The processing carrier shall pay, decline to pay, or settle each written or electronically communicated claim within 60 days after its receipt by that carrier, except where the claimant and the carrier agree in writing or electronically to a specific extension based upon extenuating circumstances. If the carrier declines to pay a claim or makes settlement in an amount different from that sought, the carrier shall notify the claimant in writing or electronically, of the reason(s) for its action, citing tariff authority or other pertinent information developed as a result of its investigation. [47 FR 12804, Mar. 25, 1982]