| M22 | Disorder of patella | NON-BILLABLE CODE |
| M22.0 | Recurrent dislocation of patella | NON-BILLABLE CODE |
| M22.01 | Recurrent dislocation of patella, right knee | BILLABLE CODE |
| M22.02 | Recurrent dislocation of patella, left knee | BILLABLE CODE |
| M22.1 | Recurrent subluxation of patella | NON-BILLABLE CODE |
| M22.10 | Recurrent subluxation of patella, unspecified knee | BILLABLE CODE |
| M22.11 | Recurrent subluxation of patella, right knee | BILLABLE CODE |
| M22.12 | Recurrent subluxation of patella, left knee | BILLABLE CODE |
| M22.2 | Patellofemoral disorders | NON-BILLABLE CODE |
| M22.2X | Patellofemoral disorders | NON-BILLABLE CODE |
| M22.2X1 | Patellofemoral disorders, right knee | BILLABLE CODE |
| M22.2X2 | Patellofemoral disorders, left knee | BILLABLE CODE |
| M22.2X9 | Patellofemoral disorders, unspecified knee | BILLABLE CODE |
| M22.3 | Other derangements of patella | NON-BILLABLE CODE |
| M22.3X | Other derangements of patella | NON-BILLABLE CODE |
| M22.3X1 | Other derangements of patella, right knee | BILLABLE CODE |
| M22.3X2 | Other derangements of patella, left knee | BILLABLE CODE |
| M22.3X9 | Other derangements of patella, unspecified knee | BILLABLE CODE |
| M22.4 | Chondromalacia patellae | NON-BILLABLE CODE |
| M22.40 | Chondromalacia patellae, unspecified knee | BILLABLE CODE |
| M22.41 | Chondromalacia patellae, right knee | BILLABLE CODE |
| M22.42 | Chondromalacia patellae, left knee | BILLABLE CODE |
| M22.8 | Other disorders of patella | NON-BILLABLE CODE |
| M22.8X | Other disorders of patella | NON-BILLABLE CODE |
| M22.8X1 | Other disorders of patella, right knee | BILLABLE CODE |
| M22.8X2 | Other disorders of patella, left knee | BILLABLE CODE |
| M22.8X9 | Other disorders of patella, unspecified knee | BILLABLE CODE |
| M22.9 | Unspecified disorder of patella | NON-BILLABLE CODE |
| M22.90 | Unspecified disorder of patella, unspecified knee | BILLABLE CODE |
| M22.91 | Unspecified disorder of patella, right knee | BILLABLE CODE |
| M22.92 | Unspecified disorder of patella, left knee | BILLABLE CODE |
