A dozen or more companies likely participated in the enrollment site's construction and design.
Though federal health officials have not released a complete list, it is known that longtime contractor CGI Federal and a small Washington, D.C., firm called Development Seed were responsible for back- and front-end of healthcare.gov, respectively.
But a wider look at companies involved in the law's rollout reveals a who's who of D.C. contracting powerhouses, many of which are also political donors.
The Sunlight Foundation counted 48 organizations awarded contracts under the Affordable Care Act in a review of USASpending.gov and FedBizOpps.gov.
Among them are long-established players like Northrop Grumman, General Dynamics, Booz Allen Hamilton and IBM.
Seventeen of the Affordable Care Act contractors reported spending more than $128 million on lobbying in 2011 and 2012, while nearly 30 made substantial donations to federal candidates and parties, Sunlight reported.
The largest implementation contracts went to British contractor Serco ($114.3 million), CGI Federal ($93.7 million) and Quality Software Services, a subsidiary of United Health Group ($68.3 million).