2026 ICD-10-CM Diagnosis Code M18.30Unilateral post-traumatic osteoarthritis of first carpometacarpal joint, unspecified hand

ICD-10-CM Codes›M00–M99›M15-M19›M18

ICD-10-CM M18.30
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M18.30 is a billable ICD-10-CM diagnosis code for unilateral post-traumatic osteoarthritis of first carpometacarpal joint, unspecified hand. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 553 through 554. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Osteoarthritis.

Code Identity

ICD-10-CM Code
M18.30
Billable Status
Yes — Valid for Submission
Code Describes
Unilateral post-traumatic osteoarthritis of first carpometacarpal joint, unspecified hand
Short Description
Unil post-trauma osteoarth of 1st carpometacarp jt,unsp hand
Parent Code
M18.3
Unilateral post-traumatic osteoarthritis of first carpometacarpal joint

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM15-M19Osteoarthritis
CategoryM18Osteoarthritis of first carpometacarpal joint
This CodeM18.30Unilateral post-traumatic osteoarthritis of first carpometacarpal joint, unspecified hand

Clinical ClassificationClinical

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

CCSR MUS006
Osteoarthritis
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Osteoarthritis

Osteoarthritis, sometimes called OA, is a type of arthritis that only affects the joints, usually in the hands, knees, hips, neck, and lower back. It's the most common type of arthritis.

The full article covers:

  • What is osteoarthritis?
  • What are the symptoms of osteoarthritis?
  • What causes osteoarthritis?
  • Who is more likely to develop osteoarthritis?
  • How is osteoarthritis diagnosed?
  • What are the treatments for osteoarthritis?

Read the full article at MedlinePlus

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

Convert M18.30 to ICD-9-CMHistory

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

ICD-9-CM
715.24 Loc 2nd osteoarthro-hand
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 M18.30Overview

Is M18.30 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unilateral post-traumatic osteoarthritis of first carpometacarpal joint, unspecified hand on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M18.30 group to?

When unilateral post-traumatic osteoarthritis of first carpometacarpal joint, unspecified hand is the principal diagnosis on an inpatient stay, it groups to MS-DRG 553, 554, with relative weights from 0.8301 to 1.2963 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M18.30?

Under the General Equivalence Mappings, unilateral post-traumatic osteoarthritis of first carpometacarpal joint, unspecified hand converts to ICD-9-CM 715.24 (loc 2nd osteoarthro-hand). 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.