Common ICD-10 Codes for Right Knee Pain: A Comprehensive Guide for Accurate Billing

For a practice to be financially healthy, precise medical coding is absolutely essential. It is especially critical to include the proper ICD-10 code for examples of clinical complaints, if only for the fact that for such an instance right knee pain, it is not only a matter of billing, but also care of the patient. It also involves payment reimbursement related to coding, and there are even important regulations that must be followed for coding. When it comes to reimbursement of claims, making the recipient’s point of view clear with diagnosis coding is beneficial, and if such a diagnosis is absent, it is highly likely that a denial of reimbursement will come and the claim will be denied permanently. In fact, it is critical to prove medical necessity of reimbursement, and diagnosis coding will always ensure that. It is also useful from the standpoint that a patient on record with a given claim is more likely to be tracked for the health of the patient.   For health care providers and specialists, keeping a record of knee pain ICD-10 codes is a useful skill required in the profession and the ICD-10 codes world. Working with the most specific and common codes for knee pain is explained in this guide and is the reason why this guide was created. It offers available examples describing selection and documentation, and best practices to optimize a revenue cycle.

The Cornerstone Code: M25.561 – Right knee pain icd 10

The original pain is in the right knee, and the ICD-10 is M25.561. The ICD-10 is full and correct and is used for primary right knee pain diagnoses, for reimbursement, and to indicate it is a full assessment, as there is no other underlying health condition. The pain is always right and acute for whatever underlying condition the pain to the right knee. Knee Pain ICD-10 Diagnosis Codes Explained (Including Unspecified Pain) When providers document knee pain without identifying laterality or an underlying cause, selecting the correct knee pain ICD-10 diagnosis code becomes critical for claim acceptance. The most common DX code for knee pain is M25.561 for pain in the right knee, while M25.562 applies to left knee pain. If the record simply states “knee pain” without specifying the side, coders must use M25.569 – pain in the unspecified knee, which should be avoided whenever possible. Payers often scrutinize claims using ICD-10 knee pain unspecified, as it signals incomplete documentation. For clean claims, always ensure laterality is clearly documented so the appropriate ICD-10 code for knee pain can be selected. When to Use M25.561: The right knee pain ICD 10 code is used : 

• For early assessments of knee discomfort where a precise origin remains unidentified.
• When the managing diagnosis is pain, regardless of the chronicity.
• For subsequent appointments where pain control continues to be the primary aim of treatment.

Please Note: There are always circumstances where a diagnosis can be historical, in particular codemakers should be looking to the level of the diagnosis more closely. For example, osteoarthritis as a diagnosis by the physician should be coded to M17 –

ICD-10 Code	Description	When to Use
M25.561	Pain in right knee	For documented right knee pain without a more specific underlying diagnosis.
M17.11	Unilateral primary osteoarthritis, right knee	When diagnostic imaging (like X-rays) confirms osteoarthritis as the cause of pain.
S83.5-	Sprain of ligament(s) of knee	For acute traumatic ligament injuries, requiring an additional external cause code.
M25.569	Pain in unspecified knee	A last-resort code used only when the medical record fails to document which knee is affected.

 

Common Specific Diagnoses and Their ICD-10 Codes

Moving beyond general pain, here are the specific codes for prevalent right knee conditions apart from the right knee pain ICD 10 Osteoarthritis (Degenerative Joint Disease) Osteoarthritis is one of the biggest reasons for knee pain. ICD-10 has been very detailed in assigning one code to each type and to each way.

• M17.11 Unilateral primary osteoarthritis, right knee: This code applies when the patient has age-related or \”wear-and-tear\” arthritis and it affects the right knee only.
• M17.31 Unilateral post-traumatic osteoarthritis, right knee: Used when arthritis occurs as a direct result of a knee injury in the past.

  Meniscal Injuries Meniscal tears are a type of knee injury, and there are several codes one must use depending on which meniscus is injured and type of encounter.

• S83.241A – Other tear of medial meniscus, current injury, right knee, initial encounter is a billable code when during the first visit for this problem, that would be the code to use for a new injury to the medial meniscus.
• For subsequent care, one would use the Follow-up Encounter (S83.241D), for long-term effects the code would be Sequela (S83.241S).

  Ligament Sprains (e.g. ACL, MCL) A sprain is defined as the stretching or tearing of a ligament, and codes are stratified depending on which ligament is affected, and which encounter it is.

