Coding FAQ - Screening Colonoscopy

A screening test is a test provided to a patient in the absence of signs or symptoms. A screening colonoscopy is a service performed on an asymptomatic person for the purpose of testing for the presence of colorectal cancer or colorectal polyps. Whether a polyp or cancer is ultimately found does not change the screening intent of that procedure. As part of the Affordable Care Act (ACA), Medicare and most third-party payors are required to cover services given an A or B rating by the U.S. Preventive Services Task Force (USPSTF) without a co-pay or deductible, but the correct CPT and ICD-10-CM codes must be submitted to trigger coverage at 100% for the patient. See the AGA coding guide for CRC screening to learn what codes to use and know what patients can usually expect to pay depending on whether they have commercial insurance or Original Medicare.

Diagnostic colonoscopy is a test performed as a result of an abnormal finding, sign or symptom (such as abdominal pain, bleeding, diarrhea, etc.). Medicare and most commercial payors do not waive the co-pay and deductible when the intent of the visit is to perform a diagnostic colonoscopy.

For commercial and Medicaid patients, use CPT code 45378 (Colonoscopy, flexible, proximal to splenic flexure; diagnostic, with or without collection of specimen(s) by brushing or washing, with or without colon decompression [separate procedure]). However, if polyps are removed use the appropriate CPT code below based on the removal technique:

• 45380 – Colonoscopy, flexible; with biopsy, single or multiple
• 45384 – Colonoscopy, flexible; with removal of tumor(s), polyp(s), or other lesion(s) by hot biopsy forceps
• 45385 – Colonoscopy, flexible; with removal of tumor(s), polyp(s), or other lesion(s) by snare technique
• 45388 – Colonoscopy, flexible; with ablation of tumor(s), polyp(s), or other lesion(s) (includes pre- and post-dilation and guide wire passage, when performed)

Add modifier 33 (preventive services) to each CPT code submitted on the claim. If modifier 33 is not added, the colonoscopy will not be recognized as a screening service and the patient will be inappropriately billed.

For Medicare beneficiaries who choose colonoscopy as their colorectal cancer screening, use Healthcare Common Procedural Coding System (HCPCS) code G0105 (Colorectal cancer screening; colonoscopy on individual at high risk) or G0121 (Colorectal cancer screening; colonoscopy on individual not meeting the criteria for high risk) as appropriate. CMS developed the HCPCS codes to differentiate between screening and diagnostic colonoscopies in the Medicare population. If polyps are removed, use the appropriate CPT code listed above and add modifier PT (colorectal cancer screening test; converted to diagnostic test or other procedure) to each CPT code for Medicare. If modifier PT is not added to the CPT code submitted on the Medicare claim, the colonoscopy with polypectomy will not be recognized as a screening service and the patient will be inappropriately billed.

See the AGA coding guide for CRC screening for more information.

For commercial and Medicaid patients who have a colonoscopy following a positive non-invasive CRC screening test, use modifier 33 with the appropriate colonoscopy code (e.g., 45378, 45380) based on the procedure(s) performed.

For Medicare beneficiaries who have a colonoscopy following a positive result for any of the following non-invasive stool-based CRC screening tests on or after 1/1/2023, use the appropriate HCPCS codes G0105 or G0121 with the KX modifier.

• Screening guaiac-based fecal occult blood test (gFOBT) (CPT 82270)
• Screening immunoassay-based fecal occult blood test (iFOBT) (HCPCS G0328)
• Cologuard™ – multi-target stool DNA (sDNA) test (CPT 81528)

If modifier KX is not added to G0105 or G0121 for colonoscopy following a positive non-invasive stool-based test, Medicare will return the screening colonoscopy claim as “unprocessable.” If this happens, add modifier KX and resubmit the claim.

If polyps are removed during a screening colonoscopy for a Medicare patient, use the appropriate CPT code (45380, 45384, 45385, 45388) and add modifier PT (colorectal cancer screening test; converted to diagnostic test or other procedure) to each CPT code. However, it is important to note that if a polyp is removed during a screening colonoscopy, the Medicare beneficiary is responsible for 15% of the cost from 2023 to 2026. This falls to 10% of the cost from 2027 to 2029, and by 2030 it will be covered 100% by Medicare. Some Medicare beneficiaries are not aware that Medicare has not fully eliminated the coinsurance responsibility yet.

