M21.90 - Unspecified acquired deformity of unspecified limb

Version 2023

ICD-10:	M21.90
Short Description:	Unspecified acquired deformity of unspecified limb
Long Description:	Unspecified acquired deformity of unspecified limb
Status:	Valid for Submission
Version:	ICD-10-CM 2023
Code Classification:	Diseases of the musculoskeletal system and connective tissue (M00–M99) Other joint disorders (M20-M25) Other acquired deformities of limbs (M21)

1. Approximate Synonyms
2. Tabular List of Diseases and Injuries
3. Index to Diseases and Injuries References
4. Diagnostic Related Groups - MS-DRG Mapping
5. Convert to ICD-9 Code
6. Patient Education
7. Related Codes Browser
8. Code History

M21.90 is a billable ICD-10 code used to specify a medical diagnosis of unspecified acquired deformity of unspecified limb. The code is valid during the fiscal year 2023 from October 01, 2022 through September 30, 2023 for the submission of HIPAA-covered transactions.

Unspecified diagnosis codes like M21.90 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

Acquired deformity of joint of lower limb
Acquired deformity of joint of upper limb
Acquired deformity of limb
Acquired deformity of lower limb
Acquired deformity of the wrist / hand
Acquired deformity of upper limb
Angulation deformity of lower limb
Deformity of fibrous joint
Deformity of limb
Deformity of lower limb
Deformity of upper limb
Joint deformity
Joint deviation
Multiple joint deformity

Index to Diseases and Injuries References

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for this diagnosis code are found in the injuries and diseases index:

- Deformity - Q89.9
- - joint (acquired) NEC - M21.90
- - limb (acquired) - M21.90

Diagnostic Related Groups - MS-DRG Mapping

The is diagnosis code is grouped in the following groups for version MS-DRG V40.0 What are Diagnostic Related Groups?
The Diagnostic Related Groups (DRGs) are a patient classification scheme which provides a means of relating the type of patients a hospital treats. The DRGs divides all possible principal diagnoses into mutually exclusive principal diagnosis areas referred to as Major Diagnostic Categories (MDC). applicable from 10/01/2022 through 09/30/2023.

MS-DRG	MS-DRG Title	MCD	Relative Weight
564	OTHER MUSCULOSKELETAL SYSTEM AND CONNECTIVE TISSUE DIAGNOSES WITH MCC	08	1.5533
565	OTHER MUSCULOSKELETAL SYSTEM AND CONNECTIVE TISSUE DIAGNOSES WITH CC	08	0.9874
566	OTHER MUSCULOSKELETAL SYSTEM AND CONNECTIVE TISSUE DIAGNOSES WITHOUT CC/MCC	08	0.7427

The relative weight of a diagnostic related group determines the reimbursement rate based on the severity of a patient's illness and the associated cost of care during hospitalization.

Convert to ICD-9 Code

Source ICD-10 Code		Target ICD-9 Code
M21.90		736.9 - Acq limb deformity NOS
Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.

Related Codes Browser

ICD Code	Description	Valid for Submission
M21	Other acquired deformities of limbs	NON-BILLABLE CODE
M21.0	Valgus deformity, not elsewhere classified	NON-BILLABLE CODE
M21.00	Valgus deformity, not elsewhere classified, unspecified site	BILLABLE CODE
M21.02	Valgus deformity, not elsewhere classified, elbow	NON-BILLABLE CODE
M21.021	Valgus deformity, not elsewhere classified, right elbow	BILLABLE CODE
M21.022	Valgus deformity, not elsewhere classified, left elbow	BILLABLE CODE
M21.029	Valgus deformity, not elsewhere classified, unspecified elbow	BILLABLE CODE
M21.05	Valgus deformity, not elsewhere classified, hip	NON-BILLABLE CODE
M21.051	Valgus deformity, not elsewhere classified, right hip	BILLABLE CODE
M21.052	Valgus deformity, not elsewhere classified, left hip	BILLABLE CODE
M21.059	Valgus deformity, not elsewhere classified, unspecified hip	BILLABLE CODE
M21.06	Valgus deformity, not elsewhere classified, knee	NON-BILLABLE CODE
M21.061	Valgus deformity, not elsewhere classified, right knee	BILLABLE CODE
M21.062	Valgus deformity, not elsewhere classified, left knee	BILLABLE CODE
M21.069	Valgus deformity, not elsewhere classified, unspecified knee	BILLABLE CODE
M21.07	Valgus deformity, not elsewhere classified, ankle	NON-BILLABLE CODE
M21.071	Valgus deformity, not elsewhere classified, right ankle	BILLABLE CODE
M21.072	Valgus deformity, not elsewhere classified, left ankle	BILLABLE CODE
M21.079	Valgus deformity, not elsewhere classified, unspecified ankle	BILLABLE CODE
M21.1	Varus deformity, not elsewhere classified	NON-BILLABLE CODE
M21.10	Varus deformity, not elsewhere classified, unspecified site	BILLABLE CODE
M21.12	Varus deformity, not elsewhere classified, elbow	NON-BILLABLE CODE
M21.121	Varus deformity, not elsewhere classified, right elbow	BILLABLE CODE
M21.122	Varus deformity, not elsewhere classified, left elbow	BILLABLE CODE
M21.129	Varus deformity, not elsewhere classified, unspecified elbow	BILLABLE CODE
M21.15	Varus deformity, not elsewhere classified, hip	NON-BILLABLE CODE
M21.151	Varus deformity, not elsewhere classified, right hip	BILLABLE CODE
M21.152	Varus deformity, not elsewhere classified, left hip	BILLABLE CODE
M21.159	Varus deformity, not elsewhere classified, unspecified	BILLABLE CODE
M21.16	Varus deformity, not elsewhere classified, knee	NON-BILLABLE CODE
M21.161	Varus deformity, not elsewhere classified, right knee	BILLABLE CODE
M21.162	Varus deformity, not elsewhere classified, left knee	BILLABLE CODE
M21.169	Varus deformity, not elsewhere classified, unspecified knee	BILLABLE CODE
M21.17	Varus deformity, not elsewhere classified, ankle	NON-BILLABLE CODE
M21.171	Varus deformity, not elsewhere classified, right ankle	BILLABLE CODE
M21.172	Varus deformity, not elsewhere classified, left ankle	BILLABLE CODE
M21.179	Varus deformity, not elsewhere classified, unspecified ankle	BILLABLE CODE
M21.2	Flexion deformity	NON-BILLABLE CODE
M21.20	Flexion deformity, unspecified site	BILLABLE CODE
M21.21	Flexion deformity, shoulder	NON-BILLABLE CODE
M21.211	Flexion deformity, right shoulder	BILLABLE CODE
M21.212	Flexion deformity, left shoulder	BILLABLE CODE
M21.219	Flexion deformity, unspecified shoulder	BILLABLE CODE
M21.22	Flexion deformity, elbow	NON-BILLABLE CODE
M21.221	Flexion deformity, right elbow	BILLABLE CODE
M21.222	Flexion deformity, left elbow	BILLABLE CODE
M21.229	Flexion deformity, unspecified elbow	BILLABLE CODE
M21.23	Flexion deformity, wrist	NON-BILLABLE CODE
M21.231	Flexion deformity, right wrist	BILLABLE CODE
M21.232	Flexion deformity, left wrist	BILLABLE CODE
M21.239	Flexion deformity, unspecified wrist	BILLABLE CODE

Code History

FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016 (First year ICD-10-CM implemented into the HIPAA code set)

Previous Code: M21.9

Parent Code: M21.9

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