Colonoscopy Coding: Screening vs. Diagnostic, Polypectomy, and Modifier PT
Colonoscopy coding hinges first on intent — screening vs. diagnostic — and then on what was done to any lesions found.
Screening vs. diagnostic
- G0121 — screening colonoscopy, average risk (Medicare)
- G0105 — screening colonoscopy, high risk (Medicare)
- 45378 — diagnostic colonoscopy (base code)
When a screening exam becomes therapeutic (a polyp is removed), append modifier -PT (Medicare) or -33 (commercial) so the patient's screening benefit still applies — this preserves the waived cost-share and is frequently missed.
Polypectomy by technique
- 45380 — with biopsy
- 45384 — removal by hot biopsy forceps / bipolar cautery
- 45385 — removal by snare
- 45388 — with ablation
Report the base once. When different techniques are used on different lesions, they are separately reportable (with -59/XU and documentation of the distinct lesions); the same technique on multiple polyps is reported once.
Clinical Capture reads the intent and per-lesion techniques from the report and assembles the correct base-plus-technique coding with the right screening modifier.
This article is educational and not coding, billing, or legal advice. Always verify codes and values against the current CPT®, ICD-10-CM, and CMS Physician Fee Schedule, follow NCCI edits and payer policy, and confirm with a certified coder before submitting a claim. Document only work that was actually performed.