2026 ICD-10-CM Diagnosis Code B81.1Intestinal capillariasis

ICD-10-CM Codes›A00–B99›B65-B83›B81

ICD-10-CM B81.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B81.1 is a billable ICD-10-CM diagnosis code for intestinal capillariasis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 391 through 392. Coders also document this condition as capillaria aerophila infection. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Parasitic, other specified and unspecified infections.

Code Identity

ICD-10-CM Code
B81.1
Billable Status
Yes — Valid for Submission
Code Describes
Intestinal capillariasis
Short Description
Intestinal capillariasis
Same as the full description in the CMS dataset.
Parent Code
B81
Other intestinal helminthiases, not elsewhere classified

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB65-B83Helminthiases
CategoryB81Other intestinal helminthiases, not elsewhere classified
This CodeB81.1Intestinal capillariasis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Capillaria aerophila infection
  • Capillaria infection
  • Capillaria philippinensis infection

Tabular List NotesGuidance

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

Inclusion Terms

  • Capillariasis NOS
  • Infection due to Capillaria philippinensis

Type 2 Excludes

  • hepatic capillariasis B83.8

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.

    • Capillariasis(intestinal)
    • Diarrhea, diarrheal(disease) (infantile) (inflammatory)
      • due to
        • Capillaria philippinensis
    • Infection, infected, infective(opportunistic)
      • Capillaria (intestinal)
    • Infection, infected, infective(opportunistic)
      • Capillaria (intestinal)
        • philippinensis
    • Infestation
      • Capillaria
        • philippinensis
    • Infestation
      • helminth
        • intestinal
          • capillariasis

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

Parasitic Diseases

Parasites are living things that use other living things - like your body - for food and a place to live. You can get them from contaminated food or water, a bug bite, or sexual contact. Some parasitic diseases are easily treated and some are not.

Read the full article at MedlinePlus

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

Convert B81.1 to ICD-9-CMHistory

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

ICD-9-CM
127.5 Capillariasis
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 B81.1Overview

Is B81.1 (Other intestinal helminthiases, not elsewhere classified) a billable code?

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

What MS-DRG does B81.1 group to?

When intestinal capillariasis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 391, 392, with relative weights from 0.7796 to 1.2683 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of B81.1?

Under the General Equivalence Mappings, intestinal capillariasis converts to ICD-9-CM 127.5 (capillariasis). 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.