ICDcodes.org
FY2027

M17.9 — Osteoarthritis of knee, unspecified

BillableUnspecified

Is M17.9 billable?

Yes, but M17.9 is an unspecified code. M17.9 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, M17.9 is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting M17.9 — the more specific alternatives are listed below.

M17.9 at a glance

CodeM17.9
DescriptionOsteoarthritis of knee, unspecified
BillableYes
Code setICD-10-CM FY2027
Valid for encountersOctober 1, 2026 – September 30, 2027

Which MS-DRGs does M17.9 group to?

M17.9 sits in MDC 08 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.

  • 553Bone Diseases and Arthropathies with MCCmedical
  • 554Bone Diseases and Arthropathies without MCCmedical

How is M17.9 listed in the Alphabetic Index?

These are the routes through the Alphabetic Index that lead to M17.9. They show the wording a clinician may have documented, which often differs from the Tabular description.

  • Osteoarthritis › knee

Excludes2 — not included here — inherited from Chapter 13

The conditions below are not part of M17.9, but a patient may have both at the same time. When documentation supports it, M17.9 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 M15-M19

The conditions below are not part of M17.9, but a patient may have both at the same time. When documentation supports it, M17.9 and the excluded code may both be reported.

  • osteoarthritis of spine (M47.-)

How long has M17.9 existed?

M17.9 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.

Which conditions are coded to M17.9?

What other codes are in the M17 family? (6)