Non-Billable / Non-Specific Code
ICD-10-CM I33 is the diagnosis code for Acute and subacute endocarditis. This code falls under the section "Other forms of heart disease" within Chapter 9 — Diseases of the circulatory system (I00-I99). It is a non-billable/non-specific ICD-10-CM code that should not be used for reimbursement. A more specific sub-code is required for billing. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.
The following conditions should never be coded at the same time as I33. They are mutually exclusive:
Understanding where I33 sits in the ICD-10-CM classification helps ensure proper coding:
No, I33 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.
I33 is the ICD-10-CM diagnosis code for "Acute and subacute endocarditis". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
I33 is located in Section I30-I5A — "Other forms of heart disease" within Chapter 9 of the ICD-10-CM Tabular List.
I33 has 2 sub-code(s) that provide more specific detail: I33.0, I33.9.
Use I33 when the patients documented diagnosis matches "Acute and subacute endocarditis" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.
The ICD-10-CM code for Acute and subacute endocarditis is I33.
No, I33 is non-billable. Use a more specific sub-code for primary diagnosis billing.
I33 is in Chapter 9 of the ICD-10-CM Tabular List.
Type 1 Excludes for I33 include: acute rheumatic endocarditis (I01.1); endocarditis NOS (I38).
Yes, I33 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.