A39.1 Waterhouse-Friderichsen syndrome

The ICD-10-CM code for Waterhouse-Friderichsen syndrome is A39.1 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

1: Certain infectious and parasitic diseases (A00-B99)

Section

A30-A49: Other bacterial diseases (A30-A49)

Category A39

18 codes (15 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to A39.1:

• Friderichsen-Waterhouse syndrome or disease
• Waterhouse (-Friderichsen) syndrome or disease (meningococcal)
• Adrenalitis, adrenitis › meningococcal, hemorrhagic
• Syndrome › Friderichsen-Waterhouse
• Meningococcus, meningococcal › adrenalitis, hemorrhagic
• Apoplexia, apoplexy, apoplectic › adrenal
• Disease, diseased › Waterhouse-Friderichsen
• Sepsis (generalized) (unspecified organism) › adrenal hemorrhage syndrome (meningococcal)

Inclusion Terms

• Meningococcal hemorrhagic adrenalitis
• Meningococcic adrenal syndrome

U.S. Hospital Utilization

• An estimated 65 U.S. inpatient stays in 2023 included A39.1 among the documented diagnoses.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

HIV Infections (TOC entry)

a. Human Immunodeficiency Virus (HIV) Infections .............................................................. 19

Infectious agents causing diseases in other chapters (TOC)

b. Infectious agents as the cause of diseases classified to other chapters ................................. 22

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)