CPT Coding for Follow-Up Colonoscopy After Positive Cologuard
For a follow-up colonoscopy after a positive Cologuard test, use CPT code 45378 (diagnostic colonoscopy) or the appropriate therapeutic colonoscopy code (45380-45385) if polyps are removed during the procedure.
Coding Framework
Diagnostic vs. Screening Classification
- A colonoscopy performed after a positive Cologuard is coded as a diagnostic procedure, not a screening procedure, because it is investigating an abnormal finding 1
- The positive Cologuard result changes the clinical indication from screening to diagnostic evaluation, which affects both CPT coding and insurance coverage 1
Primary CPT Codes to Use
- CPT 45378: Colonoscopy, flexible; diagnostic, including collection of specimen(s) by brushing or washing, when performed (separate procedure) - use this when no polyps are found or removed 1
- CPT 45380: Colonoscopy, flexible; with biopsy, single or multiple - use when biopsies are taken 1
- CPT 45385: Colonoscopy, flexible; with removal of tumor(s), polyp(s), or other lesion(s) by snare technique - use when polyps are removed by snare 1
- CPT 45384: Colonoscopy, flexible; with removal of tumor(s), polyp(s), or other lesion(s) by hot biopsy forceps - use when appropriate 1
Important Coding Considerations
Medicare Coverage
- For Medicare beneficiaries, the colonoscopy following a positive Cologuard should be billed as a diagnostic colonoscopy, not a screening colonoscopy 1
- Medicare typically covers diagnostic colonoscopies at 80% after the Part B deductible is met, whereas screening colonoscopies are covered at 100% with no cost-sharing 1
- The timing requirement is critical: colonoscopy should be performed within 6 months of the positive Cologuard to avoid increased risk of advanced-stage disease (adjusted OR 2.09,95% CI 1.43 to 3.06 for delays beyond 6 months) 2
Commercial Insurance
- Most commercial payers follow similar logic, treating the follow-up colonoscopy as diagnostic rather than screening 1
- Patient cost-sharing may apply for diagnostic procedures, unlike preventive screening colonoscopies which are typically covered at 100% under the Affordable Care Act 1
Common Coding Pitfalls to Avoid
Do Not Use Screening Codes
- Avoid CPT G0121 (screening colonoscopy for high-risk individuals) or CPT G0105 (screening colonoscopy for average-risk individuals) - these are inappropriate when following up a positive Cologuard 1
- Using screening codes when a diagnostic indication exists constitutes improper coding and may result in claim denials or compliance issues 1
Documentation Requirements
- Medical records must clearly document that the colonoscopy is being performed due to a positive Cologuard result 1
- Include the date of the positive Cologuard test and the specific indication for the procedure in the procedure note 1
- If the colonoscopy is negative (no polyps or cancer found), document this clearly, as these patients should return to standard colonoscopy-based surveillance intervals rather than repeat Cologuard testing 1
Clinical Context for Coding
Expected Findings and Their Impact
- Approximately 73% of patients with positive Cologuard will have neither cancer nor advanced adenomas on follow-up colonoscopy (false positive results) 3
- When cancer is detected, it is most commonly found in the sigmoid colon, with 8 out of 10 patients having TNM stage ≥1 disease 3
- Advanced adenomas are found in approximately 24% of patients with positive Cologuard who undergo colonoscopy 3
Timing and Urgency
- Colonoscopy should be scheduled within 60 days according to Veterans Health Administration policy, though evidence suggests completion within 6 months is acceptable 2
- Delays beyond 180 days show a trend toward increasing colorectal cancer risk, becoming statistically significant at >270 days (OR: 1.48, CI 1.05-2.08) 2
- Each additional month of delay increases both CRC incidence and mortality by approximately 0.1 per 1,000 (a 1.4% monthly increase in mortality) 2