Over the past decade, Express Scripts has become the largest pharmacy benefit manager in the U.S. as the industry has consolidated. The company processes more than 1.5 billion claims every year. The question now is if it can compete using its unique stand-alone business model with rivals like CVS Health that pursue a multi-pronged approach. Express Scripts has benefited from the wave of newly insured patients as a result of the Affordable Care Act and has significantly expanded its profit margins over the past six years. The company’s simmering contract dispute with insurance giant Anthem, its largest customer and 18% of its revenue, was an undercurrent to 2016; the companies severed ties in April 2017, sending Express Scripts’ stock plummeting. The move leaves the company to find a way forward as it still covers 65 million people and processes about 1 billion prescriptions a year.