2027 ICD-10-CM Diagnosis Code M77.21Periarthritis, right wrist
ICD-10-CM Codes›M00–M99›M70-M79›M77
- Billable — Valid for Submission
- Not Chronic
M77.21 is a billable ICD-10-CM diagnosis code for periarthritis, right wrist. 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 periarthritis of bilateral wrists. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified connective tissue disease.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Periarthritis of bilateral wrists
- Periarthritis of left wrist
- Periarthritis of right wrist
- Periarthritis of wrist
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to M77.21: its own notes plus those printed at M77 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.
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.
- 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 M77.21, its category, or a range that includes it.
Excludes1 2
These codes carry an Excludes1 note naming M77.21: they are not reported together with it, unless the two conditions are unrelated.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Periarthritis
inflammation of the tissues around a joint. (dorland, 27th ed)
Patient EducationClinical
Wrist Injuries and Disorders
Your wrist connects your hand to your forearm. It is not one big joint; it has several small joints. This makes it flexible and allows you to move your hand in different ways. The wrist has two big forearm bones and eight small bones known as carpals. It also has tendons and ligaments, which are connective tissues.
The full article covers:
- What are the types of wrist injuries and disorders?
- Who is at risk for wrist injuries and disorders?
- What are the symptoms of wrist injuries and disorders?
- How are wrist injuries and disorders diagnosed?
- What are the treatments for wrist injuries and disorders?
- Can wrist injuries and disorders be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert M77.21 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M77.21Overview
What is the ICD-10 code for periarthritis, right wrist?
The ICD-10-CM code for periarthritis, right wrist is M77.21 (sometimes written as M7721). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is M77.21 (Periarthritis of wrist) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report periarthritis, right wrist on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does M77.21 group to?
When periarthritis, right wrist 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 M77.21 be reported with a code from M71.9?
Not as a rule. The Excludes1 note at M77, which applies to M77.21, lists "bursitis NOS (M71.9-)". 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 M77.21?
Under the General Equivalence Mappings, periarthritis, right wrist converts to ICD-9-CM 726.4 (enthesopathy of wrist). The mapping is approximate, so confirm the match fits the documentation.
