ICD-10 Codes for Knee Pain: Your Go-To Guide
You might have heard a common complaint from most elderly people, and that is often associated with joint pains, and to be more specific, knee pain. A lot of patients in healthcare settings come with knee pain as one of the most frequent musculoskeletal health conditions. This is why it is crucial to be able to accurately code knee pain for medical documentation, insurance reimbursement, and effective patient care.
This blog is an easy-to-read guide for medical coders to understand the ICD-10 code for left knee pain, the ICD-10 code for right knee pain, and how to properly document bilateral knee pain.
What is an ICD-10 code, and what importance does it hold in knee pain?

ICD-10 stands for International Classification of Diseases, 10th Revision, and it is a diagnostic system globally recognized. It is used by medical coders, healthcare providers, and insurance companies to code and classify all the medical diagnoses and symptoms for ease while recording patient health status in claims. It provides standardization of a language used while managing accurate medical patient documentation, precise billing, and effective treatment planning.
Now, let’s talk about knee pain and its ICD-10 code. Like any other crucial information about the patient, it’s of great necessity to handle the ICD-10 codes with caution. Knee pain is a general term and does not provide information about one knee or both knees or which knee. To make things free of confusion, there’s a code for all kinds of knee pain. The right knee pain is referred to by M25.561, the left knee by M25.562, and bilateral knee pain is referred to by these two ICD-10 codes.
The benefits of using the correct codes are:
- A smoother insurance claim process
- Fewer denials and resubmissions
- Better tracking of patient outcomes
- Accurate medical records
One of the main reasons for claim denials is when the providers use unspecified or general codes like M25.569 (pain in unspecified knee). This results in miscommunication with the medical coders and insurers, eventually leading to claim denials. Hence, it’s better to understand when and how to use ICD-10 codes for knee pain for best clinical practice and billing.
Let’s take a deeper dive into the correct ICD-10 codes for knee pain, including laterality-specific codes, how to document bilateral knee pain, and when to use more detailed diagnosis codes, such as for meniscal tears, osteoarthritis, or ligament injuries. This comprehensive resource will be of great aid to one who wants to code with accuracy and confidence.
What Is the ICD-10 Code for Knee Pain?
As mentioned above, the ICD-10 code for unspecified knee pain is M25.56 – Pain in joint, knee. This is used as a general code indicating knee pain without further information, such as in which knee or if both knees. This code is deemed less precise and therefore its use should be limited in cases where more information is present.
Importance of Accurate ICD-10 Coding in Medical Billing
Accuracy in ICD-10 codes is not just a requirement, it’s a responsibility upon every medical coder because it directly impacts:
- Acceptance of claims for insurance reimbursement
- The rationale for treatments and diagnostic tests.
- Patient medical history/records
- Diagnostic categorisation for public health data and research
Specific ICD-10 Codes for Knee Pain
For every possible knee pain scenario, whether it’s the right knee, left knee, or lateral, there is a specific code. The ICD-10 codes for knee pain are as follows:
ICD-10 for knee pain | Description | Explanation |
M25.561 | Pain in the Right Knee | When a patient walks into a clinic with the chief complaint of pain in the right knee, code M25.561 is used. The pain can be due to degenerative disease, trauma, or accident, and is idiopathic. The importance of this code is that it ensures that the claim indicates the specific affected side. |
M25.562 | Pain in Left Knee | This code refers to pain in the left knee. As previously stated, the pain could be due to any cause or condition, such as overuse, arthritis, injury, or post-surgery recovery. The more detail present in the documentation, the stronger the justification for medical necessity and treatment planning. |
M25.569 | Pain in Unspecified Knee | This code is only indicated in situations when:
|
ICD-10 Code for Bilateral Knee Pain
Many clinicians often wonder what code to use for the patient with bilateral knee pain. There isn’t a specific code to indicate bilateral knee pain; rather, a combination of both knees, M25.562 – Pain in Left Knee and M25.561 – Pain in Right Knee, is used.
