M17.12 – Unilateral Primary Osteoarthritis, Left Knee

Learn about the M17.12 ICD-10-CM code for unilateral primary osteoarthritis of the left knee, its clinical description, synonyms, related codes, and FAQs.

By Audrey Liz Perez on Aug 8, 2025.

Fact Checked by Ericka Pingol.

Use Code

M17.12 diagnosis code: Unilateral primary osteoarthritis, left knee

M17.12 is an ICD-10-CM code for diagnosing unilateral primary osteoarthritis affecting the left knee.
Osteoarthritis is a degenerative joint disease that results from the breakdown of joint cartilage and underlying bone.
The condition is characterized by pain, swelling, stiffness, and limited range of motion in the affected joint.
Risk factors for osteoarthritis include age, obesity, joint injuries, genetics, and prolonged repetitive stress on the joint.
Diagnosis is typically made through clinical examination, patient history, and imaging studies such as X-rays or MRIs.
Please note that this is for unilateral primary osteoarthritis of the left knee. You cannot use this for bilateral secondary osteoarthritis or unilateral secondary osteoarthritis cases of the left knee, nor for the right knee.

Is M17.12 billable?

Yes, M17.12 is a billable ICD-10-CM code that can indicate a diagnosis for reimbursement purposes.

Clinical information

Osteoarthritis is the most common form of arthritis, affecting millions worldwide.
The disease primarily affects weight-bearing joints such as the knees, hips, and spine.
Symptoms often develop gradually and worsen over time, leading to decreased mobility and quality of life.
In severe cases, osteoarthritis treatment options include pain management, physical therapy, weight loss, assistive devices, and joint replacement surgery.
Early intervention and proper management of the condition can help slow down joint degeneration and improve overall function.

Synonyms include

Left knee osteoarthritis
Left knee degenerative joint disease
Left knee OA
Left knee DJD
Left knee arthrosis
Left knee osteoarthritis accompanied by other musculoskeletal system problems
Left knee osteoarthritis with osteoarthritis of other multiple joints

Popular search terms for M17.12

M17.12 ICD-10 code
ICD-10 M17.12
M17.12 diagnosis code
ICD-10 code for unilateral primary osteoarthritis, left knee

Other ICD-10 codes commonly used for unilateral primary osteoarthritis

M17.0: Bilateral primary osteoarthritis of knee
M17.11: Unilateral primary osteoarthritis, right knee
M16.12: Unilateral primary osteoarthritis, left hip
M16.11: Unilateral primary osteoarthritis, right hip
M19.072: Primary osteoarthritis, left ankle and foot
M19.071: Primary osteoarthritis, right ankle and foot
M19.032: Primary osteoarthritis, left wrist
M19.031: Primary osteoarthritis, right wrist
M19.012: Primary osteoarthritis, left shoulder
M19.011: Primary osteoarthritis, right shoulder

Commonly asked questions

M17.12 refers to unilateral primary osteoarthritis affecting the left knee, while M17.11 refers to the same condition affecting the right knee.

Yes, M17.12 is a billable code that can be used for both inpatient and outpatient medical settings to indicate a diagnosis for reimbursement purposes.

The documentation should clearly describe the affected joint, laterality (left knee), and any additional information necessary to support the diagnosis and treatment plan.

EHR and practice management software

Get started for free

*No credit card required

Start for free

Free

$0/usd

Unlimited clients

Telehealth

1GB of storage

Client portal text

Automated billing and online payments