Medicare beneficiaries without high risk factors are eligible for screening colonoscopy every 10 years. Beneficiaries at high risk for developing colorectal cancer are eligible once every 24 months. Medicare considers an individual at high risk for developing colorectal cancer as one who has one or more of the following:

• A close relative (sibling, parent or child) who has had colorectal cancer or an adenomatous polyp.
• A family history of familial adenomatous polyposis.
• A family history of hereditary nonpolyposis colorectal cancer.
• A personal history of adenomatous polyps.
• A personal history of colorectal cancer.
• Inflammatory bowel disease, including Crohn’s disease and ulcerative colitis.

To report screening colonoscopy on a patient not considered high risk for colorectal cancer, use HCPCS code G0121 and diagnosis code V76.51 (Special screening for malignant neoplasm of the colon).

To report screening on a Medicare beneficiary at high risk for colorectal cancer, use HCPCS G0105 and the appropriate diagnosis code that necessitates the more frequent screening.

Here are some examples for screening colonoscopy, which applies to both the physician and outpatient facility. Claims should be coded the same for procedures, modifiers and diagnosis with the exception of the discontinued procedure modifier (when the physician uses modifier 53, the outpatient hospital/ambulatory surgical facility uses modifier 74).

Example #1
Indication: Colon screening
Post-endoscopy finding: Normal colonic mucosa
Procedure code: G0121 (Average risk screening) for Medicare or 45378-33 (Diagnostic colonoscopy with modifier 33 indicating this is a preventive service) for commercial insurance
Diagnosis code: V76.51 (Special screening for malignant neoplasms, colon)

Example #2
Indication: Personal history of colon polyps, Colon screening
Post-endoscopy findings: Normal colonoscopy
Procedure code: G0105 (High risk screening) for Medicare or 45378-33 (Diagnostic colonoscopy with modifier 33 indicating this is a preventive service) for commercial insurance
Diagnosis code: V12.72 (Personal history of colon polyps)

Example #3
Indication: Colon screening
Post-endoscopy findings: Polyps in the cecum and sigmoid colon
Procedure: Colonoscopy with removal of cecal and sigmoid polyps by snare technique
Procedure code: 45385 (Colonoscopy with removal of polyp by snare)
Modifier PT (if Medicare patient) or Modifier 33 (if non-Medicare) should be added to indicate this was a preventive service and to trigger CRC screening benefits
Diagnosis code: V76.51 (Special screening for malignant neoplasms, colon). Some Medicare payors instruct to only use the finding since the PT modifier indicates it was done for screening.
211.3 (Benign neoplasm, colon [based on pathology report])

Example #4
Indication: Personal history of colon polyps; Colon screening
Post-endoscopy findings: Large sessile polyp in the rectum, unable to resect, pending pathology
Procedure: Colonoscopy with biopsy of rectal polyp. Will await pathology and consider surgical referral.
Procedure code: 45380 (Colonoscopy with biopsy)
Modifier PT (if Medicare) or Modifier 33 (non-Medicare) should be added to indicate this was a preventive service and to trigger CRC screening benefits
Diagnosis code: V12.72 (Personal history of colon polyps). Some Medicare payors [e.g., First Coast and Noridian] instruct to only use the finding since the PT modifier indicates it was done for screening so check with the patient’s insurance for payor-specific rules.
211.4 (Benign neoplasm, rectum) or 235.2 (Neoplasm uncertain behavior, intestines and rectum [based on pathology report]).

Example #5
Indication: Change in bowel habits, presenting for colon screening
Post-endoscopy findings: Normal colon
Procedure: Colonoscopy
Procedure code: 45378
Do not append modifier 33 or PT, as this service was performed for a diagnostic, not screening, indication.

A visit prior to a screening colonoscopy for a healthy patient is not billable.

Yes. If the patient requires some intervention on the part of the gastroenterologist prior to the procedure, you can bill a New Patient or Established Patient visit, depending on whether the patient has received any face-to-face service by any provider of the same specialty in your office within the last three years.

No. Per Medicare guidelines, the procedure should be codes as a colonoscopy with a 53 modifier, which will pay a partial fee and allow you to repeat the procedure within the restricted time period and get full payment for the second procedure. Even if the scope was advanced beyond the splenic flexure, but the visualization was poor and the physician wants to repeat the procedure within the restricted time period, add the 53 modifier.

Yes. The time restrictions only apply between two screenings if the patient has no symptoms. Medicare does require cost-sharing for diagnostic colonoscopy and will be responsible for a portion of the bill.

Given Medicare’s time restriction of two years between two high risk screenings and 10 years between two average risk procedures, if a screening is repeated in one year, it will be denied by Medicare as “not medically necessary.” If the physician wants to repeat the procedure within the restricted time, the first procedure should be billed with a 53 modifier, even though the scope advanced beyond the splenic flexure.