The Affordable Care Act (ACA), also known as Obamacare—created to extend health coverage to millions of uninsured Americans—was signed into law in March 2010. The act expanded Medicaid eligibility, started the Health Insurance Marketplace, prevented insurance companies from denying coverage due to preexisting conditions, and required plans to cover a list of essential health benefits. Lower-income families qualify for subsidies for coverage purchased through the Marketplace.