Little is known about the health status of the 7.3 million Americans who enrolled in insurance plans through the Marketplaces established by the Affordable Care Act in 2014. Medication use may provide an early indicator of the health needs and access to care among Marketplace enrollees. We used data from January–September 2014 on more than one million Marketplace enrollees from Express Scripts, the largest pharmacy benefit management company in the United States. We compared the characteristics and medication use between early and late Marketplace enrollees and between all Marketplace enrollees and enrollees with employer-sponsored insurance. Among Marketplace enrollees, we found that those who enrolled earlier (October 2013–February 2014) were older and used more medication than later enrollees. Marketplace enrollees, as a whole, had lower average drug spending