2027 ICD-10-CM Diagnosis Code A77.49Other ehrlichiosis
ICD-10-CM Codes›A00–B99›A75-A79›A77
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Not Chronic
A77.49 is a billable ICD-10-CM diagnosis code for other ehrlichiosis. 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 57 closely related codes. Coders also document this condition as anaplasmosis. 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.
- Anaplasmosis
- Human anaplasmosis caused by Anaplasma phagocytophilum
- Human ehrlichiosis
- Human ehrlichiosis caused by Ehrlichia ewingii
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to A77.49: its own notes plus those printed at A77.4 and 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.
- 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.
- Ehrlichiosis due to E. ewingii
- Ehrlichiosis due to E. muris euclairensis
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
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.
- 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.
- code to identify resistance to antimicrobial drugs (Z16.-)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
E. ewingii A77.49
E. muris euclairensis A77.49
specified organism NEC A77.49
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Ehrlichiosis
a tick-borne disease characterized by fever; headache; myalgias; anorexia; and occasionally rash. it is caused by several bacterial species and can produce disease in dogs; cattle; sheep; goats; horses; and humans. the primary species causing human disease are ehrlichia chaffeensis; anaplasma phagocytophilum; and ehrlichia ewingii.
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 A77.49 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About A77.49Overview
What is the ICD-10 code for other ehrlichiosis?
The ICD-10-CM code for other ehrlichiosis is A77.49 (sometimes written as A7749). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is A77.49 (Ehrlichiosis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report other ehrlichiosis on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does A77.49 group to?
When other ehrlichiosis 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 A77.49 a CC or MCC?
CMS lists A77.49 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 57 closely related codes in its exclusion list.
Can A77.49 be reported with A79.82?
Not as a rule. The Excludes1 note at A77.4, which applies to A77.49, lists "anaplasmosis [A. phagocytophilum] (A79.82)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
