Retroactive claim denials claw back payments from providers months after services were rendered

Insurers deny or retroactively recoup claim payments 90-180 days after a service was rendered and initially approved, citing post-payment audit findings like coding technicalities or eligibility verification gaps that the provider had no way to catch at time of service. A small pediatric practice delivers a round of vaccinations, receives payment, then three months later gets a demand letter clawing back $8,000 because the insurer retroactively determined the patient's coverage had a 2-day gap. The practice has already paid the nurse, bought the vaccines, and reported the revenue. This persists because insurer-provider contracts typically grant insurers 12-24 month clawback windows with no reciprocal right for providers to rebill after the same period, and small practices lack the legal resources to challenge recoupment demands.