• S83.511A – Sprain of the right knee’s ACL, initial encounter.
• S83.411A – Sprain of the right knee’s MCL, initial encounter.
• S83.91XA – In the right knee, initial encounter. This code is used when the specific ligament is not provided.

  Patellofemoral Issues & Chondromalacia This sickness deals with the kneecap and the problems with its joints.

• M22.2X1 – Patellofemoral disorders, right knee: This is an even wider range of disorders, such as the disorder classified as pain syndrome.
• M22.41 – Chondromalacia patellae, right knee: This disorder is purely defined as the softening and the deteriorating of the cartilage underneath the kneecap.

Bursitis Inflammation of the fluid-filled sacs (bursae) around the knee.

• M70.51 – Other bursitis of knee, right knee: A common code for bursitis not specified as prepatellar.
• M70.41 – Prepatellar bursitis, right knee: For inflammation of the bursa in front of the kneecap (“housemaid’s knee”).

 ICD-10 Coding for Bilateral Knee Pain Bilateral symptoms require special attention because bilateral knee pain ICD-10 does not have a single dedicated diagnosis code. Instead, coders must report pain in each knee separately using M25.561 (right knee pain) and M25.562 (left knee pain). This approach applies to both acute and chronic bilateral knee pain ICD-10 scenarios. Claims submitted with only one diagnosis code when documentation supports pain in both knees often result in underreported medical necessity. For accurate reimbursement, always code both sides when documenting pain in bilateral knees ICD-10, ensuring the diagnosis fully reflects the patient’s condition.

Essential ICD-10 Coding Guidelines for Knee Pain

Applying these codes correctly requires adherence to key coding conventions.

1. Laterality is Mandatory

ICD-10 emphasizes specificity. Codes for right (M25.561), left (M25.562), and unspecified knee (M25.569) are distinct. Always code to the highest specificity documented.

2. Initial, Subsequent, and Sequela Encounters

For injury codes (S-codes), the 7th character indicates the encounter type:

• A – Initial Encounter: Active treatment for the injury.
• D – Subsequent Encounter: Routine follow-up care during the healing phase.
• S – Sequela: Care for complications or long-term effects of an injury that has healed.

Using the correct 7th character is crucial for accurate billing and reflects the phase of care.

3. Code Also & Use Additional External Cause Codes

When it says “Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury”, it means you must append an external cause code (E-code) to specify the mechanism of the injury (e.g., fall, sports activities). Also, for overuse musculoskeletal conditions, such as bursitis, an activity code (Y93.-) may apply.

4. Codes Being Preceded By and the Excludes Notes

Be sure to note the “Excludes1” and “Excludes2” notes in the Tabular List. Understand that an Excludes1 note means you cannot code the conditions that are detailed together. An Excludes2 note means the condition is not included in the diagnosis, but could be included in coding separately if it is present.

The Impact of Accurate Coding: Beyond Reimbursement

Precise ICD-10 coding does more than just facilitate payment.

• Specific codes justify medical necessity, reducing rejections.
• Accurate data helps track disease prevalence and treatment outcomes.
• Adhering to coding guidelines protects your practice from audit risks and penalties.
• Clean, accurate claims lead to faster reimbursement and improved cash flow.

Knee Swelling, Effusion, and Instability: ICD-10 Coding Consideration

Patients frequently present with symptoms beyond pain, such as swelling, stiffness, or joint instability, which require additional ICD-10 specificity. Knee effusion ICD-10 is reported using M25.461 (right knee effusion), while generalized right knee swelling ICD-10 or swollen right knee ICD-10 may require symptom-based coding if no definitive diagnosis is established. Conditions such as right knee instability ICD-10 and knee stiffness ICD-10 should also be coded separately when documented, as they help justify advanced imaging, injections, or surgical referrals. Capturing these associated findings improves claim accuracy and strengthens medical necessity documentation.

Partner with A2Z Billings for Expert Coding Support

Being good with ICD-10 coding takes a lot of knowledge, and even then, there are a lot of little details to remember. A2Z Billings is here to help you navigate through our medical billing and coding services, alleviating the burden of submitting medical claims. Our certified coders keep up to date with the guidelines, like the new ICD-10-CM guidelines that come into effect October 1, 2025, so you can prioritize the care of your patients.   We can help you make positive billing more of a systemized practice rather than just a headache. Give us a call and make sure your practice is coding for success.