Medicare has updated ICD-10 codes and billing for PrEP services. Key codes include Z29.81 (PrEP encounters) and Z11.4 (HIV screening), with expanded codes effective 4/7/2025. For FQHCs, use G0011 for counseling by physicians and G0013 for auxiliary staff starting 9/30/2024. Injectable PrEP (J0739) and oral drugs (J0750) require 340B modifiers under the Inflation Reduction Act. From 1/1/2025, Medicare will cover PrEP drug costs on a claim-by-claim basis.