Summary & Overview

HCPCS S0138: Finasteride, 5 mg

HCPCS Level II code S0138 denotes Finasteride, 5 mg, a prescription oral medication dispensed through outpatient pharmacies or clinic dispensing. This code identifies the pharmaceutical product rather than an administration procedure, making it relevant for pharmacy billing, inventory tracking, and benefit coverage determinations across commercial and public payers. Nationally, accurate coding of prescription products like S0138 matters for claims adjudication, formulary management, and utilization monitoring.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of payer coverage considerations, typical sites of service for dispensing, and the clinical context in which finasteride 5 mg is used. The publication also outlines common billing modifiers associated with HCPCS Level II lines (input provided) and specifies where input data are missing.

This resource summarizes benchmarks and policy-relevant points for billing and coding teams, pharmacy operations, and revenue cycle professionals who manage outpatient medication claims. It provides concise clinical context, payer scope, and notes on data availability to support consistent application of HCPCS Level II code S0138.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareS0138HCPCS Level IIfinasteridepharmacy-dispenseoutpatient pharmacymedication billingpharmaceutical codingprescription drug

Billing Code Overview

HCPCS Level II code S0138 represents Finasteride, 5 mg, a prescription oral medication commonly used for androgenetic alopecia (male pattern hair loss) and benign prostatic hyperplasia in clinical practice. The service type associated with this code is pharmacy-dispensed prescription medication. The typical site of service is outpatient pharmacy or clinic-based dispensing where the medication is supplied to the patient.

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Clinical & Coding Specifications

Clinical Context

A typical patient is an adult male presenting to a primary care clinic or urology clinic for management of symptomatic benign prostatic hyperplasia (BPH) or androgenetic alopecia. The clinician documents a history of urinary hesitancy, decreased urinary stream, nocturia, or progressive male pattern hair loss. After evaluation including history, focused genitourinary exam, and review of current medications and contraindications (for example, pregnancy exposure risk to women of childbearing potential), the clinician prescribes S0138 (Finasteride, 5 mg) as a pharmacy-dispensed oral medication.

The clinical workflow includes medication counseling, documentation of indication and informed consent regarding potential sexual side effects and teratogenic risk, verification of insurance coverage and prior authorization if required, and scheduling follow-up (typically 3 months) to assess efficacy and side effects. For BPH, baseline prostate-specific antigen testing and digital rectal exam may be performed prior to initiation per clinician judgment. For hair loss, photographic documentation and discussion of expected timeline for response are recorded. Prescription is transmitted to a retail or specialty pharmacy; billing of S0138 occurs when the unit formulation matches the HCPCS Level II billing requirements for finasteride 5 mg.

Coding Specifications

Modifier	Description	When to Use
`00`	No modifier — standard service identification	Use when no special circumstance modifier applies to the medication billing.
`22`	Increased procedural services	Rarely used for drug billing; apply only if there is separately billable substantially increased work related to dispensing or on-site professional services documented.
`23`	Unusual anesthesia	Not typically applicable to outpatient oral drug billing; not used unless anesthesia exception applies to an associated procedure.
`52`	Reduced services	Use when a reduced service related to the visit or ancillary service is documented and affects billing for a bundle including the drug.
`53`	Discontinued procedure	Use if the associated procedure was started but discontinued and billing must reflect that context with the medication.
`54`	Surgical care only	Use when the billing relates to the surgeon’s portion only and the medication billing is tied to a surgical global period.
`55`	Postoperative management only	Use when only post-op care is billed and medication relates to that period.
`56`	Preoperative management only	Use when only pre-op care is billed and medication relates to that period.
`62`	Two surgeons	Use when two surgeons are involved and billing must reflect shared services that may affect supply or medication billing.
`78`	Unplanned return to the operating/procedure room by same physician following initial procedure for a related procedure during the postoperative period	Use when medication is billed in the context of an unplanned return to OR for a related complication.
`AS`	Student health service	Use when the service is provided in a student health context and payor requires this designation.
`CO`	Correction of error on prior claim	Use when resubmitting corrected billing for `S0138` after an identified claim error.
`CQ`	Service furnished under a workers' compensation claim	Use when the medication is furnished under workers' compensation coverage.
`QX`	Modifier indicating CRNA services with medical direction by physician (specific to anesthesia)	Rarely applicable; include only when anesthesia billing is associated and impacts global billing tied to the medication.

Taxonomy Code	Specialty	Notes
`208000000X`	Family Medicine	Primary care clinicians commonly prescribe finasteride for BPH and hair loss.
`208100000X`	Internal Medicine	Internists manage BPH and systemic medication therapy including finasteride.
`2084P0800X`	Urology	Urologists commonly initiate and manage finasteride for BPH and related prostate conditions.
`207Q00000X`	Dermatology	Dermatologists commonly prescribe finasteride for androgenetic alopecia in men.
`363L00000X`	Clinical Pharmacy	Pharmacists involved in dispensing, counseling, and prior authorization coordination for finasteride.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`N40.0`	Enlarged prostate with lower urinary tract symptoms	Primary indication for finasteride 5 mg to reduce prostate volume and improve urinary symptoms.
`L64.0`	Androgenic alopecia (male pattern hair loss)	Common dermatologic indication for finasteride to slow hair loss and promote regrowth in men.
`N40.1`	Nodular prostate with lower urinary tract symptoms	Variant of BPH where finasteride may be used to reduce gland size and symptoms.
`R35.0`	Frequency of micturition	Symptom often associated with BPH treated with finasteride as part of symptom management.
`R33.9`	Retention of urine, unspecified	Acute or chronic urinary retention related to prostatic obstruction where finasteride may be part of management strategy.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`99213`	Office or other outpatient visit for the evaluation and management of an established patient, typically 15 minutes	Common visit level for follow-up or initiation visit where finasteride is prescribed and counseling is provided.
`99203`	Office or other outpatient visit for the evaluation and management of a new patient, typically 30 minutes	Used when a new patient presents for evaluation of BPH or hair loss and finasteride is initiated.
`80053`	Comprehensive metabolic panel (CMP)	Lab testing occasionally obtained prior to or during medication therapy to monitor baseline metabolic status per clinician judgment.
`84153`	Prostate specific antigen (PSA)	Often ordered as part of baseline evaluation for BPH prior to initiating finasteride.
`36415`	Collection of venous blood by venipuncture	Performed when labs such as PSA or CMP are ordered in association with initiation or monitoring of finasteride.