| 91112 | G6PD |
| 91107 | Gabapentin |
| 91331 | GAD Antibody |
| 2019 | Gamma-glutamyl |
| 91332 | Gamma-Hydroxybutyric Acid, Serum |
| 91327 | Gamma-Hydroxybutyric Acid, Urine |
| 2112 | Garamycin, Peak |
| 2125 | Garamycin, Peak and Trough |
| 2113 | Garamycin, Trough |
| 91108 | Gastrin |
| 91109 | GBM |
| 1130 | GC Aptima |
| 4022 | GC Culture |
| 4032 | Genital Culture |
| 2112 | Gentamicin, Peak |
| 2125 | Gentamicin, Peak and Trough |
| 2113 | Gentamicin, Trough |
| 2019 | GGT |
| 91332 | GHB, Serum |
| 91327 | GHB, Urine |
| 4683 | Giardia Antigen [Human / Vet] |
| 91110 | Gliadin Peptide Antibodies, IgG / IgA |
| 91109 | Glomerular Basement Membrane Antibody, IgG |
| 91111 | Glucagon |
| 91112 | Glucose 6 Phosphate Dehydrogenase |
| 2058 | Glucose Tolerance 2 HR [with 1/2 HR specimen] |
| 2023 | Glucose Tolerance 3 HR [with 1/2 HR specimen] |
| 2024 | Glucose Tolerance 4 HR [with 1/2 HR specimen] |
| 2035 | Glucose Tolerance 5 HR [with 1/2 HR specimen] |
| 2026 | Glucose Tolerance 6 HR [with 1/2 HR specimen] |
| 2093 | Glucose, 1 HR [Post Glucola] |
| 2143 | Glucose, 2 HR Post [Post Prandial, Post Glucola] |
| 2048 | Glucose, CSF |
| 2606 | Glucose, Fasting + 2 HR |
| 1023 | Glucose, Serum or Plasma |
| 2487 | Glucose, Synovial Fluid |
| 2022 | Glucose, Urine Quant |
| 91331 | Glutamic Acid Decarboxylase Antibody |
| 91113 | Gluten Sensitivity Panel |
| 2051 | Glycohemoblobin |
| 91027 | Glycoprotein, Beta 2 |
| 91106 | Glycosylated Serum Proteins |
| 91403 | Gonococcal Antibody |
| 4022 | Gonorrhea Culture |
| 1130 | Gonorrhea, Aptima |
| 4000 | Gram Stain |
| 91248 | Growth Hormone |
| 3765 | Guaiac Test |
| 3779 | Guaic |