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Billing code

A418A — Gastroenterology partial assessment

Gastroenterology partial assessment

Bill A418 for a limited gastroenterology visit: history of the complaint, the needed exam, advice and a record.

Watch for: On a Z-code procedure day after your major pre-operative visit in the past 12 months, only a partial assessment is payable.

Code

A418A

Description

Gastroenterology partial assessment

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

Partial assessment by a gastroenterologist: history of the complaint, needed exam, advice and a record.

What it covers

A partial assessment is a limited service: a history of the presenting complaint, the necessary physical exam, advice to the patient and an appropriate record (GP25).

A418 is the Gastroenterology (41) partial assessment (A104).

Billing rules

• If you decided on a Z-code procedure (such as colonoscopy) at a visit in the past 12 months, a partial assessment is the only assessment you can bill that day before the procedure (SP4 §13).
• Add E098 (+28%) in the office or a hospital out-patient clinic (not ED) for an established diagnosis of Crohn's disease, ulcerative colitis, malnutrition, celiac disease or chronic liver cirrhosis; submit with diagnostic code 263, 555, 556, 571 or 579 (A104, A105).
• E098 is not payable for hospital in-patients, long-term care patients or ED patients (A104).
• Detention (K001) is only payable after 30 minutes (GP30).
• Can be done by video or phone with an existing patient-physician relationship; add K300A or K301A (Appendix J AJ1, A66). E098 also applies to the virtual fee (A74).

Often billed with

• E098 gastroenterology chronic disease assessment premium (A104).
• Diagnostic and therapeutic procedures, payable in addition to an assessment (J3).

Common rejections

• AT3: Usually means it was billed as virtual care (K300A/K301A) and OHIP found no existing patient-physician relationship, such as an in-person service by you in the past 24 months (A66).

Related codes: A415, A413, A414, A411, A120, E098, K001

Source: Schedule of Benefits (July 1, 2026), Consultations and Visits, Gastroenterology (41), page A104; rules GP25, SP4.

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