M23.221 (Derangement of posterior horn of medial meniscus due to old tear or injury, right knee) compared with M23.222 (Derangement of posterior horn of medial meniscus due to old tear or injury, left knee), from the official CMS tabular data. M23.221 and M23.222 code the same condition on opposite sides.
Same condition; these differ only in which side is documented.
These codes share a category and title and differ only in the side affected. The documentation decides which applies, and a bilateral code is reported only where the code set provides one.
Source: ICD-10-CM tabular list (laterality variant derived from the code title)
Same condition, opposite side. M23.221 and M23.222 name the same condition on opposite sides of the body.
Same category and title, differing only in which side is affected — the documentation decides which one applies, and a bilateral code is reported only where the code set provides one.
| M23.221Derangement of posterior horn of medial meniscus due to old tear or injury, right knee | M23.222Derangement of posterior horn of medial meniscus due to old tear or injury, left knee | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | M00-M99 — Diseases of the musculoskeletal system and connective tissue | M00-M99 — Diseases of the musculoskeletal system and connective tissue |
| Definition | Derangement of posterior horn of medial meniscus due to old tear or injury, right knee is a billable ICD-10-CM diagnosis code (M23.221). | Derangement of posterior horn of medial meniscus due to old tear or injury, left knee is a billable ICD-10-CM diagnosis code (M23.222). |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources