Key facts for G0121
- Medicare payment
- $378.43
- PFS non-facility, national; facility $165.00
- Coverage code
- D
- special coverage instructions apply
- Practitioner MUE
- 1
- MAI 2
- NCCI PTP pairs
- 327
- 296 hospital outpatient
- LCDs and articles
- 1 / 1
TL;DR
G0121 is a Level II code from the G section (procedures and professional services, temporary), in use since 1998: "Colorectal cancer screening; colonoscopy on individual not meeting criteria for high risk". National PFS payment for G0121 is $378.43 in an office and $165.00 in a facility (October 2026), built from 3.18 work, 7.73 practice-expense and 0.42 malpractice RVUs at $33.4009 per RVU. Qualifying APM participants get $380.32 at $33.5675. Global period 000 (0-day global period). CMS caps G0121 at practitioner 1 (MAI 2, Anatomic Consideration); hospital outpatient 1 (MAI 2, Anatomic Consideration) units per day in the 2026 Q4 MUE tables. G0121 is a primary code for 1 add-on code (G0513). In the NCCI PTP files v323r0 G0121 appears in 19 practitioner pairs as column 2 and 308 as column 1 (most often with 0885T, 0886T, 45349), and in 19 hospital outpatient pairs as column 2 and 277 as column 1. 1 active LCD and 1 billing and coding article list G0121 across 4 states: L34454 (Colonoscopy/Sigmoidoscopy/Proctosigmoidoscopy), A55227. HCPCS record: BETOS P8D (endoscopy - colonoscopy); pricing indicator 11; type of service 2 (surgery). 4 other active codes open with "Colorectal cancer screening"; related codes: G0105, G0104, G0327, G0328.
G0121 descriptor and code status
The October 2026 HCPCS Level II file describes G0121 as “Colorectal cancer screening; colonoscopy on individual not meeting criteria for high risk”. It sits in the G section (procedures and professional services, temporary), listed with the other G codes. Although searches often call it the "G0121 CPT code", G0121 is a HCPCS Level II code maintained by CMS, not an AMA CPT code; both go in the same procedure-code field on the claim.
| Field | Value |
|---|---|
| Short descriptor | Colon ca scrn not hi rsk ind |
| Added to HCPCS | 1998-01-01 |
| Last action | N (no maintenance), effective 2024-01-01 |
| Coverage code | D: special coverage instructions apply |
| Pricing indicator | 11: physician fee schedule, priced with national RVUs |
| BETOS category | P8D: endoscopy - colonoscopy |
| Type of service | 2: surgery |
Medicare payment for G0121
National PFS payment for G0121 is $378.43 in an office and $165.00 in a facility (October 2026), built from 3.18 work, 7.73 practice-expense and 0.42 malpractice RVUs at $33.4009 per RVU. Qualifying APM participants get $380.32 at $33.5675. Global period 000 (0-day global period). The amounts below are national figures from the October 2026 CMS files; the contractor applies the locality, rural or state adjustment and the beneficiary's cost sharing.
Physician fee schedule (RVU26D)
Status A: active: paid separately under the physician fee schedule when covered. Global period 000 (0-day global period); PC/TC indicator 0 (physician service; the professional/technical split does not apply).
| Component | Non-facility | Facility |
|---|---|---|
| Work RVU | 3.18 | 3.18 |
| Practice expense RVU | 7.73 | 1.34 |
| Malpractice RVU | 0.42 | 0.42 |
| Total RVUs | 11.33 | 4.94 |
| National payment (CF $33.4009) | $378.43 | $165.00 |
| Qualifying APM participant (CF $33.5675) | $380.32 | $165.82 |
- Multiple procedures (modifier 51): standard multiple-procedure reduction (100%, then 50%)
- Bilateral (modifier 50): 150% bilateral adjustment does not apply
- Assistant at surgery: assistant at surgery may not be paid; co-surgeons: co-surgeons not permitted; team surgery: team surgeons not permitted
- Physician supervision of diagnostic procedures: supervision concept does not apply
G0121 also carries 53 rows in the RVU file, priced separately from the global service.
| Modifier | Status | Non-facility | Facility |
|---|---|---|---|
| 53 | A | $189.38 | $82.50 |
Hospital outpatient (OPPS Addendum B)
Status indicator T (Procedure or service, multiple reduction applies), APC 5311 (Level 1 Lower GI Procedures), national unadjusted payment $950.10 with a minimum unadjusted copayment of $0.00.
Ambulatory surgical center (Addendum AA)
Payment indicator A2 (Surgical procedure on ASC list in CY 2007; payment based on OPPS relative payment weight), national rate $510.49 at a payment weight of 9.0638. The multiple-procedure discount applies when it is billed with another ASC procedure.
