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ICD10

ICD-10 Code B99: Other and unspecified infectious diseases

B99 is an ICD-10 diagnosis entry used to group records related to Other and unspecified infectious diseases. You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen. ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Certain infectious and parasitic diseases (A00-B99).

What is this code?

ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Certain infectious and parasitic diseases (A00-B99).

When is it used?

  • May be used when a clinician documents other and unspecified infectious diseases in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
  • This entry may represent a broader category rather than the most specific billable code.

Code hierarchy

chapter
1Certain infectious and parasitic diseases (A00-B99)
block
B99Other infectious diseases (B99)
currentB99

Where you may see this code

You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.

Related specialists

Infectious Disease SpecialistGeneral Physician

Coding guidelines

Compatibility

Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.
Legacy codes
B99
Replacement codes
B99.8 — Other infectious diseaseB99.9 — Unspecified infectious disease

Common synonyms

Other and unspecified infectious diseasesOther and infectious diseases

Frequently asked questions

Code details

CodeB99
SystemICD10
Display nameOther and unspecified infectious diseases
ChapterCertain infectious and parasitic diseases (A00-B99)
BlockOther infectious diseases (B99)

Flags

BillableNo
Valid clinical useNo

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
ArthropathyConjunctivitis(staphylococcal) (streptococcal)NOSEncephalitis(chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute)IridocyclitisMastoiditis(coalescent) (hemorrhagic) (suppurative)MyopathyNeuritis(rheumatoid)Otitis(acute)PalsyPneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)Polyneuropathy(peripheral)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.