M21.7
Non-Billable

Unequal limb length (acquired)

Non-Billable / Non-Specific Code

What is Unequal limb length (acquired)?

ICD-10-CM M21.7 is the diagnosis code for Unequal limb length (acquired). 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 M21.7

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 M21.7 sits in the ICD-10-CM classification helps ensure proper coding:

Sub-Codes 5 entries
M21.70Unequal limb length (acquired), unspecified siteBillableM21.72Unequal limb length (acquired), humerusNon-BillableM21.721Unequal limb length (acquired), right humerusBillableM21.722Unequal limb length (acquired), left humerusBillableM21.729Unequal limb length (acquired), unspecified humerusBillableM21.73Unequal limb length (acquired), ulna and radiusNon-BillableM21.731Unequal limb length (acquired), right ulnaBillableM21.732Unequal limb length (acquired), left ulnaBillableM21.733Unequal limb length (acquired), right radiusBillableM21.734Unequal limb length (acquired), left radiusBillableM21.739Unequal limb length (acquired), unspecified ulna and radiusBillableM21.75Unequal limb length (acquired), femurNon-BillableM21.751Unequal limb length (acquired), right femurBillableM21.752Unequal limb length (acquired), left femurBillableM21.759Unequal limb length (acquired), unspecified femurBillableM21.76Unequal limb length (acquired), tibia and fibulaNon-BillableM21.761Unequal limb length (acquired), right tibiaBillableM21.762Unequal limb length (acquired), left tibiaBillableM21.763Unequal limb length (acquired), right fibulaBillableM21.764Unequal limb length (acquired), left fibulaBillableM21.769Unequal limb length (acquired), unspecified tibia and fibulaBillable
Related Codes

Frequently Asked Questions

Is M21.7 a billable ICD-10-CM code?

No, M21.7 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.

What does M21.7 mean?

M21.7 is the ICD-10-CM diagnosis code for "Unequal limb length (acquired)". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.

What is the parent code of M21.7?

The parent code of M21.7 is M21 ("Other acquired deformities of limbs"). M21.7 provides a more specific classification within this category.

What section is M21.7 in?

M21.7 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 M21.7?

M21.7 has 5 sub-code(s) that provide more specific detail: M21.70, M21.72, M21.73, M21.75, M21.76.

When should I use M21.7?

Use M21.7 when the patients documented diagnosis matches "Unequal limb length (acquired)" 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 Unequal limb length (acquired)?

The ICD-10-CM code for Unequal limb length (acquired) is M21.7.

Can M21.7 be used for primary diagnosis?

No, M21.7 is non-billable. Use a more specific sub-code for primary diagnosis billing.

What chapter is M21.7 in?

M21.7 is in Chapter 13 of the ICD-10-CM Tabular List.

Is M21.7 valid for 2026?

Yes, M21.7 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.

See Also

← PreviousM21.6X9Other acquired deformities of unspecified footNext →M21.70Unequal limb length (acquired), unspecified site
Code Details
M21.7
Unequal limb length (acquired)
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