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ICD-10-CM 2027 diagnosis code

A79.1Rickettsialpox due to Rickettsia akari

✓ Billable / specificCC — complication/comorbidity

A79.1 is a valid, billable ICD-10-CM code for rickettsialpox due to rickettsia akari. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Looking up by condition? See ICD-10 code for Rickettsialpox.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About A79.1

A79.1 is the ICD-10-CM diagnosis code for Rickettsialpox due to Rickettsia akari. It belongs to category A79 (other rickettsioses), block A75-A79 (rickettsioses) and chapter 1 (certain infectious and parasitic diseases). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within A79 (other rickettsioses), A79.1 is specifically for Rickettsialpox due to Rickettsia akari. Related codes cover Trench fever (A79.0), other specified rickettsioses (A79.8) and rickettsiosis, unspecified (A79.9).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 867 (Other Infectious and Parasitic Diseases Diagnoses with MCC, relative weight 2.1859), DRG 868 (Other Infectious and Parasitic Diseases Diagnoses with CC, relative weight 1.0235) and DRG 869 (Other Infectious and Parasitic Diseases Diagnoses without CC/MCC, relative weight 0.6787), in MDC 18 (Infectious and Parasitic Diseases, Systemic or Unspecified Sites), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 083.2 (Rickettsialpox).

Coding notes

Applicable toConditions and synonyms classified to this code
  • Kew Garden fever
  • Vesicular rickettsiosis

Notes that apply from higher levels

Instructions written at a parent level also apply to A79.1.

Broader instructions also apply from Chapter 1: Certain infectious and parasitic diseases.

Alphabetic index entries

5 entries

Terms in the official ICD-10-CM index that lead to A79.1.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

ICD-9-CM equivalent

Converter →
  • 083.2Rickettsialpoxapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about A79.1

Is A79.1 billable?

Yes. A79.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can A79.1 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict A79.1 as a principal diagnosis.

Is A79.1 a CC or MCC?

A79.1 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.

What DRG does A79.1 group to?

A79.1 is used in the MS-DRG v44.0 logic for MS-DRG 867 (Other Infectious and Parasitic Diseases Diagnoses with MCC), MS-DRG 868 (Other Infectious and Parasitic Diseases Diagnoses with CC) and MS-DRG 869 (Other Infectious and Parasitic Diseases Diagnoses without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for A79.1?

The CMS General Equivalence Mappings map A79.1 to ICD-9-CM 083.2.