Reimbursement
Complaints allege plans offered by insurers are discriminatory because they don't cover drugs essential to HIV treatment.
481 participating practices served more than 376,000 Medicare beneficiaries, 2.7 million patients overall, CMS says.
Numerous Kaiser plans score high marks, while Tenet and Health Care Services plans among low scorers.
Forty-three percent of returning consumers to the federal government's online exchange, healthcare.gov, switched policies last year.
Insurer said it is still trying to negotiate a new contract with the major public hospital operator.
Huge final rule already has healthcare pros celebrating or lamenting the release.
Provider network can be an important factor for some consumers, especially given the growing number of plans with no out-of-network benefits.
Program cements two payment tracks and "pick your pace" approach while setting aside money to support small practices.
Federal officials send letters to beneficiaries explaining that they can keep exchange plans but lose subsidies since they are eligible for Medicare.
Industry watchdog is calling on CMS to allow insurers even more flexibility and to expand the pilot program to all states.