Non-Billable / Non-Specific Code
ICD-10-CM I21.1 is the diagnosis code for ST elevation (STEMI) myocardial infarction of inferior wall. This code falls under the section "Ischemic heart diseases" 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.
Understanding where I21.1 sits in the ICD-10-CM classification helps ensure proper coding:
No, I21.1 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.
I21.1 is the ICD-10-CM diagnosis code for "ST elevation (STEMI) myocardial infarction of inferior wall". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
The parent code of I21.1 is I21 ("Acute myocardial infarction"). I21.1 provides a more specific classification within this category.
I21.1 is located in Section I20-I25 — "Ischemic heart diseases" within Chapter 9 of the ICD-10-CM Tabular List.
I21.1 has 2 sub-code(s) that provide more specific detail: I21.11, I21.19.
Use I21.1 when the patients documented diagnosis matches "ST elevation (STEMI) myocardial infarction of inferior wall" 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 ST elevation (STEMI) myocardial infarction of inferior wall is I21.1.
No, I21.1 is non-billable. Use a more specific sub-code for primary diagnosis billing.
I21.1 is in Chapter 9 of the ICD-10-CM Tabular List.
Yes, I21.1 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.