2027 ICD-10-CM Diagnosis Code M65.00Abscess of tendon sheath, unspecified site
ICD-10-CM Codes›M00–M99›M65-M67›M65
- Billable — Valid for Submission
- Not Chronic
M65.00 is a billable ICD-10-CM diagnosis code for abscess of tendon sheath, unspecified site. 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 abscess of tendon. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Musculoskeletal abscess and Tendon and synovial disorders.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Abscess of tendon
- Abscess of tendon of lower limb
- Abscess of tendon of upper limb
- Abscess of tendon sheath
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to M65.00: its own notes plus those printed at M65.0, 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.
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)
Use Additional Code
Add a second code, after this one, to fully describe the condition.
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.
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.
Patient EducationClinical
Abscess
An abscess is a pocket of pus. You can get an abscess almost anywhere in your body. When an area of your body becomes infected, your body's immune system tries to fight the infection. White blood cells go to the infected area, collect within the damaged tissue, and cause inflammation. During this process, pus forms.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert M65.00 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M65.00Overview
What is the ICD-10 code for abscess of tendon sheath, unspecified site?
The ICD-10-CM code for abscess of tendon sheath, unspecified site is M65.00 (sometimes written as M6500). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is M65.00 (Abscess of tendon sheath) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report abscess of tendon sheath, unspecified site on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does M65.00 group to?
When abscess of tendon sheath, unspecified site 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 M65.00 be reported with a code from M70.0?
Not as a rule. The Excludes1 note at M65, which applies to M65.00, lists "chronic crepitant synovitis of hand and wrist (M70.0-)". 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).
