Colorado "birthday rule" confusion leads to denied NICU claims for second family

A second Colorado family reports a NICU claim denial due to confusion over the "birthday rule" for newborn coverage. The rule determines which parent's insurance is primary for a newborn based on the parents' birth dates, but families and providers often misapply it, leading to coverage gaps and denials for expensive neonatal care. This is not an isolated payer policy but a systemic coordination-of-benefits failure. Practices should update newborn registration protocols to explicitly ask for both parents' insurance details and birth dates at admission. Verify primary coverage with both payers before billing, not after. Monitor for similar denials in pediatrics and OB/GYN; incorrect COB assignments trigger recoupments.