ICD-10 · PDGM grouping
M21 Other acquired deformities of limbs
All 124 codes in the M21 family, with the PDGM clinical group, comorbidity subgroup and primary-position rule CMS assigns, read from the CMS grouper crosswalk v07.2.26 and the CDC FY2027 code file.
ICD-10-CM FY2027 · CMS grouper v07.2.26
Codes in family
124
Can lead a claim
80
Cannot lead a claim
44
What CMS assigns to M21
80 of the 124 codes group to Musculoskeletal Rehabilitation; 44 are assigned no clinical group. None of the 124 is assigned a comorbidity subgroup. 80 of the 124 can lead a claim.
Every code in M21
Descriptions are CDC’s FY2027 wording; where CMS’s grouper abbreviates one, its form is shown beneath.
| Code | Description | Primary position | Clinical group | Comorbidity subgroup |
|---|---|---|---|---|
| M21.0 Valgus deformity, not elsewhere classified | ||||
| M21.00 | Valgus deformity, not elsewhere classified, unspecified site | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.02 Valgus deformity, not elsewhere classified, elbow | ||||
| M21.021 | Valgus deformity, not elsewhere classified, right elbow | Can lead a claim | E | None |
| M21.022 | Valgus deformity, not elsewhere classified, left elbow | Can lead a claim | E | None |
| M21.029 | Valgus deformity, not elsewhere classified, unspecified elbowCMS: Valgus deformity, not elsewhere classified, unsp elbow | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.05 Valgus deformity, not elsewhere classified, hip | ||||
| M21.051 | Valgus deformity, not elsewhere classified, right hip | Can lead a claim | E | None |
| M21.052 | Valgus deformity, not elsewhere classified, left hip | Can lead a claim | E | None |
| M21.059 | Valgus deformity, not elsewhere classified, unspecified hip | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.06 Valgus deformity, not elsewhere classified, knee | ||||
| M21.061 | Valgus deformity, not elsewhere classified, right knee | Can lead a claim | E | None |
| M21.062 | Valgus deformity, not elsewhere classified, left knee | Can lead a claim | E | None |
| M21.069 | Valgus deformity, not elsewhere classified, unspecified knee | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.07 Valgus deformity, not elsewhere classified, ankle | ||||
| M21.071 | Valgus deformity, not elsewhere classified, right ankle | Can lead a claim | E | None |
| M21.072 | Valgus deformity, not elsewhere classified, left ankle | Can lead a claim | E | None |
| M21.079 | Valgus deformity, not elsewhere classified, unspecified ankleCMS: Valgus deformity, not elsewhere classified, unsp ankle | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.1 Varus deformity, not elsewhere classified | ||||
| M21.10 | Varus deformity, not elsewhere classified, unspecified site | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.12 Varus deformity, not elsewhere classified, elbow | ||||
| M21.121 | Varus deformity, not elsewhere classified, right elbow | Can lead a claim | E | None |
| M21.122 | Varus deformity, not elsewhere classified, left elbow | Can lead a claim | E | None |
| M21.129 | Varus deformity, not elsewhere classified, unspecified elbow | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.15 Varus deformity, not elsewhere classified, hip | ||||
| M21.151 | Varus deformity, not elsewhere classified, right hip | Can lead a claim | E | None |
| M21.152 | Varus deformity, not elsewhere classified, left hip | Can lead a claim | E | None |
| M21.159 | Varus deformity, not elsewhere classified, unspecified hip | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.16 Varus deformity, not elsewhere classified, knee | ||||
| M21.161 | Varus deformity, not elsewhere classified, right knee | Can lead a claim | E | None |
| M21.162 | Varus deformity, not elsewhere classified, left knee | Can lead a claim | E | None |
| M21.169 | Varus deformity, not elsewhere classified, unspecified knee | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.17 Varus deformity, not elsewhere classified, ankle | ||||
| M21.171 | Varus deformity, not elsewhere classified, right ankle | Can lead a claim | E | None |
| M21.172 | Varus deformity, not elsewhere classified, left ankle | Can lead a claim | E | None |
| M21.179 | Varus deformity, not elsewhere classified, unspecified ankle | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.2 Flexion deformity | ||||
| M21.20 | Flexion deformity, unspecified site | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.21 Flexion deformity, shoulder | ||||
| M21.211 | Flexion deformity, right shoulder | Can lead a claim | E | None |
| M21.212 | Flexion deformity, left shoulder | Can lead a claim | E | None |
| M21.219 | Flexion deformity, unspecified shoulder | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.22 Flexion deformity, elbow | ||||
| M21.221 | Flexion deformity, right elbow | Can lead a claim | E | None |
| M21.222 | Flexion deformity, left elbow | Can lead a claim | E | None |
| M21.229 | Flexion deformity, unspecified elbow | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.23 Flexion deformity, wrist | ||||
| M21.231 | Flexion deformity, right wrist | Can lead a claim | E | None |
| M21.232 | Flexion deformity, left wrist | Can lead a claim | E | None |
