UHC uses Renew now (no idea why they bailed from SilverSneakers). I'd suspect they don't absorb the cost though because the G+ with Renew, dental and eye costs about $70/mo more (when I compared it for a 71 non-smoking female year old last Nov) than the G without them (not all states have both, supposedly they are slowly rolling that out nationwide). So much for "no cost to you" extra benefits that G+ offers.Carriers that offered SilverSneakers found that roughly 15% actually used the program.
SilverSneakers charges carriers a flat fee which is absorbed by carriers that offer the program with MA or Medigap plans.