2027 ICD-10-CM Diagnosis Code M77.9Enthesopathy, unspecified
ICD-10-CM Codes›M00–M99›M70-M79›M77
- Billable — Valid for Submission
- Not Chronic
M77.9 is a billable ICD-10-CM diagnosis code for enthesopathy, unspecified. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Tendon and synovial disorders.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acute calcific periarthritis
- Bilateral enthesopathy of shoulders
- Capsulitis
- Capsulitis of metatarsophalangeal joint of left foot
- Capsulitis of metatarsophalangeal joint of right foot
- Capsulitis of tarsus
- Enthesopathy
- Enthesopathy of foot region
- Enthesopathy of left elbow
- Enthesopathy of left finger
- Enthesopathy of left foot
- Enthesopathy of left hand
- Enthesopathy of left shoulder region
- Enthesopathy of pelvic region
- Enthesopathy of right elbow
- Enthesopathy of right foot
- Enthesopathy of right shoulder region
- Enthesopathy of shoulder region
- Enthesopathy of upper limb
- Enthesopathy of wrist and/or hand
- Periarthritis
- Tarsus enthesopathy
- Tendinitis
- Tendinitis of extensor tendon of left hand
- Tendinitis of extensor tendon of right hand
- Tendinitis of flexor tendon of left hand
- Tendinitis of flexor tendon of right hand
- Tendinitis of left foot
- Tendinitis of right foot
- Tendonitis of bilateral forearms
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to M77.9: 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.
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- Bone spur NOS
- Capsulitis NOS
- Periarthritis NOS
- Tendinitis NOS
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 M77.9, its category, or a range that includes it.
Excludes1 3
These codes carry an Excludes1 note naming M77.9: 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.
Clinical InformationClinical
Enthesopathy
a disorder occurring at the site of insertion of tendons or ligaments into bones or joint capsules.
Patient EducationClinical
Connective Tissue Disorders
Your connective tissue supports many different parts of your body, such as your skin, eyes, and heart. It is like a "cellular glue" that gives your body parts their shape and helps keep them strong. It also helps some of your tissues do their work. It is made of many kinds of proteins. Cartilage and fat are types of connective tissue.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert M77.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M77.9Overview
What is the ICD-10 code for enthesopathy, unspecified?
The ICD-10-CM code for enthesopathy, unspecified is M77.9 (sometimes written as M779). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is M77.9 (Other enthesopathies) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report enthesopathy, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does M77.9 group to?
When enthesopathy, unspecified 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 M77.9 be reported with a code from M71.9?
Not as a rule. The Excludes1 note at M77, which applies to M77.9, 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 M77.9?
Under the General Equivalence Mappings, enthesopathy, unspecified converts to ICD-9-CM 726.90 (enthesopathy, site NOS). The mapping is a direct match.
