N.Y. Comp. Codes R. & Regs. tit. 9, § 210.6
(d) If the claim is denied, the benefit provider shall mail or deliver written notification to the claimant and the fire district, department or company within five business days of the denial. If the benefit provider making the denial is an insurance company, then the written denial notification shall include a statement that the claimant may file a complaint with the New York State Department of Financial Services and provide the department’s website address, mailing address, and telephone number. Any denial notification by a benefit provider shall include the reasons for such denial. The only permissible reason(s) for denial of a claim shall be the following:
(a)