| YIBD | IBD Differentiation Panel | — |
| YIBU | Ibuprofen | — |
| YAERA | IgE Receptor Ab | Flow Cytometry |
| YIGGSCP | IGG Subclasses 1 - 4 with IGG | IGG-Turbidimetry; IGGAL-Quantitative Immunoturbidimetry |
| YPCRIG | IGH Gene Rearrangement Analysis | — |
| YIGHVM | IGHV Mutation Analysis by Sequencing | — |
| YIMI | Imipramine & Desipramine | — |
| YIPF | Immature Platelet Fraction | — |
| YIBDPE | Immunobullous Disease Panel, Epithelial | — |
| YUIEP24R | Immunofixation & Protein Electro, 24 Hr. Urine | — |
| YUIEPR | Immunofixation & Protein Electro, Random urine | Urine immunofixation (IFE) on agarose gel; urine protein electrophoresis on agarose media; visual light-chain typing |
| YIEPRRR | Immunofixation & Serum Protein Electrophoresis | Immunotyping, Capillary Electrophoresis, Turbidimetry |
| YIFEU | Immunofixation 24 hour urine | — |
| YIMFSC | Immunofixation, CSF | — |
| YIGA | Immunoglobulin A (IgA) | — |
| YIGAS | Immunoglobulin A, Subclasses (1 & 2) | — |
| YIGDR | Immunoglobulin D (IgD) | — |
| YIMGLBE | Immunoglobulin E (IgE) | — |
| YFLCS | Immunoglobulin Free Light Chains, Serum | — |
| YIGG | Immunoglobulin G (IgG) | — |
| YIGGIS | Immunoglobulin G (IgG) Index & Synthesis Rate | — |
| YIGS4 | Immunoglobulin G (IgG) Subclass 4 | — |
| YIGSC | Immunoglobulin G (IgG) Subclasses (1,2,3,4) | — |
| YIGGC | Immunoglobulin G (IgG), CSF | — |
| YIGMRPS | Immunoglobulin M (IgM) | — |
| YIGMC | Immunoglobulin M (IgM), CSF | — |
| YTLCU | Immunoglobulin Total Light Chains, Urine | — |
| YQIGR | Immunoglobulins (IgA, IgG, IgM), Quantitative | — |
| YIMMG | Immunoglobulins (IgG, IgA, IgM) | — |
| YGAMCSF | Immunoglobulins, CSF Quantitative | — |
| YITS | Immunotyping w/Interpretation, Serum | Immunotyping, Capillary Electrophoresis |
| YIFXPAN | Infliximab & Antibodies to Infliximab Quantitation | — |
| YINFXR | Infliximab Quant w/reflex to Antibodies to Infliximab, Serum | — |
| YH5PCR | Influenza A (H5) Virus by Qualitative NAAT | — |
| YINHIBA | Inhibin A (DIMER) | — |
| YIHBNB | Inhibin B | — |
| YIE68 | Inner Ear 68KD (Heat Shock Protein 70), IgG | — |
| YIEXP | Insecticide Exposure Panel | — |
| YINSLN | Insulin | Electrochemiluminescence Immunoassay (ECLIA) |
| YINS | Insulin | Beckman Coulter Access 2 |
| YINSA | Insulin Antibody | — |
| YSOM | Insulin-Like Growth Factor 1 (Somatomedin C) | — |
| YIGFBP1 | Insulin-Like Growth Factor Binding Protein 1 (IGFBP-1) | — |
| YIGFBP2 | Insulin-Like Growth Factor Binding Protein 2 (IGFBP-2) | — |
| YIGF3 | Insulin-Like Growth Factor Binding Protein 3 (IGFBP-3) | — |
| YIFT | Insulin, Free and Total | — |
| YINSR | Insulin, Random | — |
| YIFGF23 | Intact Fibroblast Growth Factor 23 (FGF23), Serum | — |
| YIEHCG | Interference Evaluation Heterophile, Beta-Human Chorionic Gonadotroplin, Serum (MAYO via RPS) | HCGII: Medical Interpretation; HCGQN: Electrochemiluminescent Immunoassay; HCGAM: Immunoenzymatic Assay |
| YIFGAM | Interferon gamma, Serum | — |
| YIL1B | Interleukin 1 beta, Serum | — |
| YIL1A | Interleukin 1-Alpha | — |
| YIKN10 | Interleukin 10 | — |
| YIKN12 | Interleukin 12 | — |
| YIL17 | Interleukin 17, Serum | Quantitative Multiplex Bead Assay |
| YILKN2 | Interleukin 2 | — |
| YIKN2 | Interleukin 2 Receptor (CD25), Soluble | — |
| YILKN4 | Interleukin 4 | — |
| YIL5S | Interleukin 5, Serum | — |
| YIKN6 | Interleukin 6 | — |
| YINTRF | Intrinsic Factor Blocking Antibody | — |
| YIDNEP | Iodine, Serum | Quantitative Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) |
| YIDNE | Iodine, Urine, Random or 24 Hour | — |
| YCAI | Ionized Calcium | Radiometer ABL825 Analyzer |
| YFE | Iron | Colorimetric, Photometric Method |
| YIIBC | Iron & Iron Binding Cap | Colorimetric, Photometric Method |
| YFEPR | Iron Profile | Colorimetric, Photometric Method, Electrochemiluminescence Immunoassay |
| YISAG2 | Islet Antigen-2 (IA-2) Autoantibody, Serum | — |
| YICAG | Islet Cell Antibody IgG | — |
| YISOT | Isohemagglutinin Titer, IgG & IgM | — |
| YISPA | Isopropanol Alcohol | — |
| YITCNL | Itraconazole | — |
