How long does the secondary insurance carrier have to pay a bill once the explanation of benefits is received from the primary carrier?

Normally, the health care provider will collect primary and secondary insurance information from the patient at the time of treatment. The provider will bill both insurers, and the primary insurer will pay its share. Both insurers are subject to the "prompt pay law" of the State in question, and payment by the respective companies of their shares must be made within that period. Otherwise, there is at least a technical violation of the State's Insurance Code. The "prompt pay law" may provide that the late-paying insurer must pay interest on the late payment.