In the wake of Obamacare’s troubled rollout, many have drawn comparisons between its underwhelming unveiling and the 2005 rollout of Medicare Part D. The launch of Medicare Part D was rocky: The introduction of the online ”Prescription Drug Plan Finder,” which allows seniors to browse through their coverage options, was delayed several times; later, 231,000 Medicare beneficiaries mistakenly received a refund for premiums they had paid for prescription drug coverage that, in total, cost the federal government $50 million. Iowa senator Chuck Grassley, one of the authors of the legislation that created the prescription-drug benefit, called Part D “the federal program equivalent of a Mars landing.”

Mark McClellan, then the administrator of the Centers for Medicare and Medicaid Services, oversaw the rollout of Part D. “The issues took a few weeks to work through but we had millions of people using the website from the start, from the time it went up,” he tells National Review Online. McClellan says the biggest challenge was getting “very specific, detailed information” on drug pricing that was then personalized for seniors. “Something like that hadn’t really been attempted before,” he tells me.

Some have questioned whether the government is capable of administering a program like the Affordable Care Act. Like Plan D, it is a large federal program involving CMS and the federal government, and in terms of sheer volume McClellan notes that the online infrastructure created to support Part D had to accommodate vastly more consumers than Healthcare.gov: 45 million seniors were enrolled in Medicare overall and a majority of them received coverage through Medicare Part D, whereas the White House hopes to enroll 7 million Americans in health-care plans in the first year — that’s just a fraction of the total uninsured population. But the ACA, he points out, is more complex in that it will be administered by both the federal government and the states, and because it must cater to a more diverse population.

Of the problems currently facing Healthcare.gov, now being addressed by a “tech surge” that is drawing on private-sector expertise, McClellan says they will not impact the ACA’s success over the long-term so long as they’re temporary. “It becomes a bigger issue if people are still unable to enroll in mid November, because people want to enroll in plans by January 1.” The website doesn’t need to be working perfectly, he says, but people need to have alternatives – like a working hotline to call. Nonetheless, the former CMS chief would have recommended the administration push back the launch date rather than go live on October 1: ”The advice that I was giving well before the start date was that you don’t have to do everything in October, it may be best to delay it until November,” he offers.

I ask McClellan about CMS’s last-minute decision to prevent consumers from shopping for plans without first creating an account, which has been the subject of criticism. In testimony before a House panel yesterday, federal contractors who helped build Healthcare.gov pointed to this change as one of the major contributors to the problems that have plagued the site. McClellan mentions that his staff conducted several focus groups when rolling out Part D, and the overwhelming preference among consumers was to be able to view costs in a transparent manner. “The pretty clear view and not just among seniors but a lot of the groups that we talk to was that it was important to have clear and transparent information about costs,” McClellan says, “That was from early on and we stuck with it.”