CurrentColorado Rocky Mountain Health PlansPolicy N/A

Outpatient therapy billing (PT/OT/SLP) revenue codes and modifiers

Defines requirements for reporting outpatient PT, OT, and speech-language pathology services on UB04 or electronic equivalent for all products and network/non-network outpatient hospital claims.

Policy Summary

PayerColorado Rocky Mountain Health Plans

PolicyOutpatient therapy billing (PT/OT/SLP) revenue codes and modifiers

Policy CodePolicy N/A

Change TypeNo material changes

Effective DateN/A

Next Review DateOct 1, 2025

Key ActionSubmit therapy services with appropriate CPT/HCPCS code, therapy revenue code (042x, 043x, 044x), and exactly one discipline modifier (GN, GO, or GP) per service line when under a plan of care.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

042x/043x/044xtherapy revenue code families required

GN, GO, GPmodifiers referenced

Only onemodifier per line

All productsapplies to

Listedstate exceptions

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Submission Criteria for Outpatient Therapy Services

Submission criteria for therapy services

Requirements when submitting outpatient therapy services under a plan of care:

Therapy services must be submitted with the appropriate CPT or HCPCS code for the services provided.

Therapy services must be submitted with the appropriate therapy revenue code: 042x (physical therapy), 043x (occupational therapy), or 044x (speech-language pathology).

A discipline modifier (GN, GO, or GP) must be submitted to distinguish the plan-of-care discipline in addition to the revenue code.

Only one of GN, GO, or GP may be reported on the same service line.

Revenue code and modifier combinations must match discipline: 042x lines may only contain GP; 043x lines may only contain GO; 044x lines may only contain GN.

Discipline-specific evaluation and re-evaluation service codes must be reported with the modifier for the associated discipline (for example, PT evaluation codes reported with modifier GP).

Policy applies to services reported on the UB04 claim form or its electronic equivalent for all products and outpatient hospital claims (note: some states are listed as exceptions).

See state exceptions in policy (e.g., North Carolina).

Required Revenue Codes, Modifiers, and Line-level Rules

Required revenue codes and discipline modifiersmixedCovered

042x	Physical therapy revenue code family
043x	Occupational therapy revenue code family
044x	Speech-language pathology revenue code family
GP	Modifier for physical therapy plan of care
GO	Modifier for occupational therapy plan of care
GN	Modifier for speech-language pathology plan of care

Modifier per line — Only one of GN/GO/GP allowed per service line

Modifier per service lineOnly one of GN, GO, or GP is allowed on the same service line.

PurposeDesignates which therapy plan of care (PT/OT/SLP) applies to the billed service line.

EnforcementCombinations of GN/GO/GP on a single line are not permitted; claims with multiple discipline modifiers on one line should be corrected.

Billing and Submission Requirements — Provider Responsibilities

Billing Rule

Billing requirements for outpatient therapy services

Submit outpatient therapy services billed on UB04 (or electronic equivalent) using the appropriate CPT/HCPCS service code, the applicable therapy revenue code (042x for physical therapy, 043x for occupational therapy, or 044x for speech-language pathology), and include exactly one plan-of-care discipline modifier (GN, GO, or GP) per service line to identify the discipline.

Use revenue code 042x lines only with modifier GP (physical therapy).
Use revenue code 043x lines only with modifier GO (occupational therapy).
Use revenue code 044x lines only with modifier GN (speech‑language pathology).
Only one of GN, GO, or GP may be reported on the same service line.

Definitions and Modifier Mapping

Therapy services performed by a qualified therapist under a certified plan of care

DefinitionTherapy services performed by a qualified therapist under a certified plan of care ("Always Therapy").

Submission requirementsSubmit with appropriate CPT/HCPCS code and therapy revenue code (042x, 043x, or 044x).

Modifier useWhen under a plan of care, append the discipline modifier that corresponds to the plan (GN, GO, or GP).

Therapy services performed by a physician or non-physician practitioner outside of a certified therapy plan of care

DefinitionTherapy services performed by a physician or non-physician practitioner outside of a certified therapy plan of care ("Sometimes Therapy").

Modifier guidanceDo not append GN/GO/GP for services not performed under a certified plan of care; these modifiers refer only to services provided under a plan of care.