2027 ICD-10-CM Diagnosis Code M76.51Patellar tendinitis, right knee

ICD-10-CM Codes›M00–M99›M70-M79›M76

ICD-10-CM M76.51
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

M76.51 is a billable ICD-10-CM diagnosis code for patellar tendinitis, right knee. 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

ICD-10-CM Code
M76.51
Billable Status
Yes — Valid for Submission
Code Describes
Patellar tendinitis, right knee
Short Description
Patellar tendinitis, right knee
Same as the full description in the CMS dataset.
Parent Code
M76.5
Patellar tendinitis

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM70-M79Other soft tissue disorders
CategoryM76Enthesopathies, lower limb, excluding foot
This CodeM76.51Patellar tendinitis, right knee

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bilateral tendinitis of knees
  • Bilateral tendinitis of quadriceps tendon
  • Inflammation of ligament
  • Patellar tendonitis
  • Tendinitis of left knee
  • Tendinitis of left patellar tendon
  • Tendinitis of left quadriceps tendon
  • Tendinitis of right knee
  • Tendinitis of right patellar tendon
  • Tendinitis of right quadriceps tendon
  • Tendonitis of bilateral patellar tendons

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to M76.51: its own notes plus those printed at M76 and Chapter 13. A note printed at a category, block or chapter applies to every code under it.

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 M76 Enthesopathies, lower limb, excluding foot applies to 34 codes
  • bursitis due to use, overuse and pressure (M70.-)
  • enthesopathies of ankle and foot (M77.5-)
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.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name M76.51, its category, or a range that includes it.

Excludes1 2

These codes carry an Excludes1 note naming M76.51: they are not reported together with it, unless the two conditions are unrelated.

  • M65.2 Calcific tendinitis
    tendinitis as classified in M75-M77 names M75-M77, which includes this code
  • M71 Other bursopathies
    enthesopathies (M76-M77) names M76-M77, which includes this code

Excludes2 1

These codes carry an Excludes2 note naming M76.51: its condition is not part of those codes, and both may be reported when the patient has both.

  • M70 Soft tissue disorders related to use, overuse and pressure
    enthesopathies (M76-M77) names M76-M77, which includes this code

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

Clinical InformationClinical

  • Enthesopathy

    a disorder occurring at the site of insertion of tendons or ligaments into bones or joint capsules.

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 M76.51 to ICD-9-CMHistory

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

ICD-9-CM
726.64 Patellar tendinitis
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 M76.51Overview

What is the ICD-10 code for patellar tendinitis, right knee?

The ICD-10-CM code for patellar tendinitis, right knee is M76.51 (sometimes written as M7651). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is M76.51 (Patellar tendinitis) a billable code?

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

What MS-DRG does M76.51 group to?

When patellar tendinitis, right knee 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.

What is the ICD-9 equivalent of M76.51?

Under the General Equivalence Mappings, patellar tendinitis, right knee converts to ICD-9-CM 726.64 (patellar tendinitis). The mapping is approximate, so confirm the match fits the documentation.