Advances in claims paying technology (e.g., the ability to capture and electronically transmit claims) and the increased desire of payers to affect savings at any cost, have resulted in increased use of techniques that threaten the viability of PPO networks as an effective cost containment tool.  The term “provider discount abuse” has been coined to refer to practices intended to take advantage of providers in the managed care environment.  While there is legitimate disagreement as to the validity of some of these tactics, little exists as to the impropriety of “silent PPOs” and “PPO network stacking.”