2027 ICD-10-CM Diagnosis Code A79.82Anaplasmosis [A. phagocytophilum]

ICD-10-CM Codes›A00–B99›A75-A79›A79

ICD-10-CM A79.82
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

A79.82 is a billable ICD-10-CM diagnosis code for anaplasmosis [A. phagocytophilum]. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) 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 4 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Parasitic, other specified and unspecified infections.

Code Identity

ICD-10-CM Code
A79.82
Billable Status
Yes — Valid for Submission
Code Describes
Anaplasmosis [A. phagocytophilum]
Short Description
Anaplasmosis [A. phagocytophilum]
Same as the full description in the CMS dataset.
Parent Code
A79.8
Other specified rickettsioses

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA75-A79Rickettsioses
CategoryA79Other rickettsioses
This CodeA79.82Anaplasmosis [A. phagocytophilum]

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to A79.82: its own notes plus those printed at Chapter 1. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • diseases generally recognized as communicable or transmissible

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Transfusion transmitted A. phagocytophilum

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • carrier or suspected carrier of infectious disease (Z22.-)
  • certain localized infections - see body system-related chapters
  • infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
  • infectious and parasitic diseases specific to the perinatal period (P35-P39)
  • influenza and other acute respiratory infections (J00-J22)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • code to identify resistance to antimicrobial drugs (Z16.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name A79.82, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming A79.82: they are not reported together with it, unless the two conditions are unrelated.

  • A77.4 Ehrlichiosis
    anaplasmosis [A. phagocytophilum] (A79.82)

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INF009
Parasitic, other specified and unspecified infections
Default principal diagnosis: inpatient Yes · outpatient Yes

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.

Code History & ChangesHistory

Replacement A79.82 replaces the following previously assigned code(s):

  • A77.49 - Other ehrlichiosis
FY 2022AddedAdded to the ICD-10-CM code setEffective October 1, 2021.
FY 2023–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About A79.82Overview

What is the ICD-10 code for anaplasmosis [A. phagocytophilum]?

The ICD-10-CM code for anaplasmosis [A. phagocytophilum] is A79.82 (sometimes written as A7982). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is A79.82 (Other specified rickettsioses) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report anaplasmosis [A. phagocytophilum] on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does A79.82 group to?

When anaplasmosis [A. phagocytophilum] is the principal diagnosis on an inpatient stay, it groups to MS-DRG 867, 869, 868, with relative weights from 0.6784 to 2.1855 depending on complications. Higher weights mean higher Medicare reimbursement.

Is A79.82 a CC or MCC?

CMS lists A79.82 as a CC (complication or comorbidity) for FY 2027. 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 4 closely related codes in its exclusion list.