ICD-10-CM Codes for Sepsis

Updated for 2025. Guide to coding Sepsis, Severe Sepsis, and Septic Shock correctly.

Common Sepsis Codes (Category A40-A41)

Sepsis coding is strictly regulated by guidelines regarding sequencing. The underlying infection is typically sequenced first, followed by severe sepsis codes if applicable. Severe sepsis (R65.2) can NEVER be a primary diagnosis.

Code Description
A41.9 Sepsis, unspecified organism
A41.51 Sepsis due to Escherichia coli [E. coli]
A41.01 Sepsis due to Methicillin susceptible Staphylococcus aureus
R65.20 Severe sepsis without septic shock
R65.21 Severe sepsis with septic shock

Sequencing Alert

For Severe Sepsis, you must code the underlying infection first (e.g., A41.9), followed by a code from subcategory R65.2 (Severe Sepsis). You also need additional codes for the specific organ dysfunctions.

Frequently Asked Questions

Can I use R65.21 (Septic Shock) as the primary diagnosis?

No. According to ICD-10-CM guidelines, septic shock (R65.21) is a secondary diagnosis. The primary diagnosis must be the systemic infection (e.g., A41.xx).

What if the organism is unknown?

Use A41.9 (Sepsis, unspecified organism). Do not use urosepsis codes directly as they are not definitive; map "urosepsis" to A41.9 + Source infection (e.g. UTI N39.0).

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