B25.9 — Cytomegaloviral disease, unspecified
Is B25.9 billable?
Yes, but B25.9 is an unspecified code. B25.9 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, B25.9 is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting B25.9 — the more specific alternatives are listed below.
B25.9 at a glance
| Code | B25.9 |
|---|---|
| Description | Cytomegaloviral disease, unspecified |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does B25.9 group to?
B25.9 sits in MDC 18 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 865Viral Illness with MCCmedical
- 866Viral Illness without MCCmedical
As a secondary diagnosis, B25.9 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is B25.9 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to B25.9. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Cytomegalovirus infection
- Disease, diseased › cytomegalic inclusion
- Disease, diseased › cytomegaloviral
- Disease, diseased › inclusion
- Infection, infected, infective › cytomegalovirus, cytomegaloviral (opportunistic)
- Virus, viral › cytomegalovirus
- Disease, diseased › inclusion › salivary gland
- Disease, diseased › salivary gland or duct › inclusion
- Disease, diseased › salivary gland or duct › virus
Excludes1 — never code together — inherited from B25
The conditions below can never be reported together with B25.9 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Use additional code — inherited from Chapter 1
Report an additional code alongside B25.9 to fully describe the condition. B25.9 is sequenced first.
- code to identify resistance to antimicrobial drugs (Z16.-)
Excludes2 — not included here — inherited from Chapter 1
The conditions below are not part of B25.9, but a patient may have both at the same time. When documentation supports it, B25.9 and the excluded code may both 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)
How long has B25.9 existed?
B25.9 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.
Which codes are confused with B25.9?
ICD-10-CM declares these codes mutually exclusive with B25.9 — exactly one of each pair can be correct for a given encounter.