Maria Contreras-Sweet, the new administrator of the United States Small Business Administration, emphasized the importance of the effort. “Health care remains a top concern for small-business owners across the country,” she said. People who work for small businesses are less likely to have insurance than people at large companies, and they typically pay more for the same or similar coverage.

Image Maria Contreras-Sweet, a federal small-business official. Credit... Kevin Lamarque/Reuters

The SHOP program promised affordable new insurance options, but it got off to a slow start, in part because officials were preoccupied with the individual marketplace. California signed up 1.4 million people through its individual exchange, but its small-business exchange enrolled only 1,700 companies, with 11,500 employees and dependents. In Minnesota, the small-business exchange signed up 190 employers covering 1,500 people.

The range of “employee choice” varies from state to state, even among states using the federal exchange. In some states, employers can select a level of coverage — bronze, silver, gold or platinum — and allow employees to choose any plan from any insurance company in that category. The different “metal levels” reflect the generosity of coverage: the percentage of costs paid, on average, by a health plan.

What employers cannot do in the federal exchange is offer employees a choice of levels.

“It would be really nice if we could offer plans from different metal levels,” said Joseph A. Cerino, the owner of an Ohio company that makes adhesive products. Federal officials said that would be difficult to administer and could destabilize insurance markets if large numbers of sicker people enrolled in certain plans.

Emily Black Bremer, president of the Missouri Association of Health Underwriters, said she had run into difficulty using a special portal for agents and brokers with small-business clients.

“I tried it for myself,” Ms. Bremer said. “I could not get in with my user name and password. There was an authentication issue with my login that caused a glitch.”

Nicholas A. Moriello, the president of Health Insurance Associates in Newark, Del., praised the Obama administration for soliciting the views of agents and brokers. He said he hoped the new website would work as well in practice as it did in a demonstration at the White House on Oct. 24.