CurrentMolina HealthcarePolicy N/A

Outpatient Therapy Reimbursement — Mandatory CMS Therapy Modifiers

Governs provider reimbursement requirements for outpatient rehabilitation therapy services and the mandatory use of CMS therapy modifiers (GP, GN, GO) for Molina Healthcare claims; affects providers billing Molina for PT, OT, and SLP services. Applies where state exceptions are noted in the document.

Policy Summary

PayerMolina Healthcare

PolicyOutpatient Therapy Reimbursement — Mandatory CMS Therapy Modifiers

Policy CodePolicy N/A

Change TypeNo material change

Effective DateN/A

Next Review DateN/A

Key ActionAppend the appropriate therapy modifier (GP, GN, GO) on all claims with outpatient rehabilitation HCPCS codes; if claim line space is insufficient, report additional modifiers in the remarks field.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

3therapy discipline modifiers required (GP, GN, GO)

alwaysalways therapy codes require modifier

denialsmissing/incorrect modifier consequence

may applystate exceptions

Modifier-based Coverage Criteria

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

Modifier-based coverage criteria

Reimbursement is contingent on correct reporting of therapy modifiers for outpatient rehabilitation services; missing or incorrect modifiers result in claim return or denial.

All claims containing an outpatient rehabilitation HCPCS code must include the appropriate therapy modifier to indicate the discipline of the plan of care (GP for physical therapy, GN for speech‑language pathology, GO for occupational therapy).

Therapy modifiers (GP, GN, GO) must be appended in accordance with CMS guidelines; providers may report these modifiers on claims in any order. If claim line space is insufficient for multiple modifiers, additional modifiers should be reported in the remarks field.

All 'always therapy' codes and services submitted with specialty codes 65, 67, or 15 are considered therapy and must include the correct therapy modifier (65 = PT in private practice, 67 = OT in private practice, 15 = SLP in private practice).

Claims for therapy services submitted without the correct therapy modifier for the applicable HCPCS code will be returned or denied (examples: denial of SLP without GN; denial of OT without GO; denial of PT without GP).

Required Modifiers and Codes

Required therapy modifiersModifierCovered

GP	Physical therapy (PT)
GN	Speech-language pathology (SLP)
GO	Occupational therapy (OT)

Related specialty codes (always therapy)ModifierCovered

65	Specialty code: physical therapist in private practice (always therapy)
67	Specialty code: occupational therapist in private practice (always therapy)
15	Specialty code: speech-language pathologist in private practice (always therapy)

Coding disclaimer

Scope of codesCodes listed in this policy are for reference only and may not be all-inclusive; deleted or not-yet-effective codes may be ineligible for reimbursement.

Coverage determinationListing of a service or device code does not guarantee coverage; coverage is determined by the member benefit document.

Coding standardsProviders and facilities must follow industry-standard coding practices (e.g., CPT®) when submitting claims.

Claim consequencesImproper billing and coding may result in Molina rejecting/denying the claim and seeking recovery of payments.

Policy updatesMolina reserves the right to revise the policy as industry practices change.

Billing and Modifier Reporting Requirements

Billing Rule

Modifier reporting requirements

All claims containing an outpatient rehabilitation HCPCS code must include the appropriate therapy modifier to indicate the discipline of the plan of care under which the service is delivered. The therapy modifiers are: GP (Physical therapy), GN (Speech-language pathology), and GO (Occupational therapy). These informational modifiers identify therapy services and must be appended in accordance with CMS guidelines. Providers may report these modifiers on claims in any order. If space on a claim line is insufficient for multiple modifiers, additional modifiers should be reported in the remarks field. Per CMS requirements, all 'always therapy' codes must include the correct therapy modifier. When a therapy code is submitted with specialty code 65 (physical therapist in private practice), 67 (occupational therapist in private practice), or 15 (speech-language pathologist in private practice), the service is always considered therapy and must have the appropriate modifier.

GP - Physical therapy (PT)
GN - Speech-language pathology (SLP)
GO - Occupational therapy (OT)

Denial Risk

Denial risk for missing modifiers

Claims for therapy services that do not include the correct therapy modifier for the applicable HCPCS code will be returned or denied. Examples: denial of speech-language pathology services billed without modifier GN; denial of occupational therapy services billed without modifier GO; denial of physical therapy services billed without modifier GP.

Key Terms

CMS definition

Agency nameCenters for Medicare & Medicaid Services (CMS), a federal entity within the U.S. Department of Health and Human Services.

Primary responsibilitiesOversees the Medicare program and collaborates with state governments to manage Medicaid and the Children’s Health Insurance Program (CHIP).

Regulatory roleInvolved in administration of health insurance portability regulations and federal oversight of related programs.

CPT definition

CPT definitionCurrent Procedural Terminology (CPT): used by physician offices, clinicians, and outpatient facilities to report the majority of procedures on claims.

Usage settingsUsed in physician offices, outpatient hospital facilities, outpatient dialysis centers, and ambulatory surgery centers.

Relation to HCPCSHCPCS (alphanumeric codes) are mandated by Medicare to report certain biologicals, drugs, devices, supplies, and services; CPT provides procedure-level reporting commonly used alongside HCPCS.

HCPCS definition

HCPCS purposeAlphanumeric HCPCS codes are mandated by Medicare to report various biologicals, drugs, devices, supplies, and certain services.

MandateMedicare requires providers to use HCPCS codes regardless of provider type when reporting the specified items and services.

Relationship to claimsHCPCS codes are utilized alongside CPT and modifiers to accurately report services on submitted claims.