| IBD | IBD Differentiation Panel | — |
| IBU | Ibuprofen | — |
| AERA | IgE Receptor Ab | — |
| IGGSCP | IGG Subclasses 1 - 4 with IGG | IGG-Turbidimetry; IGGAL-Quantitative Immunoturbidimetry |
| PCRIG | IGH Gene Rearrangement Analysis | — |
| IGHVM | IGHV Mutation Analysis by Sequencing | — |
| IMI | Imipramine & Desipramine | — |
| IPF | Immature Platelet Fraction | — |
| IBDPE | Immunobullous Disease Panel, Epithelial | — |
| UIEP24R | Immunofixation & Protein Electro, 24 Hr. Urine | — |
| UIEPR | Immunofixation & Protein Electro, Random urine | Urine immunofixation (IFE) on agarose gel; urine protein electrophoresis on agarose media; visual light-chain typing |
| IEPRR | Immunofixation & Serum Protein Electrophoresis | — |
| IFEU | Immunofixation 24 hour urine | — |
| IMFSC | Immunofixation, CSF | — |
| IGA | Immunoglobulin A (IgA) | — |
| IGAS | Immunoglobulin A, Subclasses (1 & 2) | — |
| IGDR | Immunoglobulin D (IgD) | — |
| IMGLBE | Immunoglobulin E (IgE) | — |
| FLCS | Immunoglobulin Free Light Chains, Serum | — |
| IGG | Immunoglobulin G (IgG) | — |
| IGGIS | Immunoglobulin G (IgG) Index & Synthesis Rate | — |
| IGS4 | Immunoglobulin G (IgG) Subclass 4 | — |
| IGSC | Immunoglobulin G (IgG) Subclasses (1,2,3,4) | — |
| IGGC | Immunoglobulin G (IgG), CSF | — |
| IGMRPS | Immunoglobulin M (IgM) | — |
| IGMC | Immunoglobulin M (IgM), CSF | — |
| TLCU | Immunoglobulin Total Light Chains, Urine | — |
| QIGR | Immunoglobulins (IgA, IgG, IgM), Quantitative | — |
| IMMG | Immunoglobulins (IgG, IgA, IgM) | — |
| GAMCSF | Immunoglobulins, CSF Quantitative | — |
| ITS | Immunotyping w/Interpretation, Serum | — |
| IFXPAN | Infliximab & Antibodies to Infliximab Quantitation | — |
| INFXR | Infliximab Quant w/reflex to Antibodies to Infliximab, Serum | — |
| H5PCR | Influenza A (H5) Virus by Qualitative NAAT | — |
| INHIBA | Inhibin A (DIMER) | — |
| IHBNB | Inhibin B | — |
| IE68 | Inner Ear 68KD (Heat Shock Protein 70), IgG | — |
| IEXP | Insecticide Exposure Panel | — |
| INS | Insulin | — |
| INSA | Insulin Antibody | — |
| SOM | Insulin-Like Growth Factor 1 (Somatomedin C) | — |
| IGFBP1 | Insulin-Like Growth Factor Binding Protein 1 (IGFBP-1) | — |
| IGFBP2 | Insulin-Like Growth Factor Binding Protein 2 (IGFBP-2) | — |
| IGF3 | Insulin-Like Growth Factor Binding Protein 3 (IGFBP-3) | — |
| IFT | Insulin, Free and Total | — |
| INSR | Insulin, Random | — |
| IFGF23 | Intact Fibroblast Growth Factor 23 (FGF23), Serum | — |
| IEHCG | Interference Evaluation Heterophile, Beta-Human Chorionic Gonadotroplin, Serum (MAYO via RPS) | — |
| IFGAM | Interferon gamma, Serum | — |
| IL1B | Interleukin 1 beta, Serum | — |
| IL1A | Interleukin 1-Alpha | — |
| IKN10 | Interleukin 10 | — |
| IKN12 | Interleukin 12 | — |
| ILKN2 | Interleukin 2 | — |
| IKN2 | Interleukin 2 Receptor (CD25), Soluble | — |
| ILKN4 | Interleukin 4 | — |
| IL5S | Interleukin 5, Serum | — |
| IKN6 | Interleukin 6 | — |
| INTRF | Intrinsic Factor Blocking Antibody | — |
| IDNEP | Iodine, Serum | — |
| IDNE | Iodine, Urine, Random or 24 Hour | — |
| CAI | Ionized Calcium | — |
| FE | Iron | Colorimetric, Photometric Method |
| IIBC | Iron & Iron Binding Cap | Colorimetric, Photometric Method |
| FEPR | Iron Profile | Colorimetric, Photometric Method, Electrochemiluminescence Immunoassay |
| ISAG2 | Islet Antigen-2 (IA-2) Autoantibody, Serum | — |
| ICAG | Islet Cell Antibody IgG | — |
| ISOT | Isohemagglutinin Titer, IgG & IgM | — |
| ISPA | Isopropanol Alcohol | — |
| ITCNL | Itraconazole | — |
