2026 ICD-10-CM Diagnosis Code B85.0Pediculosis due to Pediculus humanus capitis

ICD-10-CM Codes›A00–B99›B85-B89›B85

ICD-10-CM B85.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B85.0 is a billable ICD-10-CM diagnosis code for pediculosis due to Pediculus humanus capitis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 606 through 607. Coders also document this condition as dermatosis caused by lice. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Parasitic, other specified and unspecified infections.

Code Identity

ICD-10-CM Code
B85.0
Billable Status
Yes — Valid for Submission
Code Describes
Pediculosis due to Pediculus humanus capitis
Short Description
Pediculosis due to Pediculus humanus capitis
Same as the full description in the CMS dataset.
Parent Code
B85
Pediculosis and phthiriasis

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB85-B89Pediculosis, acariasis and other infestations
CategoryB85Pediculosis and phthiriasis
This CodeB85.0Pediculosis due to Pediculus humanus capitis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Dermatosis caused by lice
  • Infestation by Pediculus
  • Pediculosis capitis

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Head-louse infestation

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Infestation
      • Pediculus
        • capitis (humanus) (any site)
    • Infestation
      • Pediculus
        • head
    • Lice(infestation)
      • head (Pediculus capitis)
    • Pediculosis(infestation)
      • capitis (head-louse) (any site)
    • Pediculosis(infestation)
      • eyelid
    • Plica
      • polonica

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INF009
Parasitic, other specified and unspecified infections
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Head Lice

Head lice are tiny insects that live on people's heads. Adult lice are about the size of sesame seeds. The eggs, called nits, are even smaller - about the size of a dandruff flake. Lice and nits are found on or near the scalp, most often at the neckline and behind the ears.

The full article covers:

  • What are head lice?
  • How do head lice spread?
  • Who is at risk for head lice?
  • What are the symptoms of head lice?
  • How do you know if you have head lice?
  • What are the treatments for head lice?
  • Can head lice be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert B85.0 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
132.0 Pediculus capitis
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About B85.0Overview

Is B85.0 (Pediculosis and phthiriasis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report pediculosis due to Pediculus humanus capitis on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does B85.0 group to?

When pediculosis due to Pediculus humanus capitis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 606, 607, with relative weights from 0.9064 to 1.5132 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of B85.0?

Under the General Equivalence Mappings, pediculosis due to Pediculus humanus capitis converts to ICD-9-CM 132.0 (pediculus capitis). The mapping is a direct match.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.