Current recommended procedure for pretransfusion testing, as previously described, is to obtain the ABO and Rh type of the recipient RBCs and perform an antibody screen on the serum of the recipient. This has become known as type and screen. This is followed by a crossmatch on blood units actually transfused; only the immediate spin procedure is mandated by AABB rules, but testing can be more extensive. Except in certain emergencies, physicians who anticipate need for blood order an estimated amount (number of units) to be processed in case they are needed. For many years, all of these units were typed and crossmatched immediately. Some institutions now maintain a “maximum surgical blood order schedule” in which the average blood need for various surgical procedures is calculated and crossmatch is performed routinely only on these units, with others subjected only to type and screen unless actually needed. In other institutions, only type and screen is done routinely, but when the order to actually transfuse is given, a crossmatch is performed. In either case, since many blood units are ordered that are never transfused, type and screen decreases the number of crossmatches required. Some blood bankers maintain that even the immediate spin can be eliminated with acceptable safety, thereby transfusing without any crossmatch.