HealthCare.gov is a health insurance exchange website operated under the United States federal government under the provisions of the Patient Protection and Affordable Care Act (ACA, often known as 'Obamacare'), designed to serve the residents of the thirty-six U.S. states that opted not to create their own state exchanges. The exchange facilitates the sale of private health insurance plans to residents of the United States and offers subsidies to those who earn less than four times the federal poverty line. The website also assists those persons who are eligible to sign up for Medicaid, and has a separate marketplace for small businesses.The October 1, 2013 roll-out of HealthCare.gov went through as planned, despite the concurrent partial government shutdown. However, the launch was marred by serious technological problems, making it difficult for the public to sign up for health insurance. The deadline to sign up for coverage that would begin January 2014 was December 23, 2013, by which time the problems had largely been fixed. The open enrollment period for 2016 coverage runs from October 1, 2015 to January 31, 2016. State exchanges also have had the same deadlines; their performance has been varied.The design of the website was overseen by the Centers for Medicare and Medicaid Services and built by a number of federal contractors, most prominently CGI Group of Canada. The original budget for CGI was $93.7 million, however this grew to $292 million prior to launch of the website. While estimates that the overall cost for building the website had reached over $500 million prior to launch, the Office of Inspector General released a report finding that the total cost of the HealthCare.gov website had reached $1.7 billion. On July 30, 2014, the Government Accountability Office released a non-partisan study that concluded the administration did not provide ""effective planning or oversight practices"" in developing the HealthCare.gov website.