HealthCare Access will partner with other groups to visit festivals and community organizations and canvass neighborhoods. It will also staff a hot line to answer questions. Details of the outreach efforts, which are to begin this summer, are still being worked out.

"We want to blanket these three counties," Westcoat said. "We will deploy people to a wide variety of places."

The state's outreach will include efforts to find hard-to-reach populations, with the use of bilingual materials for immigrant communities.

A consultant who works with small businesses said convincing people about the benefits of the Obama health care initiative will be a tough job. Michael Merson, former chairman of CareFirst BlueCross BlueShield, the state's largest insurer, said many small businesses are confused by the mixed messages they are getting, with many considering opting out or hiring more part-time workers to avoid providing coverage.

Leaders of the national outreach campaign acknowledge that the effort won't be easy.

"We know it's a big task," said Anne Filipic, president of Enroll America, the nonprofit formed to lead the effort. She said most of the nation's uninsured — 78 percent, according to the organization's most recent survey — "don't know about this new opportunity."

Filipic, a former White House official who worked on Obama's 2012 campaign, said the nonprofit plans to hire about 200 people and engage thousands of volunteers in coming months to focus on community activities.

Enroll America is also working with hospitals, health clinics and physician groups to train medical professionals to educate patients about enrolling in health insurance. For example, Doctors for America, a nonprofit that pressed Congress to pass the health care law, is training 100 doctors and medical students, according to Dr. Alice Chen, the group's executive director.

Filipic said Enroll America will start a paid media campaign later this year.

Filipic would not say how much the group plans to spend on the outreach effort or what many of its corporate partners will do to assist. An official with Enroll America said the budget would be "in the tens of millions" of dollars.

Noam N. Levey of Tribune Newspapers contributed to this article.