2027 ICD-10-CM Diagnosis Code B25.8Other cytomegaloviral diseases
ICD-10-CM Codes›A00–B99›B25-B34›B25
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 6
- Not Chronic
B25.8 is a billable ICD-10-CM diagnosis code for other cytomegaloviral diseases. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 865 through 866, 974 through 976. 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 19 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Viral infection.
For Medicare Advantage risk adjustment, B25.8 maps to CMS-HCC Category 6 (Opportunistic Infections) under the V28 model, adding a risk factor of about 0.381 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
B25.8 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acute gastric ulcer caused by Cytomegalovirus
- Chorioretinitis of bilateral eyes caused by Cytomegalovirus humanbeta5
- Chorioretinitis of left eye caused by Cytomegalovirus humanbeta5
- Chorioretinitis of right eye caused by Cytomegalovirus humanbeta5
- Chronic gastric ulcer caused by Cytomegalovirus
- Cytomegaloviral colitis
- Cytomegaloviral dacryoadenitis
- Cytomegaloviral enteritis
- Cytomegaloviral gastritis
- Cytomegaloviral polyneuropathy
- Cytomegaloviral retinitis
- Cytomegalovirus chorioretinitis
- Cytomegalovirus encephalitis
- Cytomegalovirus infection of skin
- Cytomegalovirus-induced glomerulonephritis
- Duodenitis caused by Cytomegalovirus
- Endocochlear cytomegalovirus infection
- Esophagitis caused by Cytomegalovirus
- Gastric ulcer caused by cytomegalovirus
- Gastric ulcer caused by virus
- Infection involving inner ear
- Infection of central nervous system caused by Cytomegalovirus
- Infection of intestine caused by Human cytomegalovirus 5
- Infection of lacrimal gland caused by virus
- Meningitis caused by Human cytomegalovirus 5
- Retinitis of bilateral eyes caused by cytomegalovirus
- Retinitis of left eye caused by cytomegalovirus
- Retinitis of right eye caused by cytomegalovirus
- Ulcerative cytomegalovirus lesion
- Viral colitis
- Viral duodenitis
- Viral esophagitis
- Viral kidney infection
- Viral labyrinthitis
- Viral posterior uveitis
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to B25.8: its own notes plus those printed at B25 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.
- Cytomegaloviral encephalitis
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.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name B25.8, its category, or a range that includes it.
Applicable To 1
These notes mention B25.8.
- O98.5 Other viral diseases complicating pregnancy, childbirth and the puerperium
Excludes1 1
These codes carry an Excludes1 note naming B25.8: they are not reported together with it, unless the two conditions are unrelated.
- A85 Other viral encephalitis, not elsewhere classifiedencephalitis due to cytomegalovirus (B25.8)
Excludes2 1
These codes carry an Excludes2 note naming B25.8: its condition is not part of those codes, and both may be reported when the patient has both.
Code First 1
These codes say to code first a condition named in the note, and B25.8 is one of the conditions named.
- G05 Encephalitis, myelitis and encephalomyelitis in diseases classified elsewherecytomegaloviral encephalitis, myelitis and encephalomyelitis (B25.8)
Use Additional Code 1
These codes say to use an additional code from the note, and B25.8 is one of the codes named.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Disease, diseased See Also: Syndrome;
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Cytomegalovirus Infections
Cytomegalovirus (CMV) is a virus found around the world. It is related to the viruses that cause chickenpox and infectious mononucleosis (mono). Between 50% and 80% of adults in the United States have had a CMV infection by age 40. Once CMV is in a person's body, it stays there for life.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert B25.8 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About B25.8Overview
What is the ICD-10 code for other cytomegaloviral diseases?
The ICD-10-CM code for other cytomegaloviral diseases is B25.8 (sometimes written as B258). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is B25.8 (Cytomegaloviral disease) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report other cytomegaloviral diseases on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does B25.8 group to?
When other cytomegaloviral diseases is the principal diagnosis on an inpatient stay, it groups to MS-DRG 974, 976, 975, 866, 865, with relative weights from 0.7879 to 3.0488 depending on complications. Higher weights mean higher Medicare reimbursement.
Is B25.8 a CC or MCC?
CMS lists B25.8 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 19 closely related codes in its exclusion list.
Can B25.8 be reported with P35.1?
Not as a rule. The Excludes1 note at B25, which applies to B25.8, lists "congenital cytomegalovirus infection (P35.1)". 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).
What HCC is B25.8?
B25.8 (other cytomegaloviral diseases) maps to CMS-HCC Category 6 (Opportunistic Infections), commonly written as HCC 6, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 6 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 5.
Does B25.8 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, B25.8 adds a risk adjustment factor of about 0.381 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.381 to 0.833 depending on the payment segment). HCC 6 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 6 category page.
