| Kappa light chains in situ hybridization (ISH) | 12376 - Technical only, 12379 - Technical & interpretation |
| Kappa/Lambda quant, blood | |
| Karius Test | 994 |
| Ketones, urine | 334 |
| Ki-67 image by IHC | 12376 - Technical only, 12379 - Technical & Interpretation |
| Kidney bean, IgE | 13461 |
| Kidney stone urine/saturation | 13502 |
| Kidney Transplant Future Serology - transplant donor or recipient | 15149 |
| KIT Asp816Val mutation analysis | 994 |
| Kiwi fruit, IgE | 13454 |
| Kleihauer (Fetal cell) | 457 |
| Kochia, IgE | 994 |
| KOH prep, other sources | 6524 |
| KOH prep, skin, hair & nails | 4348 |
| Kratom screen and confirmation, urine | 994 |