ICD-10 · PDGM grouping
B27 Infectious mononucleosis
All 16 codes in the B27 family, with the PDGM clinical group, comorbidity subgroup and primary-position rule CMS assigns, read from the CMS grouper crosswalk v07.2.26 and the CDC FY2027 code file.
Codes in family
16
Can lead a claim
16
Cannot lead a claim
0
What CMS assigns to B27
All 16 codes group to Neuro Rehabilitation (8) and MMTA - Infectious Disease, Neoplasms, and Blood-Forming Diseases (8). None of the 16 is assigned a comorbidity subgroup. Every code can lead a claim.
Every code in B27
Descriptions are CDC’s FY2027 wording; where CMS’s grouper abbreviates one, its form is shown beneath.
| Code | Description | Primary position | Clinical group | Comorbidity subgroup |
|---|---|---|---|---|
| B27.0 Gammaherpesviral mononucleosis | ||||
| B27.00 | Gammaherpesviral mononucleosis without complication | Can lead a claim | K | None |
| B27.01 | Gammaherpesviral mononucleosis with polyneuropathy | Can lead a claim | B | None |
| B27.02 | Gammaherpesviral mononucleosis with meningitis | Can lead a claim | B | None |
| B27.09 | Gammaherpesviral mononucleosis with other complications | Can lead a claim | K | None |
| B27.1 Cytomegaloviral mononucleosis | ||||
| B27.10 | Cytomegaloviral mononucleosis without complications | Can lead a claim | K | None |
| B27.11 | Cytomegaloviral mononucleosis with polyneuropathy | Can lead a claim | B | None |
| B27.12 | Cytomegaloviral mononucleosis with meningitis | Can lead a claim | B | None |
| B27.19 | Cytomegaloviral mononucleosis with other complication | Can lead a claim | K | None |
| B27.8 Other infectious mononucleosis | ||||
| B27.80 | Other infectious mononucleosis without complication | Can lead a claim | K | None |
| B27.81 | Other infectious mononucleosis with polyneuropathy | Can lead a claim | B | None |
| B27.82 | Other infectious mononucleosis with meningitis | Can lead a claim | B | None |
| B27.89 | Other infectious mononucleosis with other complication | Can lead a claim | K | None |
| B27.9 Infectious mononucleosis, unspecified | ||||
| B27.90 | Infectious mononucleosis, unspecified without complication | Can lead a claim | K | None |
| B27.91 | Infectious mononucleosis, unspecified with polyneuropathy | Can lead a claim | B | None |
| B27.92 | Infectious mononucleosis, unspecified with meningitis | Can lead a claim | B | None |
| B27.99 | Infectious mononucleosis, unspecified with other complicationCMS: Infectious mononucleosis, unsp with other complication | Can lead a claim | K | None |
Sources: CMS HH PPS Grouper Software v07.2.26, effective 2026-10-01, for the clinical group, comorbidity subgroup, code-first conventions and primary-position flags; CDC NCHS ICD-10-CM FY2027 code descriptions for the family title and code wording. This is the crosswalk Medicare runs a claim through. Grouping also depends on admission source, timing, the OASIS functional items and the rest of the diagnosis list.
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