To justify the imaging, physiotherapy, or surgical evaluations for bilateral knee pain cases, it is crucial to use both codes together accurately in the patient documentation.
Best Tips for Documenting Bilateral Knee Pain
- Documentation (noting onset, severity, and physical findings) of each knee separately.
- Documentation of dual coding when both knees have the same condition, e.g., osteoarthritis.
- Identification of differences between the two knees, e.g., stiffness and swelling level.
Common Causes of Knee Pain and Their ICD-10 Codes
There can be various conditions and reasons behind knee pain. Let’s discuss frequent cases and their relevant ICD-10 codes. These codes offer more detailed diagnostic accuracy as compared to general or codes for unspecified knee pain.
Osteoarthritis of the Knee
Osteoarthritis of the Knee
ICD 10 Code | Description |
M17.0 | Bilateral primary osteoarthritis of the knee |
M17.11 | Unilateral primary osteoarthritis, right knee |
M17.11 | Unilateral primary osteoarthritis, left knee |
M17.9 | Osteoarthritis of the knee, unspecified |
Meniscal Tears
Individuals who twist their knees awkwardly.
ICD 10 Code | Description |
S83.241A | Complex tear of the medial meniscus, current injury, right knee |
S83.242A | Complex tear of the medial meniscus, current injury, left knee |
M23.21 | Derangement of the medial meniscus due to old tear or injury, right knee |
M23.22 | Derangement of medial meniscus, old tear, left knee |
Ligament Injuries
ICD 10 Code | Description |
S83.511A | Sprain of the anterior cruciate ligament of the right knee |
S83.512A | Sprain of the anterior cruciate ligament of the left knee |
S83.421A | Sprain of the medial collateral ligament, right knee |
S83.422A | Sprain of the medial collateral ligament, left knee |
For initial encounters, “A” suffix is used, and for follow up it is replaced with a “D” or “S” as appropriate.
Tips for Accurate ICD-10 Coding

1. Indicate Laterality
Always note down which knee is involved:
- Use M25.561 when right knee pain
- Use M25.562 when left knee pain
- Use both codes when bilateral knee pain
2. Prevent Common Mistakes
- Avoid using unspecified codes (e.g., M25.569) when side-specific details are there.
- Differentiate symptom codes (M25.56x) with diagnosis-specific codes, e.g., M17.xx for osteoarthritis.
- Add seventh characters (A, D, S) when coding post-surgical pain or injuries.
3. Reliable Coding Tools for Medical Coding
The recommended resources for accurate ICD-10 coding are:
- ICD10Data.com
- MD Clarity
- TheraPlatform
- Unbound Medicine & CareCloud
Frequently Asked Questions (FAQs)
How do you document chronic knee pain with an ICD-10 code?
Chronic pain can be documented using the underlying condition by:
- M17.12 – Unilateral Osteoarthritis (left)
- M17.11 – Unilateral Osteoarthritis (right)
- Use M25.561 or M25.562 when no diagnosis has been confirmed.
Can we use M25.26 for both knees?
No. M25.56 is an unspecified code. It is best to use M25.561 and M25.562 in combination to indicate bilateral involvement to improve billing accuracy.
Is there a code for post-op knee pain?
For knee pain that is chronic post-op, G89.28—other chronic postoperative pain—paired with M25.561 or M25.562 and Z98.89—postprocedural status—can be used.
Conclusion
The correct use of ICD-10 codes for knee pain is crucial to ensure accurate billing, support clinical decisions, and indicate the complexity of a patient’s condition. Whether you’re a provider or a medical coder, specificity in the codes is the key element.
Through an in-depth understanding of the appropriate use of codes, the role of laterality, and the value of differentiating between the symptoms and diagnoses, healthcare providers and medical coders can significantly decrease the claim denials and optimize patient care.