| M21.239 | Flexion deformity, unspecified wrist | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.24 Flexion deformity, finger joints | ||||
| M21.241 | Flexion deformity, right finger joints | Can lead a claim | E | None |
| M21.242 | Flexion deformity, left finger joints | Can lead a claim | E | None |
| M21.249 | Flexion deformity, unspecified finger joints | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.25 Flexion deformity, hip | ||||
| M21.251 | Flexion deformity, right hip | Can lead a claim | E | None |
| M21.252 | Flexion deformity, left hip | Can lead a claim | E | None |
| M21.259 | Flexion deformity, unspecified hip | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.26 Flexion deformity, knee | ||||
| M21.261 | Flexion deformity, right knee | Can lead a claim | E | None |
| M21.262 | Flexion deformity, left knee | Can lead a claim | E | None |
| M21.269 | Flexion deformity, unspecified knee | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.27 Flexion deformity, ankle and toes | ||||
| M21.271 | Flexion deformity, right ankle and toes | Can lead a claim | E | None |
| M21.272 | Flexion deformity, left ankle and toes | Can lead a claim | E | None |
| M21.279 | Flexion deformity, unspecified ankle and toes | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.3 Wrist or foot drop (acquired) | ||||
| M21.33 Wrist drop (acquired) | ||||
| M21.331 | Wrist drop, right wrist | Can lead a claim | E | None |
| M21.332 | Wrist drop, left wrist | Can lead a claim | E | None |
| M21.339 | Wrist drop, unspecified wrist | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.37 Foot drop (acquired) | ||||
| M21.371 | Foot drop, right foot | Can lead a claim | E | None |
| M21.372 | Foot drop, left foot | Can lead a claim | E | None |
| M21.379 | Foot drop, unspecified foot | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.4 Flat foot [pes planus] (acquired) | ||||
| M21.40 | Flat foot [pes planus] (acquired), unspecified foot | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.41 | Flat foot [pes planus] (acquired), right foot | Can lead a claim | E | None |
| M21.42 | Flat foot [pes planus] (acquired), left foot | Can lead a claim | E | None |
| M21.5 Acquired clawhand, clubhand, clawfoot and clubfoot | ||||
| M21.51 Acquired clawhand | ||||
| M21.511 | Acquired clawhand, right hand | Can lead a claim | E | None |
| M21.512 | Acquired clawhand, left hand | Can lead a claim | E | None |
| M21.519 | Acquired clawhand, unspecified hand | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.52 Acquired clubhand | ||||
| M21.521 | Acquired clubhand, right hand | Can lead a claim | E | None |
| M21.522 | Acquired clubhand, left hand | Can lead a claim | E | None |
| M21.529 | Acquired clubhand, unspecified hand | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.53 Acquired clawfoot | ||||
| M21.531 | Acquired clawfoot, right foot | Can lead a claim | E | None |
| M21.532 | Acquired clawfoot, left foot | Can lead a claim | E | None |
| M21.539 | Acquired clawfoot, unspecified foot | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.54 Acquired clubfoot | ||||
| M21.541 | Acquired clubfoot, right foot | Can lead a claim | E | None |
| M21.542 | Acquired clubfoot, left foot | Can lead a claim | E | None |
| M21.549 | Acquired clubfoot, unspecified foot | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.6 Other acquired deformities of foot | ||||
| M21.61 Bunion | ||||
| M21.611 | Bunion of right foot | Can lead a claim | E | None |
| M21.612 | Bunion of left foot | Can lead a claim | E | None |
| M21.619 | Bunion of unspecified foot | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.62 Bunionette | ||||
| M21.621 | Bunionette of right foot | Can lead a claim | E | None |
| M21.622 | Bunionette of left foot | Can lead a claim | E | None |
| M21.629 | Bunionette of unspecified foot | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.6X Other acquired deformities of foot | ||||
| M21.6X1 | Other acquired deformities of right foot | Can lead a claim | E | None |
| M21.6X2 | Other acquired deformities of left foot | Can lead a claim | E | None |
| M21.6X9 | Other acquired deformities of unspecified foot | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.7 Unequal limb length (acquired) | ||||
| M21.70 | Unequal limb length (acquired), unspecified site | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.72 Unequal limb length (acquired), humerus | ||||
| M21.721 | Unequal limb length (acquired), right humerus | Can lead a claim | E | None |
| M21.722 | Unequal limb length (acquired), left humerus | Can lead a claim | E | None |
| M21.729 | Unequal limb length (acquired), unspecified humerus | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.73 Unequal limb length (acquired), ulna and radius | ||||
| M21.731 | Unequal limb length (acquired), right ulna | Can lead a claim | E | None |
| M21.732 | Unequal limb length (acquired), left ulna | Can lead a claim | E | None |
| M21.733 | Unequal limb length (acquired), right radius | Can lead a claim | E | None |
| M21.734 | Unequal limb length (acquired), left radius | Can lead a claim | E | None |
