The online system was supposed to go live Tuesday, when individuals and small businesses are to be able to begin shopping for 2014 health plans on new marketplaces created by the Affordable Care Act.
Individuals who don't get health coverage through their employers will still be able to enroll online through the www.healthcare.gov site or through state websites in those states that are running their own insurance marketplaces, according to an administration official.
But the online enrollment system for small businesses in 35 states with federally run marketplaces, such as Illinois, will not be operational until November, the administration official said.
Small businesses in most of the 15 states that are running their own small-business marketplaces, including California, are expected to be able to begin online shopping next week.
The law allows businesses with fewer than 50 employees to use the marketplaces to shop for health plans that must meet new minimum standards for coverage.
The delay, first reported by the Economic Policy Journal, is the latest in a series of setbacks for the Obama administration, which has been scrambling to launch the marketplaces, a central feature of the law the president signed in 2010.
This summer, the administration announced it would delay for a year penalties on large employers that do not provide benefits to their workers.
An administration official, who was not authorized to speak on the record, said small-business owners should still have enough time to shop for health plans before coverage is set to start in January.
Starting Tuesday, the SHOP Small Employer Call Center will operate an expanded schedule to assist employers Monday through Friday, 9 a.m. to 7 p.m. Eastern time at 800-706-7893, according to the administration.