2027 ICD-10-CM Diagnosis Code M18.0Bilateral primary osteoarthritis of first carpometacarpal joints
ICD-10-CM Codes›M00–M99›M15-M19›M18
- Billable — Valid for Submission
- Chronic Condition
M18.0 is a billable ICD-10-CM diagnosis code for bilateral primary osteoarthritis of first carpometacarpal joints. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 553 through 554. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Osteoarthritis.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Arthritis of bilateral first carpometacarpal joints
- Arthritis of first carpometacarpal joint of left hand
- Arthritis of first carpometacarpal joint of right hand
- Bilateral osteoarthritis of first carpometacarpal joint
- Bilateral wrist osteoarthritis
- Degenerative joint disease of thumb
- Osteoarthritis of first carpometacarpal joint of left hand
- Osteoarthritis of first carpometacarpal joint of right hand
- Osteoarthritis of joint of bilateral hands
- Osteoarthritis of joint of left hand
- Osteoarthritis of joint of left wrist
- Osteoarthritis of joint of right hand
- Osteoarthritis of joint of right wrist
- Osteoarthrosis of the carpometacarpal joint of the thumb
- Primary arthrosis of first carpometacarpal joints, bilateral
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to M18.0: its own notes plus those printed at block M00-M25, block M15-M19, and Chapter 13. 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.
- Disorders affecting predominantly peripheral (limb) joints
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.
- osteoarthritis of spine (M47.-)
- arthropathic psoriasis (L40.5-)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- compartment syndrome (traumatic) (T79.A-)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Notes
General instructions on how these codes are used.
- Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name M18.0, its category, or a range that includes it.
Excludes1 5
These codes carry an Excludes1 note naming M18.0: they are not reported together with it, unless the two conditions are unrelated.
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
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 M18.0 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M18.0Overview
What is the ICD-10 code for bilateral primary osteoarthritis of first carpometacarpal joints?
The ICD-10-CM code for bilateral primary osteoarthritis of first carpometacarpal joints is M18.0 (sometimes written as M180). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is M18.0 (Osteoarthritis of first carpometacarpal joint) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report bilateral primary osteoarthritis of first carpometacarpal joints on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does M18.0 group to?
When bilateral primary osteoarthritis of first carpometacarpal joints is the principal diagnosis on an inpatient stay, it groups to MS-DRG 554, 553, with relative weights from 0.8328 to 1.2492 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of M18.0?
Under the General Equivalence Mappings, bilateral primary osteoarthritis of first carpometacarpal joints converts to ICD-9-CM 715.14 (loc prim osteoarth-hand). The mapping is approximate, so confirm the match fits the documentation.
