G0121 and G0105 are strictly medicare hcpcs only.
Effective Jan. 1, 1998, Medicare created HCPCS Level ll codes G0105 and G0121. These codes are equivalent to and are used in place of CPT code 45378 when reporting outpatient colonoscopies for screening of colorectal cancer on Medicare patients. Code G0105 is used for reporting a screening colonoscopy for patients who are at high risk for colorectal cancer. High risk for colorectal cancer means an individual with 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.
HCPCS Level II code G0121 was created to report colonoscopies performed for colorectal screening on patients not meeting criteria for high risk. If an abnormality is found during a screening colonoscopy that results in a therapeutic procedure (e.g., biopsy, polypectomy, excision of lesion), then the appropriate CPT code is used instead of HCPCS Level II codes G0105 or G0121.