Right knee pain is a common complaint that healthcare professionals see across all age groups. Whether it’s due to minor overuse, a sports-related injury, or simply wear and tear, knee pain must be accurately coded to ensure proper documentation and billing.
In ICD-10, the code for right knee pain is M25.561. While it may seem like a simple symptom code, getting it wrong can result in claim rejections or misrepresentation of the patient’s condition.
This article walks you through everything you need to know about using M25.561 effectively, so you can code confidently.
What Is M25.561?
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ICD-10 Code: M25.561
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Description: Pain in right knee
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Category: M25.5 – Pain in joint
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Used For: Cases where the patient reports knee pain, but no specific diagnosis is confirmed at the time of coding
This is a billable code that should be used when right knee pain is the main complaint, but further evaluation is still ongoing or no structural diagnosis is found.
Why Accurate Coding Matters
As coders, our goal is to tell a clinical story through codes. Using M25.561 appropriately:
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Prevents claim denials
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Complies with payer policies
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Supports medical necessity
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Reflects the patient’s actual condition
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Supports documentation for further evaluation like imaging or physical therapy
When to Use vs. When Not to Use M25.561
| ✅ Use M25.561 When… | ❌ Do NOT Use M25.561 When… |
|---|---|
| Patient presents with right knee pain, no clear diagnosis | A specific condition like arthritis or ligament tear is documented |
| The pain is isolated, and no imaging is done yet | Pain is post-surgical or trauma-related |
| Initial evaluation and provider has not made a diagnosis | Imaging confirms degenerative joint disease or tendonitis |
| Rehabilitation referrals that list “right knee pain” | Provider has already diagnosed bursitis or meniscus tear |
| Pain is documented as chronic but undiagnosed | Pain is due to a confirmed systemic disease like RA |
Clinical Examples
1: No Diagnosis Yet
A 38-year-old complains of right knee pain after jogging. No swelling or injury noted.
Use M25.561
2: Chronic Knee Pain, Still Undiagnosed
A patient has had intermittent right knee pain for 6 months. Imaging is inconclusive.
Use M25.561
Optional pairing: G89.29 (Chronic pain)
3: Therapy Referral
Referral note says “Evaluate and treat right knee pain.” No diagnosis listed.
Use M25.561
Related ICD-10 Codes
Sometimes M25.561 is not the best option. If a diagnosis is confirmed, use a more specific code.
| Condition | ICD-10 Code |
|---|---|
| Osteoarthritis, right knee | M17.11 |
| Prepatellar bursitis | M70.51 |
| Patellar tendinitis | M76.51 |
| ACL tear, right knee | S83.511A |
| Medial meniscus tear | S83.241A |
| Lateral meniscus tear | S83.251A |
| Chronic pain syndrome | G89.4 |
For a full list of ICD-10 codes related to knee injuries and conditions, visit the CDC ICD-10-CM Index.
Documentation Tips
To ensure the use of M25.561 is valid, your provider’s note should clearly document:
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Laterality: Must say “right knee”
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Pain duration: Acute, chronic, intermittent
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Symptoms: Sharp, dull, constant, worsening
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Functional impact: Limping, stiffness, reduced mobility
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No diagnosis yet: No structural or traumatic findings mentioned
If you do not see laterality or pain details in the note, always query the provider for clarification.
Chronic Pain Coding (G89 Series)
When knee pain is chronic and the visit focuses on pain management, add a G89 code with M25.561.
| Scenario | Code Pairing |
|---|---|
| Chronic right knee pain | M25.561 + G89.29 |
| Chronic pain syndrome | M25.561 + G89.4 |
| Post-surgical pain (not M25.561) | Use G89.18 only |
Note: Chronic pain codes require clear documentation of duration (over 3 months), treatment focus, and lack of diagnosis.
Common Mistakes to Avoid
| Mistake | Why It’s a Problem |
|---|---|
| Using M25.56 without laterality | Not billable. You must choose M25.561 or M25.562 |
| Using symptom code when diagnosis is known | Fails coding guidelines and leads to denials |
| Forgetting 7th character for injury codes | Leads to incomplete claim submission |
| Overusing unspecified code M25.569 | Avoid unless laterality is truly not documented |
Frequently Asked Questions
Q1: Can I use M25.561 after a knee replacement surgery?
A: No. Use G89.18 (postoperative pain) instead. Symptom codes like M25.561 are inappropriate for post-op pain.
Q2: What if the provider just says “knee pain”?
A: Use M25.569 for unspecified knee pain. However, it’s better to query for laterality and use M25.561 if possible.
Q3: Can I pair M25.561 with a chronic pain code?
A: Yes, when the pain is documented as chronic and you’re not treating a diagnosed condition. Use G89.29 for general chronic pain.
Q4: Is M25.561 valid in therapy or orthopedic visits?
A: Absolutely, especially if the referral diagnosis is simply “right knee pain” and no cause has been confirmed yet.
Final Thoughts
M25.561 might seem like a basic code, but its correct use tells a precise story. As coders, we must understand:
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Is there a diagnosis?
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Has laterality been documented?
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Is this chronic, acute, or post-surgical?
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Is pain the main reason for the visit?
Coding right knee pain with M25.561 is appropriate only when no specific diagnosis has been established. If a condition is confirmed, always choose a more specific code.
Stay sharp, always query when in doubt, and remember: symptom codes like M25.561 are only as good as the documentation behind them.