| R94 | Abnormal results of function studies | NON-BILLABLE CODE |
| R94.0 | Abnormal results of function studies of central nervous system | NON-BILLABLE CODE |
| R94.01 | Abnormal electroencephalogram [EEG] | BILLABLE CODE |
| R94.09 | Abnormal results of other function studies of central nervous system | BILLABLE CODE |
| R94.1 | Abnormal results of function studies of peripheral nervous system and special senses | NON-BILLABLE CODE |
| R94.11 | Abnormal results of function studies of eye | NON-BILLABLE CODE |
| R94.110 | Abnormal electro-oculogram [EOG] | BILLABLE CODE |
| R94.111 | Abnormal electroretinogram [ERG] | BILLABLE CODE |
| R94.112 | Abnormal visually evoked potential [VEP] | BILLABLE CODE |
| R94.113 | Abnormal oculomotor study | BILLABLE CODE |
| R94.118 | Abnormal results of other function studies of eye | BILLABLE CODE |
| R94.12 | Abnormal results of function studies of ear and other special senses | NON-BILLABLE CODE |
| R94.120 | Abnormal auditory function study | BILLABLE CODE |
| R94.121 | Abnormal vestibular function study | BILLABLE CODE |
| R94.128 | Abnormal results of other function studies of ear and other special senses | BILLABLE CODE |
| R94.13 | Abnormal results of function studies of peripheral nervous system | NON-BILLABLE CODE |
| R94.130 | Abnormal response to nerve stimulation, unspecified | BILLABLE CODE |
| R94.131 | Abnormal electromyogram [EMG] | BILLABLE CODE |
| R94.138 | Abnormal results of other function studies of peripheral nervous system | BILLABLE CODE |
| R94.2 | Abnormal results of pulmonary function studies | BILLABLE CODE |
| R94.3 | Abnormal results of cardiovascular function studies | NON-BILLABLE CODE |
| R94.30 | Abnormal result of cardiovascular function study, unspecified | BILLABLE CODE |
| R94.31 | Abnormal electrocardiogram [ECG] [EKG] | BILLABLE CODE |
| R94.39 | Abnormal result of other cardiovascular function study | BILLABLE CODE |
| R94.4 | Abnormal results of kidney function studies | BILLABLE CODE |
| R94.5 | Abnormal results of liver function studies | BILLABLE CODE |
| R94.6 | Abnormal results of thyroid function studies | BILLABLE CODE |
| R94.7 | Abnormal results of other endocrine function studies | BILLABLE CODE |
| R94.8 | Abnormal results of function studies of other organs and systems | BILLABLE CODE |