Medically Unlikely Edits for G0121
CMS caps G0121 at practitioner 1 (MAI 2, Anatomic Consideration); hospital outpatient 1 (MAI 2, Anatomic Consideration) units per day in the 2026 Q4 MUE tables. The practitioner MUE is a date-of-service policy edit: units above the limit deny even when split across lines, and appeals rarely succeed.
| Setting | MUE (units/DOS) | MAI | CMS rationale |
|---|---|---|---|
| Practitioner services | 1 | 2 Date of Service Edit: Policy | Anatomic Consideration |
| Facility outpatient hospital | 1 | 2 Date of Service Edit: Policy | Anatomic Consideration |
The MUE lookup for G0121 shows every setting next to any other code on the same claim.
NCCI edits and add-on rules
In the practitioner PTP file v323r0, G0121 is the column-2 (bundled) code in 19 active pairs, 5% of which allow a modifier and the column-1 code in 308 (69% modifier-allowed); 224 earlier pairs have been deleted. CMS's most frequent rationale for the bundled pairs: Mutually exclusive procedures.
| Column-1 code | Pairs |
|---|---|
| 0885T (CPT; descriptor licensed by AMA) | 1 |
| 0886T (CPT; descriptor licensed by AMA) | 1 |
| 45349 (CPT; descriptor licensed by AMA) | 1 |
| 45378 (CPT; descriptor licensed by AMA) | 1 |
| 45379 (CPT; descriptor licensed by AMA) | 1 |
| 45380 (CPT; descriptor licensed by AMA) | 1 |
| 45381 (CPT; descriptor licensed by AMA) | 1 |
| 45382 (CPT; descriptor licensed by AMA) | 1 |
| Column-2 code | Pairs |
|---|---|
| 0091U (CPT; descriptor licensed by AMA) | 1 |
| 0163U (CPT; descriptor licensed by AMA) | 1 |
| 0213T (CPT; descriptor licensed by AMA) | 1 |
| 0216T (CPT; descriptor licensed by AMA) | 1 |
| 0405U (CPT; descriptor licensed by AMA) | 1 |
| 0421U (CPT; descriptor licensed by AMA) | 1 |
| 0460U (CPT; descriptor licensed by AMA) | 1 |
| 0461U (CPT; descriptor licensed by AMA) | 1 |
In the hospital outpatient PTP file v323r0, G0121 is the column-2 (bundled) code in 19 active pairs, 5% of which allow a modifier and the column-1 code in 277 (88% modifier-allowed); 178 earlier pairs have been deleted. CMS's most frequent rationale for the bundled pairs: Mutually exclusive procedures.
| Column-1 code | Pairs |
|---|---|
| 0885T (CPT; descriptor licensed by AMA) | 1 |
| 0886T (CPT; descriptor licensed by AMA) | 1 |
| 45349 (CPT; descriptor licensed by AMA) | 1 |
| 45378 (CPT; descriptor licensed by AMA) | 1 |
| 45379 (CPT; descriptor licensed by AMA) | 1 |
| 45380 (CPT; descriptor licensed by AMA) | 1 |
| 45381 (CPT; descriptor licensed by AMA) | 1 |
| 45382 (CPT; descriptor licensed by AMA) | 1 |
| Column-2 code | Pairs |
|---|---|
| 0091U (CPT; descriptor licensed by AMA) | 1 |
| 0163U (CPT; descriptor licensed by AMA) | 1 |
| 0213T (CPT; descriptor licensed by AMA) | 1 |
| 0216T (CPT; descriptor licensed by AMA) | 1 |
| 0405U (CPT; descriptor licensed by AMA) | 1 |
| 0421U (CPT; descriptor licensed by AMA) | 1 |
| 0460U (CPT; descriptor licensed by AMA) | 1 |
| 0461U (CPT; descriptor licensed by AMA) | 1 |
G0121 is a designated primary code for 1 add-on code (G0513).
Pair counts show exposure, not the answer for one claim. Check G0121 against a second code to see whether the pair bundles and whether a modifier can separate the services.
Medicare coverage policies for G0121
1 active Local Coverage Determination and 1 billing and coding article list G0121. Each applies only in its contractor's jurisdiction, and the article carries the diagnosis codes that support the item or service.
- Colonoscopy/Sigmoidoscopy/Proctosigmoidoscopy (L34454) · Palmetto GBA
| Article | Title | Contractor(s) | Related LCD |
|---|---|---|---|
| A55227 | Billing and Coding: Incomplete Colonoscopy/Failed Colonoscopy | Palmetto GBA | L34454 |
Denials to expect on G0121
the diagnosis or documentation does not meet the LCD or billing article that lists G0121
the modifier reported is inconsistent with the code
the claim lacks information needed to adjudicate the line, such as an order, NPI or required modifier
Where QuickIntell fits for G0121 claims
QuickCode supports qualified coder review of units, modifiers and NCCI pairs for G0121 before the claim leaves, and QuickRCM carries claim readiness and the denial follow-up when an edit or coverage policy is missed.
Frequently asked questions: HCPCS G0121
What does HCPCS code G0121 describe?
"Colorectal cancer screening; colonoscopy on individual not meeting criteria for high risk" (short descriptor "Colon ca scrn not hi rsk ind"), in the G section (procedures and professional services, temporary). Added 1998-01-01; last action N (no maintenance) effective 2024-01-01.
Is G0121 a CPT code?
