How to Code Screening and Diagnostic Colonoscopy

by  Natalie Tornese, CPC
February 1st, 2018

The following information is from BC Advantage.
Colonoscopy is a common procedure performed by by Gastroenterologists. CPT defines a colonoscopy examination as "the examination of the entire colon, from the rectum to the cecum or colon-small intestine anastomosis, and may include an examination of the terminal ileum or small intestine proximal to an anastomosis" as well. Coding for screening colonoscopies and assigning modifiers can be challenging for providers. To report services correctly, physicians and medical coding service providers need to understand the difference between diagnostic and screening colonoscopy, and surveillance colonoscopy, which is a subset of screening.
Diagnostic and Screening Colonoscopy
Reporting a Screening Colonoscopy
The following ICD-10 codes are used to report a screening colonoscopy:
Point to note: An article published in the Bulletin of the American College of Surgeons on May 1, 2016 instructs that if a polyp is discovered and removed during the same procedure, these ICD-10 codes should still be reported as the primary diagnosis codes, followed by the appropriate ICD-10 code for polyp: D12.0-D12.9 (benign neoplasm of the colon or rectum, based on location).
ICD-10 Codes associated with National Coverage Determination (NCD) for Colorectal Cancer Screening Tests
D12.6 - Benign neoplasm of colon, unspecified
K50 family - Crohn's disease
K51 family - Ulcerative (chronic) proctitis
K52.1 - Toxic gastroenteritis and colitis
K52.89 - Other specified noninfective gastroenteritis and colitis
K52.9 - Noninfective gastroenteritis and colitis, unspecified
Z12.11 - Encounter for screening for malignant neoplasm of colon
Z12.12 - Encounter for screening for malignant neoplasm of rectum
Z15.09 - Genetic susceptibility to other malignant neoplasm
Z80.0 - Family history of malignant neoplasm of digestive organs
Z83.71 - Family history of colonic polyps
Z85.038 - Personal history of other malignant neoplasm of large intestine
Z85.048 - Personal history of other malignant neoplasm of rectum, rectosigmoid junction, and anus
Z86.010 Personal history of colonic polyps
Screening and Surveillance Colonoscopy
Many providers are unsure about a screening and surveillance colonoscopy and how it should be coded for an asymptomatic patient. A article explains:
Different Codes for Medicare and Other Payers
The codes for reporting colonoscopies differ between Medicare and other payers. CPT codes are used to report colonoscopy to non-Medicare payers.

Non-Medicare payers
• If the patient is under a commercial plan, exchange plan or Medicaid, report colonoscopy using CPT codes45378-45398
45378 Colonoscopy
45379 Foreign body(s) removal
45380 Biopsy
45381 Submucosal injection
45382 Control of bleeding
45384 Hot biopsy
45385 Snare
45386 Dilation
45388 Ablation
45389 Stent placement
45391 Endoscopic ultrasound
45392 Endoscopic ultrasound with FNA
45390 Endoscopic mucosal resection (EMR)
45398 Band ligation
Point to note: Code 45378 is the base code for a colonoscopy without biopsy or other interventions. It includes brushings or washings if performed. Report 45378 with ICD-10 code Z86.010 on the first line of the CMS 1500 form.

• If the procedure is performed through a stoma rather than the anus, report 44388-44408:
44388 Colonoscopy through stoma
44389 Biopsy
44390 Foreign body(s) removal
44391 Control of bleeding
44392 Hot biopsy
44401 Ablation
44394 Snare
44402 Stent placement
44403 Endoscopic mucosal resection (EMR)
44404 Submucosal injection
44405 Balloon dilation
44406 Endoscopic ultrasound
44407 Endoscopic ultrasound (EUS) with FNA
44408 Decompression
Medicare payers
Medicare beneficiaries without high-risk factors are eligible for a  screening colonoscopy every ten years. Beneficiaries at higher risk for developing colorectal cancer are eligible for screening once every 24 months. Medicare considers an individual who is at high risk of developing colorectal cancer as one who has one or more of the following:
For Medicare beneficiaries, screening colonoscopy is reported using the following HCPCS codes:
G0105 (Colorectal cancer screening; colonoscopy on individual at high risk), for a Medicare beneficiary at high risk for colorectal cancer, and the appropriate diagnosis code that necessitates the more frequent screening.
G0121 (Colorectal cancer screening; colonoscopy on individual not meeting the criteria for high risk) and Z12.11 (Encounter for screening for malignant neoplasm of colon) or Z12.12 (Encounter for screening for malignant neoplasm of the rectum) as appropriate.
Modifiers for Colonoscopy
Reimbursement Issues
For the calendar year (CY) 2017, CMS separated moderate sedation services from the majority of GI endoscopy procedures under Medicare Part B.
As a result:
- This move has no impact on gastroenterologists performing their own moderate sedation for endoscopic procedures. Beginning January 2017, they now report two codes instead of one - the procedure code and the proposed moderate sedation code.
- For gastroenterologists who use anesthesia professionals, the value of the majority of all GI endoscopy procedures has been reduced by 0.10 RVUs.
According to a study by the American Cancer Society, 90% colorectal cancer (CRC) cases are detected in individuals with over 50 years in the U.S and colonoscopy is the most effective and the most commonly adopted procedure for the diagnosis and screening of CRC in older adults. With complex coding and reimbursement challenges, providers would do well to partner with an experienced medical billing and coding company to ensure error-free claim submission for appropriate payment. 


How to Code Screening and Diagnostic Colonoscopy. (2018, February 1). Find-A-Code Articles. Retrieved from

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