2026 ICD-10-CM Diagnosis Code A75.1Recrudescent typhus [Brill's disease]
ICD-10-CM Codes›A00–B99›A75-A79›A75
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Not Chronic
A75.1 is a billable ICD-10-CM diagnosis code for recrudescent typhus [Brill's disease]. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 867 through 869. 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 56 closely related codes. Coders also document this condition as Brill-Zinsser disease. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Parasitic, other specified and unspecified infections.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Brill-Zinsser disease
- Typhus group rickettsial disease
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Brill-Zinsser disease
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Disease, diseased See Also: Syndrome;
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Bacterial Infections
Bacteria are tiny organisms (living things) that have only one cell. Under a microscope, they look like balls, rods, or spirals. They can be found almost everywhere on Earth. There are lots of bacteria in and on your body. In fact, your body has about 10 times more bacteria cells than human cells.
The full article covers:
- What are bacteria?
- How do bacterial infections spread?
- What are the treatments for bacterial infections?
- Can bacterial infections be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert A75.1 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About A75.1Overview
What is the ICD-10 code for recrudescent typhus [Brill's disease]?
The ICD-10-CM code for recrudescent typhus [Brill's disease] is A75.1 (sometimes written as A751). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is A75.1 (Typhus fever) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report recrudescent typhus [Brill's disease] on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does A75.1 group to?
When recrudescent typhus [Brill's disease] is the principal diagnosis on an inpatient stay, it groups to MS-DRG 867, 868, 869, with relative weights from 0.7297 to 2.0932 depending on complications. Higher weights mean higher Medicare reimbursement.
Is A75.1 a CC or MCC?
CMS lists A75.1 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 56 closely related codes in its exclusion list.
What is the ICD-9 equivalent of A75.1?
Under the General Equivalence Mappings, recrudescent typhus [Brill's disease] converts to ICD-9-CM 081.1 (Brill's disease). The mapping is a direct match.
