Under Texas Insurance Code §542.055, within how many days after receiving notice of a claim must an insurer acknowledge receipt of the claim?

Why this is the answer

Texas Insurance Code §542.055 is part of the Prompt Payment of Claims subchapter (Chapter 542, Subchapter B), which applies to life, health and accident insurers among others. It requires an insurer, not later than the 15th day after it receives notice of a claim (the 30th business day for an eligible surplus lines insurer), to acknowledge receipt of the claim, commence any investigation and request the items it reasonably believes it will need. The insurer must then accept or reject the claim in writing not later than the 15th business day after receiving all required items (§542.056), or say why it needs more time and decide within 45 days, and pay an accepted claim within 5 business days (§542.057). An insurer liable for the claim that misses these deadlines owes 18% a year interest plus attorney's fees (§542.060(a)). The separate list of unfair claim settlement practices is in §542.003, which includes failing to acknowledge claim communications with reasonable promptness.