Summary & Overview

HCPCS G4031: Radiation Oncology MIPS Specialty Set

HCPCS Level II code G4031 identifies the radiation oncology MIPS specialty set used for performance reporting within radiation therapy practices. As a specialty reporting code, it relates to quality measurement and program attestation rather than a discrete clinical procedure. Nationally, codes that support MIPS reporting influence provider performance tracking, payer value-based arrangements, and public quality reporting. Key payers typically involved in evaluations of MIPS-related reporting and value programs include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.

Readers will learn what G4031 represents, why it matters for radiation oncology practices, and how it fits into national value-based and quality-reporting frameworks. The publication outlines benchmarks and reporting expectations where available, summarizes relevant policy updates affecting MIPS specialty measures, and provides clinical context for radiation oncology practices regarding program participation. Data not available in the input will be clearly noted where applicable.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareG4031HCPCS Level IIradiation oncologyMIPSquality reportingvalue-based careoncology services

Billing Code Overview

HCPCS Level II code G4031 represents the Radiation oncology MIPS specialty set. This code corresponds to services and reporting elements tied to radiation oncology practice for Merit-based Incentive Payment System (MIPS) performance measurement.

Service type: Radiation oncology performance reporting and quality measure set
Typical site of service: Oncology clinics and radiation therapy centers, including hospital outpatient departments and freestanding radiation therapy facilities

Data not available in the input.

Clinical & Coding Specifications

Clinical Context

A typical patient is an adult with a confirmed or suspected malignancy referred to radiation oncology for treatment planning and quality reporting under the Merit-based Incentive Payment System (MIPS) specialty set. The workflow begins with the treating radiation oncologist evaluating the patient, reviewing diagnostic imaging and pathology, and documenting the treatment intent (curative, adjuvant, palliative). The patient undergoes simulation (CT simulation with immobilization), target and organ-at-risk delineation, dosimetry planning, and peer-review processes. Relevant team members include the radiation oncologist, medical physicist, dosimetrist, and radiation therapists. The G4031 code represents reporting within the radiation oncology MIPS specialty set and is used when clinicians submit quality measures and related documentation data elements for performance reporting. Typical sites of service are outpatient hospital-based radiation oncology departments or freestanding radiation therapy centers where simulation, planning, and fractionated treatment delivery occur. A realistic scenario: a 64-year-old patient with stage II non-small cell lung cancer seen in radiation oncology for definitive chemoradiation; the clinician documents all required MIPS specialty-set measures (e.g., treatment intent, baseline patient-reported outcomes, appropriate imaging) and submits the specialty set data elements associated with G4031 for performance reporting.

Coding Specifications

Modifier	Description	When to Use
`22`	Increased procedural services	Use when work or time substantially exceeds typical radiation oncology documentation or planning complexity beyond standard expectations.
`23`	Unusual anesthesia	Use when general anesthesia is required for simulation or treatment delivery in an unusual circumstance.
`52`	Reduced services	Use when portions of the radiation oncology service or reporting elements are partially reduced or omitted.
`53`	Discontinued procedure	Use when simulation or a scheduled treatment session is started but discontinued for documented medical reasons.
`54`	Surgical care only	Use when only the surgical portion is billed by a surgeon (rarely applicable; included for completeness when multidisciplinary billing occurs).
`55`	Postoperative care only	Use when only post-treatment follow-up care is furnished and billed by a provider distinct from the treating radiation oncologist.
`56`	Preoperative care only	Use when only pre-procedure evaluation or planning is billed separately from the actual radiation service.
`62`	Two surgeons	Use when two physicians share substantial treatment planning or procedural responsibilities and reporting rules permit shared billing.
`AS`	Non‑participating anesthesiologist	Use when an anesthesiologist who does not participate in a specific payer’s network provides anesthesia for simulation or treatment.
`CO`	Service provided under direction of a comprehensive care organization	Use when the radiation oncology service or reporting is performed under a contract with a Comprehensive Care Organization.
`CQ`	Service furnished by a therapist under an alternative payment demonstration	Use when applicable under demonstration projects related to advanced practice providers or therapists.
`FX`	Modifying factor for reduction in services — fracture care	Use when care relates to fracture management that affects radiation planning or delivery.
`FY`	Return to provider for administrative reasons	Use when a claim is returned or adjusted for administrative reasons affecting reporting.
`QK`	Medical direction of two, three, or four concurrent anesthesia procedures involving qualified individuals	Use when the radiation service required anesthesia with physician medical direction meeting concurrency rules.
`QX`	CRNA service with medical direction	Use when a certified registered nurse anesthetist provides anesthesia under medical direction for simulation or treatment.

Taxonomy Code	Specialty	Notes
207RG0300X	Radiation Oncology	Primary specialty responsible for treatment planning, simulation, and MIPS specialty-set reporting.
2083P0207X	Medical Physics	Physicists responsible for dosimetry, plan QA, and technical components of radiation delivery.
208D00000X	Radiation Therapist	Therapists who deliver fractionated radiation treatments and perform machine-specific tasks.
208600000X	Diagnostic Radiology	Radiologists who provide imaging interpretation used in planning and target delineation.
207L00000X	Hematology/Oncology	Medical oncologists involved in multidisciplinary care and coordination of chemoradiation workflows.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`C34.90`	Malignant neoplasm of unspecified part of unspecified bronchus or lung	Lung cancers commonly require radiation oncology MIPS reporting for definitive or palliative radiotherapy.
`C50.919`	Malignant neoplasm of unspecified site of unspecified female breast	Breast cancer is a frequent indication for radiation planning, delivery, and specialty-set quality reporting.
`C61`	Malignant neoplasm of prostate	Prostate cancer patients often undergo radiation therapy with detailed planning and MIPS documentation.
`C67.9`	Malignant neoplasm of bladder, unspecified	Bladder malignancies may require complex radiation planning and are included in radiation oncology quality measures.
`C00.9`	Malignant neoplasm of lip, unspecified	Head and neck cancers, including lip, are commonly treated with radiation requiring specialty-set reporting.
`C77.0`	Secondary and unspecified malignant neoplasm of lymph nodes of head, face and neck	Nodal disease often influences target delineation and is relevant to treatment planning and quality metrics.
`D63.0`	Anemia in neoplastic disease	Common comorbidity affecting tolerance and planning decisions documented in specialty-set measures.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`77261`	Therapeutic radiology simulation; complex	Performed prior to treatment planning to simulate patient position and immobilization for radiation delivery; commonly precedes MIPS reporting.
`77301`	Radiation treatment planning, simulation; simple or complex therapy planning (single field or simple 2D)	Dosimetry and physics planning activities that form the basis for the treatment plan associated with radiation oncology reporting.
`77336`	Continuing medical physics consultation, including assessment of treatment delivery and planning	Medical physicist oversight and plan evaluation linked to quality measures reported in the specialty set.
`77401`	Radiation treatment delivery, simple; per fraction	Represents delivery of a single fraction of radiation therapy; delivered after planning and relevant to outcome and quality reporting.
`77338`	Stereotactic radiation treatment delivery, per fraction	Used when stereotactic techniques are applied; relevant when specialty-set measures require documentation of advanced techniques.
`77427`	Radiation treatment management, 5 treatments	Management of radiation therapy over a course of care; often used in conjunction with documentation submitted within the MIPS specialty set.