2026 ICD-10-CM Diagnosis Code A52.04Syphilitic cerebral arteritis
ICD-10-CM Codes›A00–B99›A50-A64›A52
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Chronic Condition
A52.04 is a billable ICD-10-CM diagnosis code for syphilitic cerebral arteritis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 314 through 316. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 96 closely related codes. Coders also document this condition as cerebral arteritis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other and ill-defined cerebrovascular disease and Sexually transmitted infections (excluding HIV and hepatitis).
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Cerebral arteritis
- Syphilitic cerebral arteritis
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
syphilitic A52.04
syphilitic A52.04
brain A52.04
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Brain Diseases
Your brain is the control center of your body. It controls your thoughts, memory, speech, and movement. It regulates the function of many organs. It's part of your nervous system, which also includes your spinal cord and peripheral nerves. The nervous system sends signals between your brain and the rest of the body.
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Convert A52.04 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About A52.04Overview
What is the ICD-10 code for syphilitic cerebral arteritis?
The ICD-10-CM code for syphilitic cerebral arteritis is A52.04 (sometimes written as A5204). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is A52.04 (Cardiovascular and cerebrovascular syphilis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report syphilitic cerebral arteritis on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does A52.04 group to?
When syphilitic cerebral arteritis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 314, 315, 316, with relative weights from 0.6821 to 2.0852 depending on complications. Higher weights mean higher Medicare reimbursement.
Is A52.04 a CC or MCC?
CMS lists A52.04 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 96 closely related codes in its exclusion list.
What is the ICD-9 equivalent of A52.04?
Under the General Equivalence Mappings, syphilitic cerebral arteritis converts to ICD-9-CM 093.89 (cardiovascular syph NEC). The mapping is approximate, so confirm the match fits the documentation.
