ICD-10-CM 2027 diagnosis code
M23.309Other meniscus derangements, unspecified meniscus, unspecified knee
M23.309 is a valid, billable ICD-10-CM code for other meniscus derangements, unspecified meniscus, unspecified knee. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Other meniscus derangements, unsp meniscus, unspecified knee
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About M23.309
M23.309 is the ICD-10-CM diagnosis code for other meniscus derangements, unspecified meniscus, unspecified knee. It belongs to category M23 (internal derangement of knee), block M20-M25 (other joint disorders) and chapter 13 (diseases of the musculoskeletal system and connective tissue). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
Within M23.30, choose M23.309 (unspecified knee) only when documentation doesn't support a more specific option: lateral meniscus, right knee (M23.300), lateral meniscus, left knee (M23.301), lateral meniscus, unspecified knee (M23.302), medial meniscus, right knee (M23.303), medial meniscus, left knee (M23.304), medial meniscus, unspecified knee (M23.305), right knee (M23.306) and left knee (M23.307).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 562 (Fracture, Sprain, Strain and Dislocation Except Femur, Hip, Pelvis and Thigh with MCC, relative weight 1.398) and DRG 563 (Fracture, Sprain, Strain and Dislocation Except Femur, Hip, Pelvis and Thigh without MCC, relative weight 0.8985), in MDC 08 (Diseases and Disorders of the Musculoskeletal System and Connective Tissue), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Before ICD-10, this condition was coded in ICD-9-CM as 717.5 (derangement of meniscus, not elsewhere classified).
Notes that apply from higher levels
Instructions written at a parent level also apply to M23.309.
Broader instructions also apply from M20-M25 Other joint disorders and Chapter 13: Diseases of the musculoskeletal system and connective tissue.
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC 08 · Diseases and Disorders of the Musculoskeletal System and Connective Tissue
ICD-9-CM equivalent
Converter →- 717.5Derangement of meniscus, not elsewhere classifiedapproximate
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about M23.309
Is M23.309 billable?
- Yes. M23.309 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can M23.309 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict M23.309 as a principal diagnosis.
Is M23.309 a CC or MCC?
- No. M23.309 is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does M23.309 group to?
- M23.309 is used in the MS-DRG v44.0 logic for MS-DRG 562 (Fracture, Sprain, Strain and Dislocation Except Femur, Hip, Pelvis and Thigh with MCC) and MS-DRG 563 (Fracture, Sprain, Strain and Dislocation Except Femur, Hip, Pelvis and Thigh without MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.
What is the ICD-9 code for M23.309?
- The CMS General Equivalence Mappings map M23.309 to ICD-9-CM 717.5.