G0121 HCPCS code: Colorectal cancer screening; colonoscopy on individual not meeting criteria for high risk
G0121 is the HCPCS Level II code for colorectal cancer screening; colonoscopy on individual not meeting criteria for high risk. In 2024 Medicare paid an average of $275.24 per service for G0121 across 301,611 services. Its Medicare coverage code is D (Special coverage instructions apply): Medicare covers it when its national or local coverage criteria are met. The NCCI unit limit is 1 per day on outpatient hospital claims. Medicare volume rose 6% from 2022 to 2024 (283,930 to 301,611 services). In 2024, about 21,574 clinicians billed Medicare for G0121 for 218,751 beneficiaries; California, Florida, Texas accounted for 26% of services.
Code details
| Field | Value |
|---|---|
| Section | G codes — Procedures and professional services (temporary) |
| Coverage code | D — Special coverage instructions apply |
| Pricing indicator | 11 — Priced using national relative value units (Physician Fee Schedule) |
| BETOS category | P8D |
| Added | 1998-01-01 |
| Last action effective | 2024-01-01 |
Who bills G0121 (2024)
| Measure | Value |
|---|---|
| Clinicians billing (by place of service) | 21,574 |
| Medicare beneficiaries | 218,751 |
| States with claims | 55 |
| Share of services in top 3 states (California, Florida, Texas) | 26% |
Counts only. Supplier and clinician names, contact lists and state-by-state detail are in Caduvo.
Medicare utilization for G0121, 2022–2024
| Year | Services | Beneficiaries | Avg. allowed | Avg. paid |
|---|---|---|---|---|
| 2022 | 283,930 | 205,349 | $246.67 | $246.67 |
| 2023 | 304,855 | 220,475 | $262.36 | $262.36 |
| 2024 | 301,611 | 218,751 | $275.24 | $275.24 |
States with the most G0121 services (2024)
| State | Services | Avg. paid |
|---|---|---|
| California | 30,909 | $344.96 |
| Florida | 25,686 | $285.40 |
| Texas | 23,131 | $276.40 |
| Pennsylvania | 14,451 | $260.30 |
| Ohio | 12,037 | $237.18 |
NCCI unit limits (MUE)
| Claim type | Max units per day | Rationale |
|---|---|---|
| outpatient hospital claims | 1 | Anatomic Consideration |
| practitioner claims | 1 | Anatomic Consideration |
Medicare policy articles for this code
- A55227: Billing and Coding: Incomplete Colonoscopy/Failed Colonoscopy (Palmetto GBA (MAC - Part A, MAC - Part B))
Covered diagnoses (3 ICD-10-CM codes)
The diagnoses most often listed as covered in the policy articles above:
| ICD-10-CM | Diagnosis | Articles listing it |
|---|---|---|
| Z12.11 | Encounter for screening for malignant neoplasm of colon | 1 |
| Z15.060 | Genetic susceptibility to colorectal cancer | 1 |
| Z80.0 | Family history of malignant neoplasm of digestive organs | 1 |
What changed for G0121
- 1998-01-01: G0121 added to HCPCS Level II
- Next scheduled CMS quarterly update (HCPCS and DMEPOS fee schedule): 2027-01-01
Frequently asked questions
What is HCPCS code G0121?
G0121 is the HCPCS Level II code for colorectal cancer screening; colonoscopy on individual not meeting criteria for high risk. Short descriptor: "Colon ca scrn not hi rsk ind".
How much does Medicare pay for G0121?
In 2024, the average Medicare payment was $275.24 per service (average allowed $275.24).
Does Medicare cover G0121?
Coverage code D — Special coverage instructions apply. Medicare covers it when its national or local coverage criteria are met.
Which diagnoses support coverage for G0121?
Medicare policy articles that cite G0121 list 3 covered ICD-10-CM diagnosis codes across 1 article. The most cited include Z12.11 (Encounter for screening for malignant neoplasm of colon), Z15.060 (Genetic susceptibility to colorectal cancer), Z80.0 (Family history of malignant neoplasm of digestive organs). A listed diagnosis is necessary but not sufficient; the policy's other criteria still apply.
How many units of G0121 can be billed per day?
1 on outpatient hospital claims; 1 on practitioner claims (NCCI medically unlikely edits).
Related G01 codes
- G0101 — Cervical or vaginal cancer screening; pelvic and clinical breast examination
- G0102 — Prostate cancer screening; digital rectal examination
- G0103 — Prostate cancer screening; prostate specific antigen test (PSA)
- G0104 — Colorectal cancer screening; flexible sigmoidoscopy
- G0105 — Colorectal cancer screening; colonoscopy on individual at high risk
- G0106 — Colorectal cancer screening; alternative to g0104, screening sigmoidoscopy, barium enema
- G0108 — Diabetes outpatient self-management training services, individual, per 30 minutes
- G0109 — Diabetes outpatient self-management training services, group session (2 or more), per 30 minutes
- G0117 — Glaucoma screening for high risk patients furnished by an optometrist or ophthalmologist
- G0118 — Glaucoma screening for high risk patient furnished under the direct supervision of an optometrist or ophthalmologist
- G0120 — Colorectal cancer screening; alternative to g0105, screening colonoscopy, barium enema.
- G0122 — Colorectal cancer screening; barium enema
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Next steps
- Run a reimbursement report for a device billed under G0121
- Watch G0121 for fee, coverage and descriptor changes
- Build a full Medicare revenue model for G0121
Sources: CMS HCPCS Level II release October 2026; CMS DMEPOS fee schedule; CMS NCCI MUE tables; CMS Medicare utilization (physician and DME supplier files); CMS Medicare Coverage Database articles. Fees are Medicare allowables, not commercial rates. Not billing or legal advice.