B99.9 Unspecified infectious disease

Billable ICD-10-CM code, FY2026.

MS-DRG index

Defines the logic of DRG(s) 867-869 in MDC 18.

Approximate ICD-9-CM (GEMs)

• 136.9 Unspecified infectious and parasitic diseases (approximate)

Code annotations containing back-references to B99.9

Back-references to B99

• Code Also: D81.82 Activated Phosphoinositide 3-kinase Delta Syndrome [APDS] ("other infections (A00-B99)")
• Type 2 Excludes: L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified ("specific infections classified to A00-B99")
• Type 2 Excludes: L98.4 Non-pressure chronic ulcer of skin, not elsewhere classified ("specific infections classified to A00-B99")
• Type 2 Excludes: L98.A Non-pressure chronic ulcer of upper limb, not elsewhere classified ("specific infections classified to A00-B99")

Diagnosis Index entries for B99.9

• Disease, diseased › epidemic
• Disease, diseased › infectious, infective
• Fever (inanition) (of unknown origin) (persistent) (with chills) (with rigor) › infective
• Granuloma › infectious
• Infection, infected, infective (opportunistic)

Nearby codes

• B99 Other and unspecified infectious diseases
• B99.8 Other infectious disease
• B99.9 Unspecified infectious disease (this code)