In ICD-10-CM coding, when a patient has an acute myocardial infarction and type 2 diabetes with nephropathy, which diagnosis should be listed first?

In ICD-10-CM coding, when a patient has an acute myocardial infarction and type 2 diabetes with nephropathy, which diagnosis should be listed first?

• A. Type 2 diabetes with nephropathy as primary diagnosis
• B. Acute myocardial infarction as primary diagnosis
• C. Both diagnoses listed as primary
• D. Sequence determined by provider preference

Answer: (B)

The main idea is that the principal (first-listed) diagnosis should reflect the condition that chiefly explains the patient’s admission. An acute myocardial infarction is an acute, life-threatening event that typically drives hospitalization and urgent treatment, so it is listed first. The chronic condition, type 2 diabetes with nephropathy, is a significant comorbidity that would be coded as a secondary diagnosis to capture the patient’s overall condition and the nephropathy, but it does not take primary priority for the admission reason. Sequencing based on provider preference isn’t correct here because ICD-10-CM inpatient coding follows the guideline that the principal diagnosis is the condition responsible for the admission. If the patient had been admitted for diabetic care specifically and the MI occurred incidentally, sequencing could differ, but in this scenario the acute MI should be listed first.

The main idea is that the principal (first-listed) diagnosis should reflect the condition that chiefly explains the patient’s admission. An acute myocardial infarction is an acute, life-threatening event that typically drives hospitalization and urgent treatment, so it is listed first. The chronic condition, type 2 diabetes with nephropathy, is a significant comorbidity that would be coded as a secondary diagnosis to capture the patient’s overall condition and the nephropathy, but it does not take primary priority for the admission reason. Sequencing based on provider preference isn’t correct here because ICD-10-CM inpatient coding follows the guideline that the principal diagnosis is the condition responsible for the admission. If the patient had been admitted for diabetic care specifically and the MI occurred incidentally, sequencing could differ, but in this scenario the acute MI should be listed first.