How much does Medicare pay for CPT 45331?

Medicare allowed an average of $291.11 per service and paid $228.52 of that, the balance being the patient's coinsurance and deductible (2024 data). Providers submitted an average of $1501.56, which is what they billed rather than what they received — Medicare pays its fee schedule regardless of the charge.

What is CPT code 45331?

Biopsy of lower large bowel using a flexible endoscope. It was billed 6,680 times to 6,481 Medicare beneficiaries by 358 providers in 2024.

Does 45331 pay differently in an office than a hospital?

Yes. The allowed amount averaged $165.20 in an office setting and $300.77 in a facility. The office rate is generally higher because the practice supplies the room, staff and equipment out of that single payment; in a hospital those are billed separately by the facility.

Which specialty bills 45331 most?

Ambulatory Surgical Center, with 4,083 services from 199 clinicians. Next are Gastroenterology, Colorectal Surgery (Proctology), Internal Medicine.

CPT 45331

Biopsy of lower large bowel using a flexible endoscope

$291.11Medicare-allowed amount per service, averaged across 6,680 services

Providers submitted

$1501.56

Asking price, not received

Medicare allowed

$291.11

The fee schedule figure

Medicare paid

$228.52

Balance is patient coinsurance

Providers submitted an average of $1501.56 for this code and Medicare allowed $291.11 — 5.2× less. That gap is normal and means nothing on its own: Medicare pays its fee schedule regardless of what is billed, so the submitted figure describes a hospital chargemaster, not a price anyone paid. Of the allowed amount Medicare paid $228.52 (78%); the rest is the patient’s coinsurance and deductible.

Office pays differently to hospital

Office / non-facility: $165.20
Hospital / facility: $300.77

The facility rate is higher for this code, which is unusual and generally means the service depends on equipment or staffing a hospital carries. 476 services were billed in an office setting and 6,204 in a facility.

Services: 6,680
Beneficiaries: 6,481
Providers billing it: 358
Total allowed: $1,944,615

What Medicare pays for CPT 45331

Across 6,680 services billed by 358 providers to 6,481 beneficiaries, Medicare allowed an average of $291.11 per service. The allowed amount is the figure that matters: it is what Medicare and the patient together owe, set by the fee schedule and adjusted for local practice costs. What a provider chose to submit has no bearing on it.

Who bills 45331

Specialty	Services	Beneficiaries	Avg allowed	Providers
Ambulatory Surgical Center	4,083	3,978	$426.21	199
Gastroenterology	2,012	1,974	$74.66	128
Colorectal Surgery (Proctology)	379	334	$92.88	19
Internal Medicine	110	105	$98.68	7
Surgical Oncology	51	45	$79.63	2
Emergency Medicine	19	19	$27.26	1
General Surgery	15	15	$68.99	1
Physician Assistant	11	11	$228.92	1

45331 reimbursement by state

Two different numbers. Allowed is what Medicare actually allowed in that state, which includes the local practice-cost adjustment. Standardized strips that geographic adjustment out of the payment, so it is the column to use when comparing states — a difference there reflects how the code was billed, not what it costs to run a practice locally.

State	Services	Allowed	Standardized pmt	Providers
Florida	1,039	$272.27	$226.00	56
New York	592	$297.03	$204.29	26
California	548	$303.24	$194.90	36
Tennessee	478	$241.19	$210.07	16
Texas	399	$296.05	$246.69	24
Arizona	373	$255.14	$205.60	21
Louisiana	370	$225.84	$199.75	15
Mississippi	332	$263.82	$238.76	12
Maryland	244	$406.12	$325.09	13
North Carolina	236	$298.44	$250.66	11
South Carolina	218	$244.10	$207.89	12
New Jersey	196	$408.92	$301.81	12
Illinois	164	$364.29	$298.11	11
Ohio	152	$405.87	$345.64	11
Pennsylvania	127	$398.99	$333.72	9
Massachusetts	113	$68.61	$48.62	8
Alabama	95	$242.54	$220.44	5
Indiana	90	$266.43	$215.55	5
Arkansas	83	$286.10	$241.71	5
Minnesota	83	$400.46	$306.73	3
New Mexico	81	$333.15	$285.98	3
Georgia	67	$290.97	$237.80	5
Missouri	61	$363.60	$290.82	4
Washington	54	$373.69	$276.78	4
Colorado	50	$454.42	$364.38	3
Nevada	48	$285.86	$211.40	2
Virginia	45	$165.29	$130.99	3
Iowa	37	$394.59	$323.25	2
Kentucky	36	$427.03	$356.12	2
Oregon	31	$258.97	$178.48	2
Michigan	29	$428.17	$347.96	2
Connecticut	28	$258.16	$214.39	2
Montana	27	$214.94	$163.58	2
Wisconsin	25	$251.08	$193.27	2
Nebraska	19	$408.83	$312.59	1
Maine	18	$447.23	$370.52	1
Kansas	17	$56.87	$45.13	1
Idaho	14	$381.46	$320.23	1
New Hampshire	13	$60.95	$43.75	1
Oklahoma	13	$58.93	$52.11	1
Alaska	12	$71.84	$43.58	1
Delaware	12	$459.02	$349.59	1
South Dakota	11	$67.18	$51.11	1

Related codes

45385Removal of polyps or growths of large bowel$362.33
45380Biopsy of large bowel$242.88
45378Diagnostic exam of large bowel$260.72
45384Removal of polyps or growths of large bowel$277.07
45381Injection beneath lining of large bowel$181.72
45390Removal of large bowel tissue$582.65
45330Diagnostic exam of lower portion of large bowel$98.83
45388Destruction of polyp or growth of large bowel$491.91
45300Diagnostic exam of rectum and lower large bowel$116.96
45382Control of bleeding of upper large bowel$290.18
45398Banding of hemorrhoids$404.14

Billing this code is not the same as earning it

An allowed amount is revenue to a practice, not income to a clinician. It funds staff, premises, equipment and supplies before anyone is paid. What clinicians actually earn is published separately by the Department of Labor, and what industry pays them is published separately again by CMS — this site carries both.

What doctors are paid →·Look up a clinician →·All procedure codes →

Where this comes from. CMS Medicare Physician & Other Practitioners, by Provider and Service, 2024. It covers fee-for-service Original Medicare Part B only — not Medicare Advantage, not Medicaid, and not commercial insurance, which typically pays more for the same code.

How it is averaged. CMS publishes one average per provider per code. Every figure here is re-weighted by the number of services, so a clinician who billed the code 4,000 times counts 4,000 times more than one who billed it twice. CMS also suppresses any provider-code pair with fewer than 11 beneficiaries, so low-volume practice is missing from these totals by design.