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Billing code

A183A — Medical Specific Assessment

Neurology full assessment

A neurologist bills A183 for a full history of the presenting complaint and detailed exam of the affected systems, outside the patient's home.

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

Code

A183A

Description

Medical Specific Assessment

FHO+ basket

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

Effective date

Jun 1, 2025

Termination date

No end date

Explanation

Updated October 26, 2026

A neurologist's full assessment of the presenting complaint with a detailed exam of the affected systems, outside the patient's home.

What it covers

A medical specific assessment is a specialist service, rendered somewhere other than the patient's home, that needs a full history of the presenting complaint and a detailed examination of the affected part(s), region(s) or system(s) needed to make a diagnosis, exclude disease and/or assess function (GP23).

A183 is the Neurology (18) office and general listing. The hospital in-patient version is C183 (A140, A144).

Billing rules

• Limited to 1 per patient per physician per 12 months. The limit rises to 2 if the patient returns with a clearly different, unrelated diagnosis, or if at least 90 days have passed and the second one is a hospital admission assessment. Extra ones are paid as a lesser assessment (GP23).
• Medical specific assessments and complex medical specific re-assessments (A181) combined are limited to 4 per patient per physician per 12 months (GP23).
• Add E078 (+50%) when the patient has an established chronic disease from the GP26 list (for example 290 dementia, 332 Parkinson's disease, 340 multiple sclerosis, 343 cerebral palsy, 345 epilepsy) and you see them in the office or a hospital out-patient clinic, not the emergency department (GP25–GP26).
• Can be done by video or phone when you have an existing patient-physician relationship; add K300A (video) or K301A (phone). Phone pays 85% of the in-person fee (Appendix J AJ1, A70).

Often billed with

• E078 chronic disease assessment premium for an established chronic diagnosis on the GP26 list (GP25).

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 visit with you in the past 24 months (A66).

Related codes: A184, A181, A188, A185, A113, C183, E078

Source: Schedule of Benefits (July 1, 2026), Consultations and Visits, Neurology (18), page A140. Rules GP23, GP25–GP26.

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