2027 ICD-10-CM Diagnosis Code M65.231Calcific tendinitis, right forearm

ICD-10-CM Codes›M00–M99›M65-M67›M65

ICD-10-CM M65.231
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

M65.231 is a billable ICD-10-CM diagnosis code for calcific tendinitis, right forearm. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 557 through 558. Coders also document this condition as bilateral calcific tendinitis of wrists. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Tendon and synovial disorders.

Code Identity

ICD-10-CM Code
M65.231
Billable Status
Yes — Valid for Submission
Code Describes
Calcific tendinitis, right forearm
Short Description
Calcific tendinitis, right forearm
Same as the full description in the CMS dataset.
Parent Code
Calcific tendinitis, forearm

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM65-M67Disorders of synovium and tendon
CategoryM65Synovitis and tenosynovitis
This CodeM65.231Calcific tendinitis, right forearm

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bilateral calcific tendinitis of wrists
  • Calcific tendinitis of bilateral forearms
  • Calcific tendinitis of left forearm
  • Calcific tendinitis of left wrist
  • Calcific tendinitis of right forearm
  • Calcific tendinitis of right wrist
  • Calcific tendinitis of wrist region
  • Tendinitis of left wrist region
  • Tendinitis of right wrist region
  • Tendonitis of bilateral wrists

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to M65.231: its own notes plus those printed at M65.2, M65, and Chapter 13. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From M65.2 Calcific tendinitis applies to 21 codes
  • tendinitis as classified in M75-M77
  • calcified tendinitis of shoulder (M75.3)
From M65 Synovitis and tenosynovitis applies to 133 codes
  • chronic crepitant synovitis of hand and wrist (M70.0-)
  • current injury - see injury of ligament or tendon by body region
  • soft tissue disorders related to use, overuse and pressure (M70.-)

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.

From Chapter 13 (M00-M99) Diseases of the musculoskeletal system and connective tissue applies to 6,687 codes
  • 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.

From Chapter 13 (M00-M99) Diseases of the musculoskeletal system and connective tissue applies to 6,687 codes
  • 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 M65.231, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming M65.231: they are not reported together with it, unless the two conditions are unrelated.

  • M61.4 Other calcification of muscle
    calcific tendinitis NOS (M65.2-) names M65.2-, which includes this code

Excludes2 1

These codes carry an Excludes2 note naming M65.231: its condition is not part of those codes, and both may be reported when the patient has both.

  • M25 Other joint disorder, not elsewhere classified
    calcification of tendon (M65.2-) names M65.2-, which includes this code

Clinical ClassificationClinical

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

CCSR MUS009
Tendon and synovial disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Tendinitis

Tendons are flexible bands of tissue that connect muscles to bones. They help your muscles move your bones. Tendinitis is the severe swelling of a tendon.

Read the full article at MedlinePlus

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

Convert M65.231 to ICD-9-CMHistory

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

ICD-9-CM
727.82 Calcium deposit tendon
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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About M65.231Overview

What is the ICD-10 code for calcific tendinitis, right forearm?

The ICD-10-CM code for calcific tendinitis, right forearm is M65.231 (sometimes written as M65231). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is M65.231 (Calcific tendinitis, forearm) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report calcific tendinitis, right forearm on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does M65.231 group to?

When calcific tendinitis, right forearm is the principal diagnosis on an inpatient stay, it groups to MS-DRG 557, 558, with relative weights from 0.8873 to 1.4883 depending on complications. Higher weights mean higher Medicare reimbursement.

Can M65.231 be reported with M75.3?

Not as a rule. The Excludes1 note at M65.2, which applies to M65.231, lists "calcified tendinitis of shoulder (M75.3)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

What is the ICD-9 equivalent of M65.231?

Under the General Equivalence Mappings, calcific tendinitis, right forearm converts to ICD-9-CM 727.82 (calcium deposit tendon). The mapping is approximate, so confirm the match fits the documentation.