MCMCB Pro
B99

B99Other and unspecified infectious diseases

Non-billable headerICD-10-CM

B99 is a non-billable header ICD-10-CM code for other and unspecified infectious diseases. It cannot be billed on its own: choose one of the more specific child codes below.

Risk adjustment

B99 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

How B99 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to B99.

  • Arthropathypostinfectious NEC
  • Pneumoniapostinfectional NEC
  • Conjunctivitis NOSininfectious disease NEC
  • Encephalitisininfectious disease NEC
  • Iridocyclitisininfectious disease NOS
  • Mastoiditisininfectious disease NEC
  • Myopathyininfectious disease NEC
  • Neuritisacousticininfectious disease NEC
  • Otitisexternaininfectious disease NEC
  • Polyneuropathyininfectiousdisease NEC
  • Palsycranial nervemultipleininfectious disease

Code to one of these instead B99

2 child codes. Green means billable.

Questions about B99

Is B99 a billable ICD-10-CM code?
No. B99 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does B99 sit in the tabular list?
Certain infectious and parasitic diseases (A00-B99), in the block Other infectious diseases (B99).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.