It is not. G0121 belongs to the G section (procedures and professional services, temporary) of HCPCS Level II, the CMS code set, not to AMA CPT. "G0121 CPT code" searches refer to it.
What does Medicare pay for G0121?
National PFS payment for G0121 is $378.43 in an office and $165.00 in a facility (October 2026), built from 3.18 work, 7.73 practice-expense and 0.42 malpractice RVUs at $33.4009 per RVU. Qualifying APM participants get $380.32 at $33.5675. Global period 000 (0-day global period).
Is G0121 an add-on code?
G0121 is a primary code for 1 add-on code (G0513).
How many units of G0121 can be billed per day?
CMS caps G0121 at practitioner 1 (MAI 2, Anatomic Consideration); hospital outpatient 1 (MAI 2, Anatomic Consideration) units per day in the 2026 Q4 MUE tables. For the practitioner MUE (MAI 2), units above 1 deny for the whole day as a policy limit; denials arrive as CARC 151.
Does Medicare cover G0121?
Coverage code D (special coverage instructions apply). 1 active LCD and 1 billing and coding article list G0121 across 4 states: L34454 (Colonoscopy/Sigmoidoscopy/Proctosigmoidoscopy), A55227.
Sources
Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-10. Verify against the primary file before billing or contracting decisions. The reference methodology explains how each figure is computed from these files.
- HCPCS Level II alpha-numeric file, October 2026Version October 2026 · effective 2026-10-01 · file HCPC2026_OCT_ANWEB_09232026.txtSHA-256 c25240c63108756d…
- Medicare PFS national relative value file RVU26D (non-QPP), October 2026Version RVU26D, released 2026-08-26 · effective 2026-10-01 · file PPRRVU2026_Oct_nonQPP.csvSHA-256 4d0d3f19bd954ffc…
- Medicare PFS national relative value file RVU26D (qualifying APM participants), October 2026Version RVU26D, released 2026-08-26 · effective 2026-10-01 · file PPRRVU2026_Oct_QPP.csvSHA-256 59d3734704853936…
- OPPS Addendum B, October 2026Version October 2026 · effective 2026-10-01 · file 508-compliant-version-2026_October_Web_Addendum_B.09.28.26.csvSHA-256 6ad7393a318bf1b9…
- Integrated Outpatient Code Editor v27.3 data tables: status and payment indicatorsVersion I/OCE v27.3 (October 2026) · effective 2026-10-01 · file Data_Status_Indicator.txtSHA-256 78f119ef0a435351…
- ASC Addendum AA (covered surgical procedures), October 2026Version October 2026 · effective 2026-10-01 · file Oct 2026 ASC AA.txtSHA-256 bc3479589b7b1f23…
- NCCI MUE table, practitioner services, effective 2026-10-01Version 2026 Q4 · effective 2026-10-01 · file MCR_MUE_PractitionerServices_Eff_10-01-2026.csvSHA-256 ef038efaf902b7bd…
- NCCI MUE table, facility services, effective 2026-10-01Version 2026 Q4 · effective 2026-10-01 · file MCR_MUE_OutpatientHospitalServices_Eff_10-01-2026.csvSHA-256 3af9f4e99cc587e2…
- NCCI MUE table, dme services, effective 2026-10-01Version 2026 Q4 · effective 2026-10-01 · file MCR_MUE_DMESupplierServices_Eff_10-01-2026.csvSHA-256 6fa4fbba852f7b74…
- NCCI PTP edits, practitioner, v323r0 (four files)Version v323r0 (2026 Q4) · effective 2026-10-01 · file ccipra-v323r0-f1.TXTSHA-256 7793c0b6686c1e22…
- NCCI PTP edits, hospital outpatient, v323r0 (four files)Version v323r0 (2026 Q4) · effective 2026-10-01 · file ccioph-v323r0-f1.txtSHA-256 063f41b91ef9faa2…
- NCCI Add-On Code edits, effective 2026-10-01Version 2026 Q4 · effective 2026-10-01 · file AOC_V2026Q4-F-MCR.xlsxSHA-256 eabb519623134549…
- Medicare Coverage Database, current Billing and Coding Articles exportVersion MCD release 2026-10-08 · effective 2026-10-04 · file article.csvSHA-256 5e95c4a8ac3664be…
- Medicare Coverage Database, current LCD exportVersion MCD release 2026-10-08 · effective 2026-10-04 · file lcd.csvSHA-256 9aee1bd7f14056b0…
Disclaimer
This page is an operational reference compiled from CMS publications: the HCPCS Level II file, the physician, DMEPOS and clinical laboratory fee schedules, OPPS and ASC addenda, NCCI MUE, PTP and add-on edit tables and the Medicare Coverage Database. Amounts are Medicare national figures before locality and state adjustment; Medicaid and commercial payers set their own. CPT codes are shown as numbers only; CPT descriptors are copyright AMA. Nothing here is legal, clinical or billing advice.
Found a figure that does not match the CMS file? Report a data correction with the CMS file and the value you expected; the request reaches the editorial team through the contact form.