If a type 1 NSTEMI evolves to STEMI, what code should be assigned?

When coding for a type 1 NSTEMI that evolves into a STEMI, it is important to understand the progression of the myocardial infarction. In the context of ICD-10-CM coding, NSTEMI refers to a non-ST elevation myocardial infarction, while STEMI indicates a ST elevation myocardial infarction. The coding guidelines stipulate that when a type 1 NSTEMI progresses to STEMI, the appropriate code to capture this situation reflects the acute phase of the condition.

The correct coding practice does not capture that a NSTEMI has evolved into a STEMI using codes specific to NSTEMI, rather it necessitates using a code that confirms the patient is currently experiencing a STEMI. The coding hierarchy prioritizes the most acute event when documenting myocardial infarctions, thus the appropriate code in this scenario is indeed the one representing STEMI.

The code I21.4 refers to a non-ST elevation myocardial infarction, while I21.3 denotes a specific type of STEMI not capturing this transition adequately. The I22 code pertains to subsequent myocardial infarctions and is used in cases of recurrent events after an initial MI, which would not apply directly to this acute evolution case. Therefore, if the NSTEMI has progressed