OHIP Billing Guide🩺 ServicePublished 2026
C413

C413 OHIP Billing Code: Medical Specific Assessment for Gastroenterologists

The C413 billing code is used by gastroenterologists for conducting detailed medical specific assessments of hospital in-patients. It ensures comprehensive evaluation of digestive-related conditions.

For Ontario Physicians & Billing StaffOHIP Schedule of Benefits Reference95.95 CAD~3 min read

1What Is the C413 OHIP Code?

What is the C413 Billing Code?

The C413 OHIP billing code refers to a medical specific assessment conducted by gastroenterologists on hospital in-patients. This assessment involves a full history and detailed examination of a patient's presenting digestive complaint, which may include issues such as iron deficiency, elevated liver enzymes, or hospital-acquired diarrhoea.

In gastroenterology, this assessment is critical for diagnosing and managing acute and potentially complex digestive health issues within a hospital setting. It is crucial to provide a detailed examination that supports diagnosis and treatment planning, contributing to better patient outcomes. However, the comprehensive nature of the assessment often leads to it being underutilized due to stringent documentation and time-tracking requirements.

2Related Codes

CodeNameFrequencyDescription
A413A413 Medical specific assessmentOnce per patient per physician per 12 months unless exceptions applyOut-patient equivalent service for medical specific assessment.
A411A411 Complex medical specific re-assessmentAs needed with justification for complexityComplex re-assessment service in gastroenterology.
A414A414 Medical specific re-assessmentAs needed if criteria metRe-assessment service for ongoing care management.
C411C411 Complex medical specific re-assessmentAs needed with complexity criteriaIn-patient service for complex re-assessment.

3Eligibility Requirements

Eligibility Requirements for C413

To be eligible for billing code C413, the gastroenterologist must perform the medical specific assessment for non-emergency hospital in-patients. Per the OHIP Schedule of Benefits:

  • Frequency Limit: It can only be billed once per patient per physician per 12-month period unless a second assessment is warranted due to a clearly different diagnosis or a hospital admission assessment after 90 days.
  • Diagnostic Codes: Claims must be submitted with one of the following diagnostic codes: 263, 555, 556, 571, or 579.
  • Virtual Care: C413 may be rendered virtually as C413A via video but not via telephone.
  • Specific Assessment Needs: A full history, detailed examination, and duration of service starting and ending times must be recorded in the patient’s permanent medical record.

4What Your Clinical Note Must Show

1Documenting a Medical Specific Assessment

Physicians must ensure that all aspects of the service are accurately documented.

  • Record a full history and detailed examination of the presenting complaint.
  • Document the start and end times of the service.
  • Use the correct diagnostic codes (263, 555, 556, 571, or 579).

5Weak vs. Strong Note Examples

The strong note succeeds by providing comprehensive patient details, specific examination findings, a correct diagnostic code, and appropriate time documentation. The weak note fails due to its lack of detail and specific documentation required for billing.

Weak Note

Patient assessed for digestive issues. Treatment plan provided. Details sparse.

Strong Note

Patient presented with severe hospital-acquired diarrhoea. Complete history taken including recent antibiotic use and dietary changes. Detailed examination of abdominal region revealed tenderness. Diagnostic code 579 applied. Duration: 13:30 to 14:15.

  • Describes the presenting complaint and history.
  • Detailed examination findings and diagnostic code.
  • Proper time documentation.

6Common Reasons This Code Is Missed

1
Incomplete Time Documentation
Physicians often forget to document the start and end time, which is crucial for OHIP billing.
2
Misapplication of Diagnostic Codes
Using incorrect diagnostic codes is a common reason for rejection of claims under this code.
3
Ignoring Frequency Limits
Billing more than once per patient per physician per 12 months without meeting criteria for exceptions.
4
Inadequate Examination Details
Failing to perform or document a detailed examination can result in missed billing opportunities.
Document C413 correctly — every time
Empathia's templates automatically structure your notes to capture every required element for audit-proof billing.

8Frequently Asked Questions

How often can I bill for a C413 under OHIP?
C413 can be billed once per patient per physician per 12 months, with exceptions allowing for a second billable assessment if certain criteria are met.
Can C413 be rendered virtually?
Yes, C413 can be rendered virtually as C413A via video; however, telephone delivery is not eligible.
What conditions necessitate a medical specific assessment in gastroenterology?
Common conditions include iron deficiency, rise in liver enzymes, and hospital-acquired diarrhoea.
What are typical findings that justify the use of C413 in gastroenterology?
Significant findings such as severe diarrhoea, substantial liver enzyme disturbances, or complex iron deficiency management justify this code.
What should lead to an additional assessment within the 12-month period?
A patient presenting with a clearly different, unrelated diagnosis or a hospital admission assessment after 90 days.
In what patient scenarios is C413 most applicable?
Mostly used for in-patients admitted with acute digestive issues that require thorough evaluation.
What documentation is required for billing C413?
A complete history, detailed examination, start and end times recorded, and appropriate diagnostic coding.
Disclaimer: This article is intended as a general educational resource for physicians and billing staff. It does not constitute billing advice or a definitive interpretation of the OHIP Schedule of Benefits. Always verify current billing codes, eligibility criteria, and documentation requirements directly against the official Schedule of Benefits or consult with a qualified medical billing specialist.
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