Summary & Overview
HCPCS Level II S0137: Didanosine (ddi), 25 mg
HCPCS Level II code S0137 denotes Didanosine (ddi), 25 mg, an antiretroviral medication formulation used in HIV care. Nationally, accurate coding for specific drug formulations matters for pharmacy reimbursement, formulary management, and continuity of care for patients receiving combination antiretroviral therapy. Clear identification of drug-dose codes supports proper claims adjudication and inventory control across payers.
Key payers in the analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of code definition and clinical context, payer coverage considerations, and benchmarking insights where available. The publication outlines typical sites of service, common billing practices for drug-specific HCPCS Level II codes, and what information is typically required by payers for adjudication.
This summary is intended for clinicians, pharmacy billing staff, and policy analysts seeking a national perspective on the use and administrative handling of HCPCS Level II code S0137. Data not available in the input is noted where applicable; the focus is on code purpose, service context, and payer relevance.
Billing Code Overview
HCPCS Level II code S0137 represents Didanosine (ddi), 25 mg. This code denotes a specific oral antiretroviral medication dose formulation used in the treatment of human immunodeficiency virus (HIV) infection. The service type is pharmacy-dispensed antiretroviral medication.
Typical site of service for S0137 is outpatient pharmacy or clinic-based dispensing, including specialty pharmacies that supply antiretroviral therapies.
Clinical & Coding Specifications
Clinical Context
A 42-year-old patient with chronic HIV infection presents to an outpatient infectious disease clinic for antiretroviral medication management. The clinician prescribes didanosine (S0137, didanosine 25 mg) as part of a salvage regimen when other nucleoside reverse transcriptase inhibitor options are limited by resistance or intolerance. The clinical workflow includes medication reconciliation, adherence counseling, baseline laboratory testing (HIV viral load, CD4 count, hepatic panel, pancreatic enzymes, and fasting lipid/glucose as indicated), and education regarding proper administration (taking didanosine on an empty stomach and avoiding concurrent antacids containing magnesium or aluminum). The medication is dispensed from the clinic or a specialty pharmacy; documentation includes the drug name, S0137 HCPCS code, dosage, quantity, route (oral), date of dispensing, and lot number. Follow-up visits monitor viral suppression, adverse effects (peripheral neuropathy, pancreatitis, hepatic toxicity), and laboratory surveillance. If acute adverse events occur, the patient may be evaluated in urgent care or the emergency department, and dosage adjustments or discontinuation are documented in the medical record.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | No modifier / standard service |