Infectious Disease Prior Authorization and Denial Guide
Consultation code rules by payer, outpatient parenteral antibiotic therapy (OPAT) billing framework, hepatitis C direct-acting antiviral prior authorization requirements, HIV management coding, and inpatient subsequent care documentation, grounded in CMS Transmittal 1875 (consultation code rules), IDSA/AASLD HCV Guidance, and ACA §1557 nondiscrimination rules applicable to HIV and HCV treatment coverage.
HCV direct-acting antiviral (DAA) prior authorization: sofosbuvir/velpatasvir (Epclusa), glecaprevir/pibrentasvir (Mavyret), and ledipasvir/sofosbuvir (Harvoni) require prior authorization from all commercial payers and Medicaid programs. Documentation requirements include confirmed HCV RNA and genotype testing, fibrosis staging (FibroSure, elastography, or biopsy showing the fibrosis score), current medications for drug interaction review, and HIV status. Some state Medicaid programs have removed fibrosis restrictions and now cover DAAs for all HCV patients regardless of fibrosis stage, following ACA §1557 litigation outcomes. Commercial payer restrictions on fibrosis stage have been largely removed, but substance use disorder requirements at some payers have been legally challenged.
OPAT billing: outpatient parenteral antibiotic therapy for conditions including SSTI, osteomyelitis, endocarditis, and bacteremia requires a specific billing framework. The clinical management visits during OPAT are billed as subsequent office visits (99211–99215 for established patients) or as home health evaluation visits depending on where the patient is seen. Drug administration codes and the infusion drug itself are billed under HCPCS Level II codes. Infusion drug prior authorization requires documentation of the organism, antibiotic selection rationale (culture and sensitivity results), and expected duration.