- Pancreatic Elastase, Fecal
- Pap Smear Test: Conventional
- Pap Test: ThinPrep®
- Pap Test: ThinPrep® with Reflex to Human Papillomavirus (HPV-HR) DNA Probe, High Risk
- Parathyroid Hormone (PTH), Intact
- Paroxysmal Nocturnal Hemoglobinuria (PNH) – CD55/59 Erythrocytes, FLAER Granulocytes/Monocytes
- Partial Thromboplastin Time
- Pediatric Islet Autoantibody Panel (ICA, GADA, IA-2A, IAA and ZnT8A)
- Pediatric Pathology
- pH
- Pharmocogenomics APOL1
- Pharmocogenomics CYP2C19
- Pharmocogenomics NAT2
- Pharmocogenomics TPMT
- Pharmocogenomics TPMT and NUDT15
- Pharmocogenomics YEATS4
- Phencyclidine (PCP)
- Phenylalanine and Tyrosine
- Phosphorus, Inorganic
- Phosphorus, Inorganic – Random Urine
- Platelet Count
- Podiatric Pathology
- Potassium, Blood
- Potassium, Random Urine
- Prealbumin
- Prolactin
- Prostate-Specific Antigen (PSA), Free
- Prostate-Specific Antigen (PSA), Total
- Prostate-Specific Antigen (PSA), Total and Free
- Protein Electrophoresis
- Protein, Random Urine
- Prothrombin (Factor II) G20210A Mutation Analysis
- Prothrombin Time with International Normalized Ratio (INR)
- Pulmonary Pathology