G9998 – Documentation of medical reason(s) for an interval of less than 3 years since the last colonoscopy (e.g., last colonoscopy incomplete, last colonoscopy had inadequate prep, piecemeal removal of adenomas, or sessile serrated polyps >= 20 mm in size, last colonoscopy found greater than 10 adenomas, lower gastrointestinal bleeding, or patient at high risk for colon cancer due to underlying medical history ([i.e. crohn's disease, ulcerative colitis, personal or family history of colon cancer, hereditary colorectal cancer syndromes])
HCPCS Level II code · G codes: Procedures / Professional Services (Temporary)
- Long description
- Documentation of medical reason(s) for an interval of less than 3 years since the last colonoscopy (e.g., last colonoscopy incomplete, last colonoscopy had inadequate prep, piecemeal removal of adenomas, or sessile serrated polyps >= 20 mm in size, last colonoscopy found greater than 10 adenomas, lower gastrointestinal bleeding, or patient at high risk for colon cancer due to underlying medical history ([i.e. crohn's disease, ulcerative colitis, personal or family history of colon cancer, hereditary colorectal cancer syndromes])
- Short description
- Doc med rsn <3 colon
- Pricing indicator
00Not separately priced by Part B (bundled, not covered or Part A only)- Medicare coverage
CCarrier judgment – coverage decided by the Medicare contractor- BETOS category
Z2Undefined codes- Added
- January 1, 2022
- Last change
- January 1, 2024 – No change
Frequently asked questions
What is HCPCS code G9998?
G9998 is a HCPCS Level II code for documentation of medical reason(s) for an interval of less than 3 years since the last colonoscopy (e.g., last colonoscopy incomplete, last colonoscopy had inadequate prep, piecemeal removal of adenomas, or sessile serrated polyps >= 20 mm in size, last colonoscopy found greater than 10 adenomas, lower gastrointestinal bleeding, or patient at high risk for colon cancer due to underlying medical history ([i.e. crohn's disease, ulcerative colitis, personal or family history of colon cancer, hereditary colorectal cancer syndromes]).
Does Medicare cover G9998?
The HCPCS file lists coverage code C: Carrier judgment – coverage decided by the Medicare contractor. Coverage and payment also depend on local coverage determinations and the patient’s plan.
Nearby G codes
- G9990 – Patient did not receive any pneumococcal conjugate or polysaccharide vaccine on or after their 19th birthday and before the end of the measurement period
- G9991 – Patient received any pneumococcal conjugate or polysaccharide vaccine on or after their 19th birthday and before the end of the measurement period
- G9992 – Palliative care services used by patient any time during the measurement period
- G9993 – Patient was provided palliative care services any time during the measurement period
- G9994 – Patient is using palliative care services any time during the measurement period
- G9995 – Patients who use palliative care services any time during the measurement period
- G9996 – Documentation stating the patient has received or is currently receiving palliative or hospice care
- G9997 – Documentation of patient pregnancy anytime during the measurement period prior to and including the current encounter
- G9999 – Documentation of system reason(s) for an interval of less than 3 years since the last colonoscopy (e.g., unable to locate previous colonoscopy report, patient cannot provide precise date or details from previous colonoscopy, previous colonoscopy report was incomplete)
Source: CMS HCPCS Level II quarterly file, October 2026. Reference only – check payer policy before billing.