Ms. Fowler is not a registered lobbyist, but she does provide in-house advice on the bill — work that has drawn criticism from publications like the British newspaper The Guardian and the Web sites Salon and The Huffington Post, where the journalist Bill Moyers singled out Ms. Fowler, asserting that “when push comes to shove, corporate interests will have the upper hand.”

Yet the progression from government to the private sector is also predictable, a window into the peculiar rhythms of life in the capital. Young aides, often fresh out of college or graduate school, acquire highly specialized knowledge but eventually settle down, build lives and long for jobs that pay more and let them see their children at night.

Those were considerations for Dr. Hughes, who has a 3-year-old, and Yvette Fontenot, a mother of three who began her Washington career in 1997, analyzing Medicare for the Office of Management and Budget. Ms. Fontenot worked on the health bill as a Finance Committee aide and later moved to the White House. Four months ago she joined Avenue Solutions, a boutique lobbying shop.

“Every client out there is interested in the Affordable Care Act and what it means,” said Ms. Fontenot, who like Dr. Hughes concentrates on strategic advice. With exchanges soon to go live, she said, companies “want to know whether there is a potential to build on this, to make changes.”

Many of the former health care officials are lawyers or lobbyists, though not all. Nancy-Ann DeParle, Mr. Obama’s former “health czar” and later his deputy chief of staff, now guides health care investments as a partner in a new private equity firm, Consonance Capital, with colleagues from her pre-White House days. Bob Kocher, a doctor, management consultant and former member of Mr. Obama’s economics team, is a California venture capitalist, helping finance health start-ups.

“The tentacles of Obamacare touch everybody — health insurance companies, doctors, the payers,” said Ivan Adler, an executive recruiter with the McCormick Group who specializes in K Street, Washington’s lobbying corridor. “This law is so complicated that you really have to have somebody playing sherpa in order to follow it, because it is fluid and changing. And the supply of people who understand it is way smaller than the demand.”

Since 2011, Mr. Adler said, he has counseled dozens of job-hunting former officials with health care experience, including some lawmakers.