Non-Billable / Non-Specific Code
ICD-10-CM M21 is the diagnosis code for Other acquired deformities of limbs. This code falls under the section "Other joint disorders" within Chapter 13 â 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.
The following conditions should never be coded at the same time as M21. They are mutually exclusive:
The following conditions are not included in M21. If the patient has both, code each condition separately:
Understanding where M21 sits in the ICD-10-CM classification helps ensure proper coding:
No, M21 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.
M21 is the ICD-10-CM diagnosis code for "Other acquired deformities of limbs". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
M21 is located in Section M20-M25 â "Other joint disorders" within Chapter 13 of the ICD-10-CM Tabular List.
M21 has 10 sub-code(s) that provide more specific detail: M21.0, M21.1, M21.2, M21.3, M21.4 and more.
Use M21 when the patients documented diagnosis matches "Other acquired deformities of limbs" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.
The ICD-10-CM code for Other acquired deformities of limbs is M21.
No, M21 is non-billable. Use a more specific sub-code for primary diagnosis billing.
M21 is in Chapter 13 of the ICD-10-CM Tabular List.
Type 1 Excludes for M21 include: acquired absence of limb (Z89.-); congenital absence of limbs (Q71-Q73); congenital deformities and malformations of limbs (Q65-Q66, Q68-Q74).
Yes, M21 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.