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Billing code

Z491A — Follow Up Of Incomplete Polyp Resection

Colonoscopy after incomplete polyp removal

Bill for a follow-up colonoscopy to check a partly or piecemeal removed polyp, or one with high-grade dysplasia, is gone.

Watch for: Not payable more than 6 months after the first colonoscopy, and only one colonoscopy code per patient per day.

Code

Z491A

Description

Follow Up Of Incomplete Polyp Resection

FHO+ basket

Not in the FHO+ base rate basket (Schedule 2 or 2B).

Effective date

Apr 1, 2026

Termination date

No end date

Explanation

Updated October 26, 2026

Follow-up colonoscopy within 6 months to check that a partly removed or piecemeal-removed polyp is fully gone.

What it covers

Z491 is a follow-up colonoscopy after incomplete polyp resection (S17).

It is for sessile polyps that were only partly removed, or adenomatous polyps that were removed piecemeal or contained high-grade dysplasia. These patients should be considered for follow-up at short intervals (2 to 6 months) to confirm complete removal (S16, S17).

Billing rules

• Only for sessile polyps that were partly removed, or adenomatous polyps removed piecemeal or with high-grade dysplasia (S17).
• Not payable more than 6 months after the first colonoscopy (S17).
• Only one of Z491, Z492, Z493, Z494, Z495, Z496, Z497, Z498, Z499 or Z555 is payable per patient per day, and sigmoidoscopy Z580 is not payable with it the same day (S15, S17).
• The fee covers sigmoid to descending colon; add E740 (splenic flexure), E741 (hepatic flexure), E747 (cecum) or E705 (terminal ileum) for the extent reached. Fulguration is included (S18, S19).
• Add E749 when done in a private office; not payable in a hospital or ICHSC (S18, S19).
• Anaesthesia is billed as E032C (4 basic units plus time units); E003C is not payable, and GP97 time and extra units aren't payable on the colonoscopy C-suffix code (GP100, S18).
• Colonoscopy for chronic constipation is only insured for patients 50 or older, with a family history of increased cancer risk, or with alarm features (S18).
• Same-day assessment by Internal Medicine or Gastroenterology: see A120 (A104, S19). A pre-colonoscopy consultation is only payable if the chart shows it was medically necessary (GP18).

Often billed with

• E740, E741, E747 or E705 for extent beyond the descending colon (S18).
• Polypectomy Z571, Z518, Z517 or Z516 by size of the largest polyp, plus E720, E520, E519 or E518 for up to 2 more polyps per day; polyps under 3 mm aren't payable (S19).
• E749 when done in a private office (S18).
• E785 for IBD surveillance biopsies with diagnostic code 555, 556 or 576 and the required technique (S18, S19).

Related codes: Z498, Z495, Z494, Z516, E747, E749, A120

Source: Schedule of Benefits (July 1, 2026), Digestive System Surgical Procedures, Intestines (Except Rectum), Colonoscopy, page S17.

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