M23.5
Non-Billable

Chronic instability of knee

Non-Billable / Non-Specific Code

What is Chronic instability of knee?

ICD-10-CM M23.5 is the diagnosis code for Chronic instability of knee. This code falls under the section "Other joint disorders" within Chapter 13 — Diseases of the musculoskeletal system and connective tissue (M00-M99). It is a non-billable/non-specific ICD-10-CM code that should not be used for reimbursement. A more specific sub-code is required for billing. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.

Coding Guidelines for M23.5

Always refer to the official ICD-10-CM Tabular List for complete coding guidelines. Ensure documentation supports the specificity of the code selected. When in doubt, consult a certified medical coder or the latest CMS guidelines.

ICD-10-CM Code Hierarchy

Understanding where M23.5 sits in the ICD-10-CM classification helps ensure proper coding:

Sub-Codes 3 entries
M23.50Chronic instability of knee, unspecified kneeBillableM23.51Chronic instability of knee, right kneeBillableM23.52Chronic instability of knee, left kneeBillable
Related Codes

Frequently Asked Questions

Is M23.5 a billable ICD-10-CM code?

No, M23.5 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.

What does M23.5 mean?

M23.5 is the ICD-10-CM diagnosis code for "Chronic instability of knee". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.

What is the parent code of M23.5?

The parent code of M23.5 is M23 ("Internal derangement of knee"). M23.5 provides a more specific classification within this category.

What section is M23.5 in?

M23.5 is located in Section M20-M25 — "Other joint disorders" within Chapter 13 of the ICD-10-CM Tabular List.

What are the sub-codes of M23.5?

M23.5 has 3 sub-code(s) that provide more specific detail: M23.50, M23.51, M23.52.

When should I use M23.5?

Use M23.5 when the patients documented diagnosis matches "Chronic instability of knee" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.

People Also Ask

What is the ICD-10 code for Chronic instability of knee?

The ICD-10-CM code for Chronic instability of knee is M23.5.

Can M23.5 be used for primary diagnosis?

No, M23.5 is non-billable. Use a more specific sub-code for primary diagnosis billing.

What chapter is M23.5 in?

M23.5 is in Chapter 13 of the ICD-10-CM Tabular List.

Is M23.5 valid for 2026?

Yes, M23.5 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.

See Also

← PreviousM23.42Loose body in knee, left kneeNext →M23.50Chronic instability of knee, unspecified knee
Code Details
M23.5
Chronic instability of knee
Non-Billable / Non-Specific Code
13 — Diseases of the musculoskeletal system and connective tissue (M00-M99)
M20-M25 — Other joint disorders
2026 ICD-10-CM