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Billing code

A133A — Internal medicine medical specific assessment

Internal medicine full assessment

An internist bills A133 for a full history of the presenting problem and a detailed exam of the affected systems.

Watch for: One per patient per physician per 12 months, two only for an unrelated diagnosis or later admission; extras pay a lesser fee.

Code

A133A

Description

Internal medicine medical specific 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

Full specialist assessment by an internist of the presenting problem: complete history and detailed exam of the affected systems.

What it covers

A133 is the Internal Medicine (13) medical specific assessment (A129). A medical specific assessment needs a full history of the presenting complaint and a detailed examination of the affected parts, regions or systems needed to make a diagnosis, exclude disease or assess function. It is done by a specialist, somewhere other than the patient's home (GP23).

Billing rules

• Specialists bill from the Consultations and Visits listing for their own Royal College specialty on file with the Ministry, here Internal Medicine (13) (GP9).
• One per patient per physician per 12 months, or two if the patient returns with a clearly different, unrelated diagnosis or (at least 90 days after the last) the second is a hospital admission assessment. Extra ones pay a lesser fee (GP23).
• Medical specific assessments and complex medical specific re-assessments together are limited to 4 per patient per physician per 12 months; extras pay a lesser fee (GP23–GP24).
• Can be done by video or phone when you have an existing relationship with the patient (for example, an in-person visit with you in the past 24 months). Add K300A (video) or K301A (phone); phone pays 85% of the fee (AJ1, A66, A70).

Common rejections

• AT3: Billed as virtual care (K300A/K301A) but OHIP found no existing patient-physician relationship, such as an in-person service with you in the past 24 months (A66).

Related codes: A134, A131, A138, A135, C133, A120

Source: Schedule of Benefits (July 1, 2026), Consultations and Visits, Internal Medicine (13), page A129. Assessment rules GP23–GP25.

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