| M21.739 | Unequal limb length (acquired), unspecified ulna and radius | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.75 Unequal limb length (acquired), femur | ||||
| M21.751 | Unequal limb length (acquired), right femur | Can lead a claim | E | None |
| M21.752 | Unequal limb length (acquired), left femur | Can lead a claim | E | None |
| M21.759 | Unequal limb length (acquired), unspecified femur | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.76 Unequal limb length (acquired), tibia and fibula | ||||
| M21.761 | Unequal limb length (acquired), right tibia | Can lead a claim | E | None |
| M21.762 | Unequal limb length (acquired), left tibia | Can lead a claim | E | None |
| M21.763 | Unequal limb length (acquired), right fibula | Can lead a claim | E | None |
| M21.764 | Unequal limb length (acquired), left fibula | Can lead a claim | E | None |
| M21.769 | Unequal limb length (acquired), unspecified tibia and fibula | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.8 Other specified acquired deformities of limbs | ||||
| M21.80 | Other specified acquired deformities of unspecified limb | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.82 Other specified acquired deformities of upper arm | ||||
| M21.821 | Other specified acquired deformities of right upper arm | Can lead a claim | E | None |
| M21.822 | Other specified acquired deformities of left upper arm | Can lead a claim | E | None |
| M21.829 | Other specified acquired deformities of unspecified upper armCMS: Oth acquired deformities of unspecified upper arm | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.83 Other specified acquired deformities of forearm | ||||
| M21.831 | Other specified acquired deformities of right forearm | Can lead a claim | E | None |
| M21.832 | Other specified acquired deformities of left forearm | Can lead a claim | E | None |
| M21.839 | Other specified acquired deformities of unspecified forearm | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.85 Other specified acquired deformities of thigh | ||||
| M21.851 | Other specified acquired deformities of right thigh | Can lead a claim | E | None |
| M21.852 | Other specified acquired deformities of left thigh | Can lead a claim | E | None |
| M21.859 | Other specified acquired deformities of unspecified thigh | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.86 Other specified acquired deformities of lower leg | ||||
| M21.861 | Other specified acquired deformities of right lower leg | Can lead a claim | E | None |
| M21.862 | Other specified acquired deformities of left lower leg | Can lead a claim | E | None |
| M21.869 | Other specified acquired deformities of unspecified lower legCMS: Oth acquired deformities of unspecified lower leg | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.9 Unspecified acquired deformity of limb and hand | ||||
| M21.90 | Unspecified acquired deformity of unspecified limb | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.92 Unspecified acquired deformity of upper arm | ||||
| M21.921 | Unspecified acquired deformity of right upper arm | Can lead a claim | E | None |
| M21.922 | Unspecified acquired deformity of left upper arm | Can lead a claim | E | None |
| M21.929 | Unspecified acquired deformity of unspecified upper arm | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.93 Unspecified acquired deformity of forearm | ||||
| M21.931 | Unspecified acquired deformity of right forearm | Can lead a claim | E | None |
| M21.932 | Unspecified acquired deformity of left forearm | Can lead a claim | E | None |
| M21.939 | Unspecified acquired deformity of unspecified forearm | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.94 Unspecified acquired deformity of hand | ||||
| M21.941 | Unspecified acquired deformity of hand, right hand | Can lead a claim | E | None |
| M21.942 | Unspecified acquired deformity of hand, left hand | Can lead a claim | E | None |
| M21.949 | Unspecified acquired deformity of hand, unspecified hand | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.95 Unspecified acquired deformity of thigh | ||||
| M21.951 | Unspecified acquired deformity of right thigh | Can lead a claim | E | None |
| M21.952 | Unspecified acquired deformity of left thigh | Can lead a claim | E | None |
| M21.959 | Unspecified acquired deformity of unspecified thigh | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M21.96 Unspecified acquired deformity of lower leg | ||||
| M21.961 | Unspecified acquired deformity of right lower leg | Can lead a claim | E | None |
| M21.962 | Unspecified acquired deformity of left lower leg | Can lead a claim | E | None |
| M21.969 | Unspecified acquired deformity of unspecified lower leg | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
Sources: CMS HH PPS Grouper Software v07.2.26, effective 2026-10-01, for the clinical group, comorbidity subgroup, code-first conventions and primary-position flags; CDC NCHS ICD-10-CM FY2027 code descriptions for the family title and code wording. This is the crosswalk Medicare runs a claim through. Grouping also depends on admission source, timing, the OASIS functional items and the rest of the diagnosis list.
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