2027 ICD-10-CM Diagnosis Code A39.9Meningococcal infection, unspecified
ICD-10-CM Codes›A00–B99›A30-A49›A39
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Not Chronic
A39.9 is a billable ICD-10-CM diagnosis code for meningococcal infection, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 870 through 872. 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 9 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Invasive meningococcal disease
- Meningococcal infectious disease
- Meningococcal infectious disease caused by Neisseria meningitidis serogroup A
- Meningococcal infectious disease caused by Neisseria meningitidis serogroup B
- Meningococcal infectious disease caused by Neisseria meningitidis serogroup C
- Meningococcal infectious disease caused by Neisseria meningitidis serogroup W
- Meningococcal infectious disease caused by Neisseria meningitidis serogroup Y
- Recurrent infection caused by Gram-negative bacteria
- Recurrent infection caused by Neisseria
- Recurrent infection caused by Neisseria meningitidis
- Sepsis due to infection caused by Neisseria meningitidis
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to A39.9: 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.
- 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.
- Meningococcal disease NOS
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.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name A39.9, its category, or a range that includes it.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Infection, infected, infective (opportunistic) B99.9
meningococcal See Also: condition; A39.9
parameningococcus NOS A39.9
Meningococcus, meningococcal See Also: condition; A39.9
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Meningococcal Infections
infections with bacteria of the species neisseria meningitidis.
Patient EducationClinical
Meningococcal Disease
Meningococcal disease is the name for any illness that is caused by Neisseria meningitidis bacteria (also called meningococcal bacteria). These illnesses are often severe and can sometimes be deadly. They include infections of the lining of the brain and spinal cord (meningitis) and in the bloodstream (sepsis).
The full article covers:
- What is meningococcal disease?
- What causes meningococcal disease?
- Who is more likely to get meningococcal disease?
- What are the symptoms of meningococcal disease?
- How is meningococcal disease diagnosed?
- What are the treatments for meningococcal disease?
- Can meningococcal disease be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert A39.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About A39.9Overview
What is the ICD-10 code for meningococcal infection, unspecified?
The ICD-10-CM code for meningococcal infection, unspecified is A39.9 (sometimes written as A399). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is A39.9 (Meningococcal infection) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report meningococcal infection, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does A39.9 group to?
When meningococcal infection, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 872, 871, 870, with relative weights from 1.0066 to 6.9432 depending on complications. Higher weights mean higher Medicare reimbursement.
Is A39.9 a CC or MCC?
CMS lists A39.9 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 9 closely related codes in its exclusion list.
What is the ICD-9 equivalent of A39.9?
Under the General Equivalence Mappings, meningococcal infection, unspecified converts to ICD-9-CM 036.9 (meningococcal infect NOS). The mapping is a direct match.
