M23 — Internal derangement of knee
Not billable
Is M23 billable?
No — M23 is a non-billable header code. M23 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 60 billable codes beneath M23.
Billable codes under this header
- M23.40Loose body in knee, unspecified knee
- M23.41Loose body in knee, right knee
- M23.42Loose body in knee, left knee
- M23.50Chronic instability of knee, unspecified knee
- M23.51Chronic instability of knee, right knee
- M23.52Chronic instability of knee, left knee
- M23.90Unspecified internal derangement of unspecified knee
- M23.91Unspecified internal derangement of right knee
- M23.92Unspecified internal derangement of left knee
- M23.000Cystic meniscus, unspecified lateral meniscus, right knee
- M23.001Cystic meniscus, unspecified lateral meniscus, left knee
- M23.002Cystic meniscus, unspecified lateral meniscus, unspecified knee
- M23.003Cystic meniscus, unspecified medial meniscus, right knee
- M23.004Cystic meniscus, unspecified medial meniscus, left knee
- M23.005Cystic meniscus, unspecified medial meniscus, unspecified knee
- M23.006Cystic meniscus, unspecified meniscus, right knee
- M23.007Cystic meniscus, unspecified meniscus, left knee
- M23.009Cystic meniscus, unspecified meniscus, unspecified knee
- M23.011Cystic meniscus, anterior horn of medial meniscus, right knee
- M23.012Cystic meniscus, anterior horn of medial meniscus, left knee
- M23.019Cystic meniscus, anterior horn of medial meniscus, unspecified knee
- M23.021Cystic meniscus, posterior horn of medial meniscus, right knee
- M23.022Cystic meniscus, posterior horn of medial meniscus, left knee
- M23.029Cystic meniscus, posterior horn of medial meniscus, unspecified knee
- M23.031Cystic meniscus, other medial meniscus, right knee
- M23.032Cystic meniscus, other medial meniscus, left knee
- M23.039Cystic meniscus, other medial meniscus, unspecified knee
- M23.041Cystic meniscus, anterior horn of lateral meniscus, right knee
- M23.042Cystic meniscus, anterior horn of lateral meniscus, left knee
- M23.049Cystic meniscus, anterior horn of lateral meniscus, unspecified knee
- M23.051Cystic meniscus, posterior horn of lateral meniscus, right knee
- M23.052Cystic meniscus, posterior horn of lateral meniscus, left knee
- M23.059Cystic meniscus, posterior horn of lateral meniscus, unspecified knee
- M23.061Cystic meniscus, other lateral meniscus, right knee
- M23.062Cystic meniscus, other lateral meniscus, left knee
- M23.069Cystic meniscus, other lateral meniscus, unspecified knee
- M23.200Derangement of unspecified lateral meniscus due to old tear or injury, right knee
- M23.201Derangement of unspecified lateral meniscus due to old tear or injury, left knee
- M23.202Derangement of unspecified lateral meniscus due to old tear or injury, unspecified knee
- M23.203Derangement of unspecified medial meniscus due to old tear or injury, right knee
- M23.204Derangement of unspecified medial meniscus due to old tear or injury, left knee
- M23.205Derangement of unspecified medial meniscus due to old tear or injury, unspecified knee
- M23.206Derangement of unspecified meniscus due to old tear or injury, right knee
- M23.207Derangement of unspecified meniscus due to old tear or injury, left knee
- M23.209Derangement of unspecified meniscus due to old tear or injury, unspecified knee
- M23.211Derangement of anterior horn of medial meniscus due to old tear or injury, right knee
- M23.212Derangement of anterior horn of medial meniscus due to old tear or injury, left knee
- M23.219Derangement of anterior horn of medial meniscus due to old tear or injury, unspecified knee
- 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
- M23.229Derangement of posterior horn of medial meniscus due to old tear or injury, unspecified knee
- M23.231Derangement of other medial meniscus due to old tear or injury, right knee
- M23.232Derangement of other medial meniscus due to old tear or injury, left knee
- M23.239Derangement of other medial meniscus due to old tear or injury, unspecified knee
- M23.241Derangement of anterior horn of lateral meniscus due to old tear or injury, right knee
- M23.242Derangement of anterior horn of lateral meniscus due to old tear or injury, left knee
- M23.249Derangement of anterior horn of lateral meniscus due to old tear or injury, unspecified knee
- M23.251Derangement of posterior horn of lateral meniscus due to old tear or injury, right knee
- M23.252Derangement of posterior horn of lateral meniscus due to old tear or injury, left knee
- M23.259Derangement of posterior horn of lateral meniscus due to old tear or injury, unspecified knee
M23 at a glance
| Code | M23 |
|---|---|
| Description | Internal derangement of knee |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Excludes1 — never code together
The conditions below can never be reported together with M23 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Excludes2 — not included here
The conditions below are not part of M23, but a patient may have both at the same time. When documentation supports it, M23 and the excluded code may both be reported.
Excludes2 — not included here — inherited from Chapter 13
The conditions below are not part of M23, but a patient may have both at the same time. When documentation supports it, M23 and the excluded code may both 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)
Excludes2 — not included here — inherited from M20-M25
The conditions below are not part of M23, but a patient may have both at the same time. When documentation supports it, M23 and the excluded code may both be reported.
- joints of the spine (M40-M54)
What codes fall under M23? (8)
- M23.0Cystic meniscusnot billable
- M23.2Derangement of meniscus due to old tear or injurynot billable
- M23.3Other meniscus derangementsnot billable
- M23.4Loose body in kneenot billable
- M23.5Chronic instability of kneenot billable
- M23.6Other spontaneous disruption of ligament(s) of kneenot billable
- M23.8Other internal derangements of kneenot billable
- M23.9Unspecified internal derangement of kneenot billable
How long has M23 existed?
M23 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.