America's pharmacy benefit managers administer prescription drug plans for more than 210 million Americans with health coverage provided through Fortune 500 employers, health insurance plans, labor unions, and Medicare Part D. PBMs emerged in the 1980s, primarily to provide cost-effective drug distribution and claims processing for the healthcare industry. The PBM industry further evolved in response to the significant escalation of healthcare costs in the 1990s, as sponsors of benefit plans sought to more aggressively contain their costs. PBMs developed strategies to effectively influence both supply and demand. Through purchase discounts, retail pharmacy networks, mail pharmacy services, preferred drug list administration, claims processing and drug utilization review, PBM companies created an opportunity for health benefit plan sponsors to deliver prescription drugs in a more cost-effective manner while improving compliance with recommended guidelines for safe and effective drug use. Knowledge Source's 2008 Pharmacy Benefit Management Market Overview, 250 pages in length, provides insight into the trends and issues affecting the pharmacy benefit management market. Knowledge Source's Pharmacy Benefit Management Market Overview also identifies 75 of the leading market participants and provides a brief profile on each company, which includes (when available): company background, company strategy, products and services, financial statistical information, and recent activities.