2027 ICD-10-CM Diagnosis Code M67.321Transient synovitis, right elbow

ICD-10-CM Codes›M00–M99›M65-M67›M67

ICD-10-CM M67.321
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

M67.321 is a billable ICD-10-CM diagnosis code for transient synovitis, right elbow. 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 arthritis of elbows. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Tendon and synovial disorders.

Code Identity

ICD-10-CM Code
M67.321
Billable Status
Yes — Valid for Submission
Code Describes
Transient synovitis, right elbow
Short Description
Transient synovitis, right elbow
Same as the full description in the CMS dataset.
Parent Code
M67.32
Transient synovitis, elbow

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM65-M67Disorders of synovium and tendon
CategoryM67Other disorders of synovium and tendon
This CodeM67.321Transient synovitis, right elbow

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bilateral arthritis of elbows
  • Synovitis of elbow
  • Synovitis of joint of left elbow
  • Synovitis of joint of right elbow
  • Transient arthropathy of elbow joint
  • Transient synovitis of bilateral elbows
  • Transient synovitis of elbow
  • Transient synovitis of left elbow
  • Transient synovitis of right elbow

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to M67.321: its own notes plus those printed at M67.3, M67, 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 M67.3 Transient synovitis applies to 24 codes
  • palindromic rheumatism (M12.3-)
From M67 Other disorders of synovium and tendon applies to 143 codes
  • palmar fascial fibromatosis [Dupuytren] (M72.0)
  • tendinitis NOS (M77.9-)
  • xanthomatosis localized to tendons (E78.2)

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.

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

Elbow Injuries and Disorders

Your elbow joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the elbow joint move. When any of these structures is hurt or diseased, you have elbow problems.

Read the full article at MedlinePlus

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

Convert M67.321 to ICD-9-CMHistory

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

ICD-9-CM
727.09 Synovitis 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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About M67.321Overview

What is the ICD-10 code for transient synovitis, right elbow?

The ICD-10-CM code for transient synovitis, right elbow is M67.321 (sometimes written as M67321). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is M67.321 (Transient synovitis, elbow) a billable code?

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

What MS-DRG does M67.321 group to?

When transient synovitis, right elbow 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 M67.321 be reported with a code from M12.3?

Not as a rule. The Excludes1 note at M67.3, which applies to M67.321, lists "palindromic rheumatism (M12.3-)". 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 M67.321?

Under the General Equivalence Mappings, transient synovitis, right elbow converts to ICD-9-CM 727.09 (synovitis NEC). The mapping is approximate, so confirm the match fits the documentation.