2027 ICD-10-CM Diagnosis Code B85.4Mixed pediculosis and phthiriasis
ICD-10-CM Codes›A00–B99›B85-B89›B85
- Billable — Valid for Submission
- Not Chronic
B85.4 is a billable ICD-10-CM diagnosis code for mixed pediculosis and phthiriasis. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 606 through 607. Coders also document this condition as infestation by Pediculus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Parasitic, other specified and unspecified infections.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Infestation by Pediculus
- Infestation by Phthirus
- Mixed pediculus infestation
- Pediculosis and phthirus infections
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to B85.4: its own notes plus those printed at Chapter 1. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- diseases generally recognized as communicable or transmissible
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- carrier or suspected carrier of infectious disease (Z22.-)
- certain localized infections - see body system-related chapters
- infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
- infectious and parasitic diseases specific to the perinatal period (P35-P39)
- influenza and other acute respiratory infections (J00-J22)
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code to identify resistance to antimicrobial drugs (Z16.-)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 B85.4 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About B85.4Overview
What is the ICD-10 code for mixed pediculosis and phthiriasis?
The ICD-10-CM code for mixed pediculosis and phthiriasis is B85.4 (sometimes written as B854). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is B85.4 (Pediculosis and phthiriasis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report mixed pediculosis and phthiriasis on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does B85.4 group to?
When mixed pediculosis and phthiriasis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 607, 606, with relative weights from 0.8772 to 1.5721 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of B85.4?
Under the General Equivalence Mappings, mixed pediculosis and phthiriasis converts to ICD-9-CM 132.3 (mixed pedicul & phthirus). The mapping is a direct match.
