ICD-10-CM 2027 diagnosis code
A39.51Meningococcal endocarditis
A39.51 is a valid, billable ICD-10-CM code for meningococcal endocarditis. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.
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 A39.51
A39.51 is the ICD-10-CM diagnosis code for meningococcal endocarditis. It belongs to category A39 (meningococcal infection), block A30-A49 (other bacterial diseases) 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 A39.5 (meningococcal heart disease), A39.51 is specifically for meningococcal endocarditis. Related codes cover carditis, unspecified (A39.50), myocarditis (A39.52) and pericarditis (A39.53).
As a secondary diagnosis it is an MCC (major complication or comorbidity), which can move an inpatient stay into the highest-paying "with MCC" 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 288 (Acute and Subacute Endocarditis with MCC, relative weight 2.6315), DRG 289 (Acute and Subacute Endocarditis with CC, relative weight 1.5362), DRG 290 (Acute and Subacute Endocarditis without CC/MCC, relative weight 0.8367), DRG 791 (Prematurity with Major Problems, relative weight 4.1075) and DRG 793 (Full Term Neonate with Major Problems, relative weight 4.2195), in MDC 05 (Diseases and Disorders of the Circulatory System) and MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period), 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 036.42 (meningococcal endocarditis).
Notes that apply from higher levels
Instructions written at a parent level also apply to A39.51.
Broader instructions also apply from Chapter 1: Certain infectious and parasitic diseases.
Alphabetic index entries
4 entriesTerms in the official ICD-10-CM index that lead to A39.51.
- Disease, diseased › heart (organic) › meningococcal › endocarditis
- Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular) › meningococcal
- Infection, infected, infective (opportunistic) › meningococcal › endocardium
- Infection, infected, infective (opportunistic) › meningococcal › heart › endocardium
Codes whose notes reference A39.51
- I39Excludes1
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.
MDC 05 · Diseases and Disorders of the Circulatory System
MDC 15 · Newborns and Other Neonates with Conditions Originating in the Perinatal Period
MDC 15 · Newborns and Other Neonates with Conditions Originating in the Perinatal Period
ICD-9-CM equivalent
Converter →- 036.42Meningococcal endocarditisexact
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about A39.51
Is A39.51 billable?
- Yes. A39.51 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A39.51 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A39.51 as a principal diagnosis.
Is A39.51 a CC or MCC?
- A39.51 is an MCC (major complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.
What DRG does A39.51 group to?
- A39.51 is used in the MS-DRG v44.0 logic for MS-DRG 288 (Acute and Subacute Endocarditis with MCC), MS-DRG 289 (Acute and Subacute Endocarditis with CC), MS-DRG 290 (Acute and Subacute Endocarditis without CC/MCC), MS-DRG 791 (Prematurity with Major Problems) and MS-DRG 793 (Full Term Neonate with Major Problems). 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 A39.51?
- The CMS General Equivalence Mappings map A39.51 to ICD-9-CM 036.42.