In a letter of resignation obtained by LifeHealthpro, Larsen wrote that "After more than two years at HHS I have made the difficult decision to leave my role at CCIIO and return to the private sector. It has been an extraordinary experience to work here at this moment and it has been a particular privilege to do so with all of you. I am proud of all that we have done together to implement the Affordable Care Act and help millions of Americans get access to better and more affordable health care."

"I have been fortunate from my first day on the job to be part of this historic effort and to do so with all of you has been all the more rewarding. We have great leaders in Secretary Sebelius, Bill Corr, Marilyn Tavenner, Mike Hash and so many others across the entire CMS and HHS team and I leave knowing you are in good hands to accomplish all that is ahead…," Larsen wrote June 15.

The PPACA Act of 2010 requires state and federal agencies to set up the exchanges by 2014. The exchanges are supposed to help individuals and small employers use new tax credit programs created by PPACA to buy health coverage.

In a letter to staff today, Tavenner wrote about Larsen and his work: "Together we have leveraged CMS' strengths as we took on these new responsibilities and I am proud of our efforts to hold insurance companies accountable to consumers and our work with states and others to build a new insurance marketplace. His efforts helped to lay the foundation for our continued success and have put us on a path to make sure that these new marketplaces are available to consumers in every state in 2014."

Less than a year ago Joel Ario, then director of the Office of Insurance Exchanges at CMS decided to leave his post, after about a year on the job.

Both Ario and Larsen have been state insurance regulators in previous lives, Larsen in Maryland and Ario in Pennsylvania and Oregon.

Larsen then began working with Ario's deputy, Tim Hill, to manage the exchange development effort, according to a copy of an internal memo sent by Larsen to CCIIO employees at the time. 

One health care lobbyist, not a fan of PPACA, asked  if folk were jumping a "sinking ship in advance of a Supreme Court decision?" 

A Washington healthcare analyst, who asked not to be quoted by name, said this decision does not imply that the Supreme Court has given a heads-up to the White House that the Patient Protection and Affordable Care Act will be declared unconstitutional. "The Supreme Court does not work that way," she said.

It was not immediately known where Larsen will be going next.

Although he noted a return to private sector, much of his work has been with the state and federal government. He has worked for Amerigroup Corp., a public managed care company and as a law partner.

At HHS, Larsen served as the Director of the Division of Insurance Oversight for nine months prior to becoming the Deputy Administrator and Director of the new CCIIO. Prior to joining the CCIIO, Larsen served in a number of capacities at Amerigroup, a public managed care company serving the Medicaid and Medicare populations. 

Larsen also served six years as Maryland Insurance Commissioner, Chief Legislative Officer for Governor Parris Glendening, and Chairman of the Maryland Public Service Commission for Governor Martin O'Malley, and was a partner at the law firm Saul Ewing, LLP.

At the state regulatory level, various interest groups are commenting on a draft of a form review white paper now being developed by a team at the Exchanges Subgroup at the National Association of Insurance Commissioners (NAIC), racing against the clock for review, adoption and state implementation.