans has garnered fierce opposition from — you guessed it — insurance companies.

As is the case for the Affordable Care Act individual insurance market, insurers that seek to offer Medicare Advantage plans must annually submit bids outlining the premiums they will charge. They are required to justify the premiums by submitting their projected medical loss ratio, or the amount of premium revenue that will be directed towards medical care, rather than profit.

“(W)e have the authority to use such information for purposes of improving public health through research on the utilization, safety, effectiveness, quality and efficiency of health care services,” explained the agency in a brief announcing the proposed rule change in July.