some denials do happen. the bigger systemic issue, by far, and probably ultimately harder to rein in, is the enrollee health status gaming
Are you referring to things like HRAs and other data collection methods to try to indicate that health is worse than it is? Incentivizing clients to think of any health conditions so that they can get a $50/mo grocery card (and the insurer makes more $$).
It's a racket.
Carriers in the MAPD market love a sick(er) enrolee -- more $.
They're just as bad as a doctor who sees a slight shadow on their imaging machines...ready to pounce.