| G12 | Spinal muscular atrophy and related syndromes | NON-BILLABLE CODE |
| G12.0 | Infantile spinal muscular atrophy, type I [Werdnig-Hoffman] | BILLABLE CODE |
| G12.1 | Other inherited spinal muscular atrophy | BILLABLE CODE |
| G12.2 | Motor neuron disease | NON-BILLABLE CODE |
| G12.20 | Motor neuron disease, unspecified | BILLABLE CODE |
| G12.22 | Progressive bulbar palsy | BILLABLE CODE |
| G12.23 | Primary lateral sclerosis | BILLABLE CODE |
| G12.24 | Familial motor neuron disease | BILLABLE CODE |
| G12.25 | Progressive spinal muscle atrophy | BILLABLE CODE |
| G12.29 | Other motor neuron disease | BILLABLE CODE |
| G12.8 | Other spinal muscular atrophies and related syndromes | BILLABLE CODE |
| G12.9 | Spinal muscular atrophy, unspecified | BILLABLE CODE |
