ICD-10 Code B88.9 – Infestation, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B88.9 – Infestation, unspecified
What it is
B88.9 is used when the record documents an infestation, but the specific organism or cause is not identified. It covers parasitic or ectoparasitic involvement when details are insufficient for a more specific code.
Clinical signs
Clinical features vary; refer to documentation. Common charted findings may include itching, visible organisms, skin irritation, or patient-reported exposure, but you should code only what is supported in the note.
When to use this code
Use B88.9 when the clinician documents “infestation” without naming the parasite, mite, or other agent. It also fits cases where the note confirms an infestation but the organism is not specified in the available record. If the documentation identifies the cause, choose the more specific code instead.
Do not use for
Do not use B88.9 when the organism is identified and a specific ICD-10 code exists. Do not use it for symptoms alone, such as itching or rash, without documentation of infestation.
Coding tip
Review the assessment and impression carefully; if the organism is named, code the specific infestation rather than B88.9.