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Billing code

C135A — Internal medicine in-patient consultation

Internal medicine in-patient consultation

Bill C135 for an internist's consultation on a hospital in-patient, at the written request of a physician or nurse practitioner.

Watch for: The signed request must name the referrer and their billing number, or OHIP pays a lesser assessment.

Code

C135A

Description

Internal medicine in-patient consultation

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

Consultation by an internist for a hospital in-patient, at the written request of a physician or nurse practitioner.

What it covers

C135 is the Internal Medicine (13) consultation for non-emergency hospital in-patients (A130). A consultation is an assessment done at the written request of a physician, nurse practitioner (or a dental surgeon for hospital dental work) who wants your opinion because the case is complex, serious or obscure, or because the patient asked for another opinion. It includes a general, specific or medical specific assessment, a review of relevant data and a written report to the referrer (GP16).

Hospital in-patient (C-prefix) services follow GP40–GP48. For emergency calls and other special visits to in-patients, use the General Listings and special visit premiums instead (A130).

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).
• Needs a written, signed request from a physician or nurse practitioner that names you or your specialty, the referrer and their billing number, and the patient and health number. Without it, OHIP pays a lesser assessment (GP16).
• Same patient, same consultant, same diagnosis: one consultation per two consecutive 12-month periods. A second is allowed only for a hospital in-patient or ED patient 12 to 24 months after the first; a clearly unrelated diagnosis allows one every 12 months. Extra consultations pay as an assessment (GP17–GP18).
• When a patient is transferred between physicians during an admission, only one consultation, general or specific assessment or re-assessment is paid per admission (GP40).
• A referral you ask for after seeing the patient does not make the visit a consultation; bill the visit you actually provided (GP16).
• Send a written report with your findings, opinion and recommendations to the referrer, and also to the primary care provider when a nurse practitioner referred (GP16).
• Detention (K001) can be added only after 60 minutes of consultation time (GP30–GP31).
• Video only (not phone), and for a hospital in-patient or LTC resident only if you are not the MRP, the facility has no physician with the needed expertise (documented by the referrer), and the referrer saw the patient in person within the past 30 days (AJ2, A69).

Common rejections

• ARF: OHIP describes this as 'Missing Physician Referring Number': a consultation claim needs the referring physician's or nurse practitioner's billing number (GP16).
• AT2: OHIP describes this as 'Must include video modality': this code is video-only in Appendix J, so it can't be billed by phone with K301A (AJ2).

Related codes: C130, C435, C136, C133, A135, C132, C138

Source: Schedule of Benefits (July 1, 2026), Consultations and Visits, Internal Medicine (13), page A130. Consultation rules GP16–GP19.

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