What M17 covers · when clinicians use it
ICD-10 code M17 identifies Osteoarthritis of knee in the U.S. ICD-10-CM clinical and billing record set. It sits within the Musculoskeletal System chapter (M00–M99), the section that groups related diagnoses so providers, payers, and public-health agencies report them consistently. Clinicians and medical coders apply M17 when an encounter's findings match the Osteoarthritis of knee description, attaching it to the patient record so downstream insurance claims, payer audits, quality reporting, and epidemiological surveillance all reference the same standardized diagnosis. The ICD-10-CM is maintained by the Centers for Medicare & Medicaid Services and the CDC's National Center for Health Statistics, with an updated official code set released each U.S. fiscal year — always verify M17 against the current CMS/CDC release and your payer's documentation guidance before final use. This page summarizes documentation context for M17 and is a coding reference, not clinical, diagnostic, or billing advice.
M17 refers to Osteoarthritis of knee, a form of degenerative joint disease marked by cartilage breakdown, bone remodeling, and eventual joint stiffness and pain. These conditions are the leading cause of joint disability in adults and older populations.
Symptoms
- Joint pain – Especially with movement or weight-bearing (hips, knees, hands)
- Joint stiffness – Typically after periods of inactivity, improving with use
- Swelling and tenderness – Common in affected joints
- Reduced range of motion – Seen in advanced osteoarthritis (M16, M17, M18)
- Bony enlargements – Nodes at finger joints or visible deformities
Diagnosis
Diagnosis of Osteoarthritis of knee is based on clinical examination, history, and radiologic findings (joint space narrowing, osteophyte formation, subchondral sclerosis). MRI may detect early cartilage changes. Laboratory tests are mainly used to exclude inflammatory arthritis.
ICD10 Code Usage
ICD10 code M17 is used by orthopedic surgeons, rheumatologists, primary care physicians, physical therapists, and rehabilitation teams to guide management, insurance billing, and surgical planning (e.g., joint replacement).
Related Codes
- M15 – Polyosteoarthritis
- M16 – Osteoarthritis of hip
- M18 – Osteoarthritis of first carpometacarpal joint
- M19 – Other and unspecified osteoarthritis
FAQs
Q1: What is ICD10 code M17?
A: It refers to Osteoarthritis of knee, a chronic degenerative disorder causing joint pain, stiffness, and functional limitation due to cartilage loss.
Q2: How does polyosteoarthritis (M15) differ from other codes?
A: M15 involves multiple joints throughout the body, while M16–M18 refer to specific joints like hip, knee, or thumb base.
Q3: Is osteoarthritis only age-related?
A: While age is a major risk factor, injuries, obesity, genetics, and joint overuse also contribute.
Q4: How is osteoarthritis treated?
A: Treatments include weight management, physical therapy, NSAIDs, intra-articular injections, and surgical interventions like joint replacement.
Q5: Who typically manages osteoarthritis?
A: Orthopedic surgeons, rheumatologists, physiotherapists, and primary care providers collaboratively manage osteoarthritis based on severity.
Conclusion
ICD10 code M17 provides essential classification for Osteoarthritis of knee, enabling appropriate treatment planning, surgical decision-making, and disability assessment in patients with degenerative joint disease.