2027 ICD-10-CM Diagnosis Code M65.261Calcific tendinitis, right lower leg
ICD-10-CM Codes›M00–M99›M65-M67›M65
- Billable — Valid for Submission
- Not Chronic
M65.261 is a billable ICD-10-CM diagnosis code for calcific tendinitis, right lower leg. 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 knees. 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.
- Bilateral calcific tendinitis of knees
- Bilateral tendinitis of knees
- Calcific tendinitis of bilateral lower legs
- Calcific tendinitis of knee region
- Calcific tendinitis of left knee
- Calcific tendinitis of left lower leg
- Calcific tendinitis of right knee
- Calcific tendinitis of right lower leg
- Tendinitis of left knee
- Tendinitis of right knee
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to M65.261: 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.
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 M65.261, its category, or a range that includes it.
Excludes1 1
These codes carry an Excludes1 note naming M65.261: 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.
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 M65.261 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M65.261Overview
What is the ICD-10 code for calcific tendinitis, right lower leg?
The ICD-10-CM code for calcific tendinitis, right lower leg is M65.261 (sometimes written as M65261). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is M65.261 (Calcific tendinitis, lower leg) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report calcific tendinitis, right lower leg on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does M65.261 group to?
When calcific tendinitis, right lower leg 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 M65.261 be reported with M75.3?
Not as a rule. The Excludes1 note at M65.2, which applies to M65.261, 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 M65.261?
Under the General Equivalence Mappings, calcific tendinitis, right lower leg converts to ICD-9-CM 727.82 (calcium deposit tendon). The mapping is approximate, so confirm the match fits the documentation.
