B27.09 — Gammaherpesviral mononucleosis with other complications
Is B27.09 billable?
Yes — B27.09 is billable for FY2027. B27.09 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. B27.09 may be submitted for encounters from October 1, 2026 through September 30, 2027.
B27.09 at a glance
| Code | B27.09 |
|---|---|
| Description | Gammaherpesviral mononucleosis with other complications |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does B27.09 group to?
B27.09 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
How is B27.09 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to B27.09. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Adenitis › epidemic, acute
- Adenitis › infectious
- Hepatomegaly › in mononucleosis › gammaherpesviral
- Mononucleosis, infectious › Epstein-Barr › with › complication NEC
- Mononucleosis, infectious › gammaherpesviral › with › complication NEC
Inclusion terms
Alternative wording in documentation that is classified to B27.09.
- Hepatomegaly in gammaherpesviral mononucleosis
Use additional code — inherited from Chapter 1
Report an additional code alongside B27.09 to fully describe the condition. B27.09 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 B27.09, but a patient may have both at the same time. When documentation supports it, B27.09 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 B27.09 existed?
B27.09 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.