2026 ICD-10-CM Diagnosis Code B05.2Measles complicated by pneumonia
ICD-10-CM Codes›A00–B99›B00-B09›B05
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Not Chronic
B05.2 is a billable ICD-10-CM diagnosis code for measles complicated by pneumonia. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 177 through 179, 791, 793. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 22 closely related codes. Coders also document this condition as exanthem caused by Measles morbillivirus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Pneumonia (except that caused by tuberculosis) and Viral infection.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Exanthem caused by Measles morbillivirus
- Giant cell pneumonia
- Pneumonia due to measles
- Post measles pneumonia
- Sequela of infection caused by Morbillivirus
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Postmeasles pneumonia
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
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.
Clinical InformationClinical
Measles
a highly contagious infectious disease caused by morbillivirus, common among children but also seen in the nonimmune of any age, in which the virus enters the respiratory tract via droplet nuclei and multiplies in the epithelial cells, spreading throughout the mononuclear phagocyte system.Measles Vaccine
a live attenuated virus vaccine of chick embryo origin, used for routine immunization of children and for immunization of adolescents and adults who have not had measles or been immunized with live measles vaccine and have no serum antibodies against measles. children are usually immunized with measles-mumps-rubella combination vaccine. (from dorland, 28th ed)Measles virus
the type species of morbillivirus and the cause of the highly infectious human disease measles, which affects mostly children.Measles-Mumps-Rubella Vaccine
a combined vaccine used to prevent measles; mumps; and rubella.Rubella
an acute infectious disease caused by the rubella virus. the virus enters the respiratory tract via airborne droplet and spreads to the lymphatic system.Rubella virus
the type (and only) species of rubivirus causing acute infection in humans, primarily children and young adults. humans are the only natural host. a live, attenuated vaccine is available for prophylaxis.Subacute Sclerosing Panencephalitis
a rare, slowly progressive encephalitis caused by chronic infection with the measles virus. the condition occurs primarily in children and young adults, approximately 2-8 years after the initial infection. a gradual decline in intellectual abilities and behavioral alterations are followed by progressive myoclonus; muscle spasticity; seizures; dementia; autonomic dysfunction; and ataxia. death usually occurs 1-3 years after disease onset. pathologic features include perivascular cuffing, eosinophilic cytoplasmic inclusions, neurophagia, and fibrous gliosis. it is caused by the sspe virus, which is a defective variant of measles virus. (from adams et al., principles of neurology, 6th ed, pp767-8)Viral Fusion Proteins
proteins, usually glycoproteins, found in the viral envelopes of a variety of viruses. they promote cell membrane fusion and thereby may function in the uptake of the virus by cells.Rubivirus
a genus of the family togaviridae containing only one recognized species, rubella virus. transmission is primarily by aerosolization.
Patient EducationClinical
Measles
Measles is an infectious disease caused by a virus. It spreads easily from person to person. It causes a blotchy red rash. The rash often starts on the head and moves down the body. Other symptoms include:
Read the full article at MedlinePlus
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Convert B05.2 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About B05.2Overview
What is the ICD-10 code for measles complicated by pneumonia?
The ICD-10-CM code for measles complicated by pneumonia is B05.2 (sometimes written as B052). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is B05.2 (Measles) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report measles complicated by pneumonia on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does B05.2 group to?
When measles complicated by pneumonia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 177, 178, 179, 791, 793, with relative weights from 0.7550 to 4.1696 depending on complications. Higher weights mean higher Medicare reimbursement.
Is B05.2 a CC or MCC?
CMS lists B05.2 as an MCC (major complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 22 closely related codes in its exclusion list.
What is the ICD-9 equivalent of B05.2?
Under the General Equivalence Mappings, measles complicated by pneumonia converts to ICD-9-CM 055.1 (postmeasles pneumonia). The mapping is a direct match.
