The government might have known that the HealthCare.gov rollout would be a mess if it had properly vetted the contractors that built the online health-insurance exchange. (Andrew Harrer/Bloomberg)

The federal agency responsible for developing HealthCare.gov did not properly vet the contractors it hired to build the Web site and failed in many other aspects of planning it, according to a government review.

In a report Thursday, the Department of Health and Human Services’ inspector general said that the Centers for Medicare and Medicaid Services “did not perform thorough reviews of contractor past performance when awarding two key contracts,” among other issues.

The findings confirm problems that The Washington Post first highlighted in a pair of articles more than a year ago. One of the reports showed that CGI Federal, a key contractor in the development of the site, had ties to failed projects, while an earlier story revealed that the company was filled with executives from a troubled IT firm.

HealthCare.gov contract: Politics not a factor, but neither were firm’s ties to failed projects

Health-care Web site’s lead contractor employs executives from troubled IT company

The government spent about $800 million to build HealthCare.gov, which was plagued with problems and barely functioned during its botched launch in October 2013. CMS eventually fixed the glitches, but the remedies added millions to the cost of the project.

Among the many ways CMS failed to follow contracting requirements and best practices, the inspector general said, the agency did not appoint anyone to coordinate the efforts of the 33 contractors who helped develop the Web site. Additionally, the agency made decisions that limited the number of bids and put the government on the hook for cost increases.

CMS and its parent agency, the Department of Health and Human Services, agreed to all of the inspector general’s recommendations, which included calls for HHS to revise its acquisition guidance to ensure that contractors are adequately vetted and assess whether CMS should assign someone to coordinate complex IT projects in the future.