| Test Name (Click to sort by popular result) | COE Code |
| Rabies Antibody | ML MISC |
| Reducing Substances, Stool | REDSTL |
| Renal Function Panel | RENAL |
| Renin | PRA |
| Reptilase Time | REPTILASE |
| Respiratory Culture, Aerobic | RESPG, GSS |
| Respiratory Culture, Aerobic, Cystic Fibrosis | CF, GSS |
| Respiratory Syncytial Virus Antibody, IgG & IgM | SRSV |
| Respiratory Syncytial Virus Antigen | RSVI |
| Respiratory Viruses by PCR | PCRIR |
| Reticulin Antibodies, Serum | RETA |
| Reticulocyte Count | RETIK |
| Rett Syndrome (MECP2) Gene Sequencing | MECSS |
| Rheumatoid Factor | RF |
| Rickettsia rickettsii Antibody, IgG | RMSFG |
| Rickettsia typhi Antibody, IgG | SL MISC |
| Rickettsial Disease Antibody Panel | SL MISC |
| Rifampin | ML MISC |
| Rohypnol | ML MISC |
| Rotavirus Antigen | ROTA |
| Rubella Virus Antibody, IgG | RUBG |
| Rubella Virus Antibody, IgM | |
| Rubeola Virus Antibody, IgG | ROBGE |
| Rubeola Virus Antibody, IgG and IgM, CSF | ML MISC |
| Rubeola Virus Antibody, IgM | ROM |