2027 ICD-10-CM Diagnosis Code M24.662Ankylosis, left knee
ICD-10-CM Codes›M00–M99›M20-M25›M24
- Billable — Valid for Submission
- Chronic Condition
M24.662 is a billable ICD-10-CM diagnosis code for ankylosis, left knee. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 553 through 554. Coders also document this condition as ankylosis of bilateral knee joints. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified joint disorders.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Ankylosis of bilateral knee joints
- Ankylosis of left knee joint
- Ankylosis of right knee joint
- Arthrofibrosis of joint of knee
- Arthrofibrosis of left knee
- Arthrofibrosis of right knee
- Bilateral arthrofibrosis fibrosis of knees
- Knee joint ankylosis
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to M24.662: its own notes plus those printed at M24.6, M24, block M00-M25, block M20-M25, and Chapter 13. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- Disorders affecting predominantly peripheral (limb) joints
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- current injury - see injury of joint by body region
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 M24.662, its category, or a range that includes it.
Excludes1 2
These codes carry an Excludes1 note naming M24.662: 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
Ankylosis
fixation and immobility of a joint.
Patient EducationClinical
Joint Disorders
Your joints are places where two or more bones come together. Your shoulders, elbows, hips, knees, and knuckles are all joints. Your spine has joints, too.
The full article covers:
- What are joints?
- What are joint disorders?
- What diseases can affect the joints?
- What types of joint disorders happen from sudden injuries?
- What types of joint disorders happen from overuse?
- How can I keep my joints healthy?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert M24.662 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M24.662Overview
What is the ICD-10 code for ankylosis, left knee?
The ICD-10-CM code for ankylosis, left knee is M24.662 (sometimes written as M24662). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is M24.662 (Ankylosis, knee) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report ankylosis, left knee on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does M24.662 group to?
When ankylosis, left knee is the principal diagnosis on an inpatient stay, it groups to MS-DRG 554, 553, with relative weights from 0.8328 to 1.2492 depending on complications. Higher weights mean higher Medicare reimbursement.
Can M24.662 be reported with a code from M25.6?
Not as a rule. The Excludes1 note at M24.6, which applies to M24.662, lists "stiffness of joint without ankylosis (M25.6-)". 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 M24.662?
Under the General Equivalence Mappings, ankylosis, left knee converts to ICD-9-CM 718.56 (ankylosis-lower/leg). The mapping is approximate, so confirm the match fits the documentation.
