In Connecticut, Counihan and his colleagues decided in January to delay about 30 percent of the Web portal functions they had hoped to have ready by October.

“We were beginning to slip in timing,” Counihan said. “We were getting these messages that we weren’t going to be able to hit our timelines because of the complexity. Some things were either requiring more time or coding than we had expected.”

When a consumer asks to be exempted from the individual mandate, for instance, the request will probably have to handled manually, by an exchange worker, rather than automatically, by a computer. Technology to track those points at which customers give up on the application process — turning away from the Web site rather than completing the application — will also wait until a later date.

“This is a two- to three-year implementation we’re doing in 10 months,” Counihan said. “I wish we had one more year.”