M18.3 – Unilateral post-traumatic osteoarthritis of first carpometacarpal joint

ICD-10-CM 2027 diagnosis code · Osteoarthritis

Non-billable header

ICD-10-CM code M18.3
Code
M18.3 (claims format: M183)
Description
Unilateral post-traumatic osteoarthritis of first carpometacarpal joint
Short description
Unil post-trauma osteoarth of first carpometacarp joint
Billable
No – use a more specific code below
Valid for
Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter
13. Diseases of the musculoskeletal system and connective tissue (M00-M99)
Block
M15-M19 Osteoarthritis
Parent codes
M18

Billable codes under M18.3

M18.3 is a header code and cannot be used on claims. Choose the most specific code:

Notes for M18.3

Applicable to:
  • Post-traumatic osteoarthritis of first carpometacarpal joint NOS

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

Block M15-M19

Excludes2 (not included here):
  • osteoarthritis of spine (M47.-)

Index terms for M18.3

Entries in the ICD-10-CM alphabetic index that lead to this code:

Related codes in M18

Frequently asked questions

What is ICD-10 code M18.3?

M18.3 is the ICD-10-CM code for unilateral post-traumatic osteoarthritis of first carpometacarpal joint, in the block M15-M19 (Osteoarthritis).

Is M18.3 a billable code?

No. M18.3 is a header code with more specific child codes; report one of the billable codes listed above.

What category does M18.3 belong to?

It belongs to category M18 – Osteoarthritis of first carpometacarpal joint.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.