| T24.521 | Corrosion of first degree of right knee | NON-BILLABLE CODE |
| T24.521A | Corrosion of first degree of right knee, initial encounter | BILLABLE CODE |
| T24.521D | Corrosion of first degree of right knee, subsequent encounter | BILLABLE CODE |
| T24.521S | Corrosion of first degree of right knee, sequela | BILLABLE CODE |
| T24.522 | Corrosion of first degree of left knee | NON-BILLABLE CODE |
| T24.522A | Corrosion of first degree of left knee, initial encounter | BILLABLE CODE |
| T24.522D | Corrosion of first degree of left knee, subsequent encounter | BILLABLE CODE |
| T24.522S | Corrosion of first degree of left knee, sequela | BILLABLE CODE |
| T24.529 | Corrosion of first degree of unspecified knee | NON-BILLABLE CODE |
| T24.529A | Corrosion of first degree of unspecified knee, initial encounter | BILLABLE CODE |
| T24.529D | Corrosion of first degree of unspecified knee, subsequent encounter | BILLABLE CODE |
| T24.529S | Corrosion of first degree of unspecified knee, sequela | BILLABLE CODE |
