2026 ICD-10-CM Diagnosis Code K38.1Appendicular concretions

ICD-10-CM Codes›K00–K95›K35-K38›K38

ICD-10-CM K38.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

K38.1 is a billable ICD-10-CM diagnosis code for appendicular concretions. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 393 through 395. Coders also document this condition as concretion of appendix. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Appendicitis and other appendiceal conditions.

Code Identity

ICD-10-CM Code
K38.1
Billable Status
Yes — Valid for Submission
Code Describes
Appendicular concretions
Short Description
Appendicular concretions
Same as the full description in the CMS dataset.
Parent Code
K38
Other diseases of appendix

Code Classification

ChapterK00–K95Diseases of the digestive system
SectionK35-K38Diseases of appendix
CategoryK38Other diseases of appendix
This CodeK38.1Appendicular concretions

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Concretion of appendix
  • Concretion of intestine
  • Fecolith in appendix

Tabular List NotesGuidance

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

Inclusion Terms

  • Fecalith of appendix
  • Stercolith of appendix

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.

    • Calculus, calculi, calculous
      • appendix
    • Concretion
      • appendicular
    • Fecalith(impaction)
      • appendix
    • Stercolith(impaction)
      • appendix

Clinical ClassificationClinical

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

CCSR DIG009
Appendicitis and other appendiceal conditions
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Colonic Diseases

Your colon, also known as the large intestine, is part of your digestive system. It's a long, hollow tube at the end of your digestive tract where your body makes and stores stool. Many disorders affect the colon's ability to work properly. Some of these include:

Read the full article at MedlinePlus

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

Convert K38.1 to ICD-9-CMHistory

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

ICD-9-CM
543.9 Diseases of appendix 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 K38.1Overview

Is K38.1 (Other diseases of appendix) a billable code?

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

What MS-DRG does K38.1 group to?

When appendicular concretions is the principal diagnosis on an inpatient stay, it groups to MS-DRG 393, 394, 395, with relative weights from 0.6490 to 1.5993 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of K38.1?

Under the General Equivalence Mappings, appendicular concretions converts to ICD-9-CM 543.9 (diseases of appendix 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.