2026 ICD-10-CM Diagnosis Code D81.819Biotin-dependent carboxylase deficiency, unspecified

ICD-10-CM Codes›D50–D89›D80-D89›D81

ICD-10-CM D81.819
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D81.819 is a billable ICD-10-CM diagnosis code for biotin-dependent carboxylase deficiency, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 640 through 641. Coders also document this condition as multiple carboxylase deficiency. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Immunity disorders and Other specified and unspecified nutritional and metabolic disorders.

Code Identity

ICD-10-CM Code
D81.819
Billable Status
Yes — Valid for Submission
Code Describes
Biotin-dependent carboxylase deficiency, unspecified
Short Description
Biotin-dependent carboxylase deficiency, unspecified
Same as the full description in the CMS dataset.
Parent Code
D81.81
Biotin-dependent carboxylase deficiency

Code Classification

ChapterD50–D89Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
SectionD80-D89Certain disorders involving the immune mechanism
CategoryD81Combined immunodeficiencies
This CodeD81.819Biotin-dependent carboxylase deficiency, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Multiple carboxylase deficiency

Tabular List NotesGuidance

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

Inclusion Terms

  • Multiple carboxylase deficiency, unspecified

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.

    • Deficiency, deficient
      • biotin-dependent carboxylase
    • Immunodeficiency
      • combined
        • biotin-dependent carboxylase

Clinical ClassificationClinical

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

CCSR BLD008
Immunity disorders
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR END016
Other specified and unspecified nutritional and metabolic disorders
Default principal diagnosis: inpatient No · outpatient No

Clinical InformationClinical

  • Biotinidase Deficiency

    the late onset form of multiple carboxylase deficiency (deficiency of the activities of biotin-dependent enzymes propionyl-coa carboxylase, methylcrotonyl-coa carboxylase, and pyruvate carboxylase) due to a defect or deficiency in biotinidase which is essential for recycling biotin.

  • Holocarboxylase Synthetase Deficiency

    the neonatal form of multiple carboxylase deficiency that is caused by a defect or deficiency in holocarboxylase synthetase. hlcs is the enzyme that covalently links biotin to the biotin dependent carboxylases (propionyl-coa-carboxylase, pyruvate carboxylase, and beta-methylcrotonyl-coa carboxylase).

  • Multiple Carboxylase Deficiency

    a deficiency in the activities of biotin-dependent enzymes (propionyl-coa carboxylase, methylcrotonyl-coa carboxylase, and pyruvate carboxylase) due to one of two defects in biotin metabolism. the neonatal form is due to holocarboxylase synthetase deficiency. the late-onset form is due to biotinidase deficiency.

Patient EducationClinical

Immune System and Disorders

Your immune system is a complex network of cells, tissues, and organs. Together they help the body fight infections and other diseases.

The full article covers:

  • What is the immune system?
  • What are the parts of the immune system?
  • How does the immune system work?
  • What are the types of immunity?
  • What can go wrong with the immune system?

Read the full article at MedlinePlus

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

Convert D81.819 to ICD-9-CMHistory

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

ICD-9-CM
266.2 B-complex defic NEC
Approximate The match is approximate rather than exact.

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 D81.819Overview

Is D81.819 (Biotin-dependent carboxylase deficiency) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report biotin-dependent carboxylase deficiency, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does D81.819 group to?

When biotin-dependent carboxylase deficiency, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 640, 641, with relative weights from 0.7782 to 1.3356 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of D81.819?

Under the General Equivalence Mappings, biotin-dependent carboxylase deficiency, unspecified converts to ICD-9-CM 266.2 (b-complex defic NEC). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.