| UGT1A1 Irinotecan toxicity | 994 |
| Ulocladium chartartum, IgE | 994 |
| Urea nitrogen, body fluid | 994 |
| Urea nitrogen, timed urine | 264 |
| Ureaplasma species, molecular detection, PCR, plasma | 994 |
| Urethral culture, stain | 625 |
| Uric acid | 262 |
| Uric acid, body fluid | 994 |
| Uric acid, rasburicase | 8290 |
| Uric acid, timed urine | 263 |
| Urinalysis microscopic | 3399 |
| Urinalysis w/ reflex microscopic | 399 |
| Urine albumin/creatinine ratio, 24-hour | 634 |
| Urine albumin/creatinine ratio, random | 630 |
| Urine culture | 6564 |
| Urine cytology - reflex to FISH | 6301A |
| Urobilinogen, qualitative | 383 |
| Uroplakin III by IHC | 12376 - Technical only, 12379 - Technical & interpretation |
| Uroporphyrinogen decarboxylase, whole blood | 994 |
| UroRisk® diagnostic profile | |
| UroVysion by FISH (Bladder cancer) | 4280Z |
| Ustekinumab and anti-Ustekinumab antibody | 15272 |