Help Please log in to determine if you are eligible to purchase PT Programs. KIDNEY STONE ASSESSMENT - KSA Analytes/procedures in bold type are regulated for proficiency testing by the Centers for Medicare & Medicaid Services (CMS). Analyte Challenges per Shipment Number of Shipments Citrate 3 Two shipments per year Cystine 3 Oxalate 3 Sulfate 3 Program Information Three 13.5‑mL liquid urine specimens Shipping Schedule Shipment A: May 26 Shipment B: November 23 Guest Log in/Register Customers Who Bought This Item Also Bought Atlas of Fundamental Infectious Diseases Histopathology VIEW DETAILS >