Harris requested a federal audit of the Maryland Health Benefit Exchange last spring, saying more than $100 million in federal funds used to build the Obamacare marketplace had resulted in an exchange that flopped during the first year of open enrollment in Affordable Care Act plans.
"Maryland officials ignored early warning signs and chose to waste and abuse federal taxpayer money by opening up what they knew was a flawed exchange to the public," the congressman said in a statement in March.
"I have confidence that the nonpartisan and independent HHS inspector general will thoroughly investigate and bring to light how hundreds of millions of dollars were wasted on one of the worst exchange rollouts in the country."
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Maryland's exchange finished 44th in the nation in signing up potential Obamacare enrollees. It enrolled just 67,757 people in private insurance plans, or 16.2 percent of the estimated pool.
On the heels of its launch, as the exchange tried to get its website working properly, the exchange's director, Rebecca Pearce, took a weeklong vacation in the Cayman Islands in late November. She resigned in December, after her ill-timed trip was disclosed.
The exchange's performance even after Pearce left remained bad enough that officials decided to scrap the exchange's tech platform altogether. Maryland's exchange is now moving to use the software code from Connecticut's state-run Obamacare marketplace, whose performance enrolling people in insurance plans was widely lauded, and greatly exceeded original estimates.
On Tuesday, Kevin Counihan, the head of Connecticut's exchange, Access Health CT, was named as the first-ever CEO of HealthCare.gov, the federal Obamacare marketplace that sells insurance in 36 states that are not running their own exchanges.
—By CNBC's Dan Mangan