MINNEAPOLIS — Consumers won’t be able to use Minnesota’s new online marketplace for health insurance as planned this morning and will have to wait until sometime in the afternoon, the head of the state-run exchange said Monday.

April Todd-Malmlov, executive director of MNsure, said officials want to make sure the system connects properly with federal computer systems and that it’s secure before it goes live for consumers. MNsure officials had been saying for months they expected consumers could start signing up at the start of the business day today. She said they weren’t sure what time in the afternoon the system would be ready.

Enrollment begins today nationwide for coverage under the Obama administration’s Affordable Care Act. Roughly 300,000 uninsured Minnesotans are expected to buy insurance via the portal. The delay is one of several glitches in MNsure’s rollout that Todd-Malmlov spoke about late Monday afternoon.

“Generally, anytime you go into a new enterprise there are things you expect and things you deal with that are a bit unanticipated,” Todd-Malmlov said. “So we have always been planning to be up on Oct. 1. We do need to do that in coordination with our federal partners, and we want to make sure that we are doing that in a planned and not-rushed way to make sure that everything is ready to go and working on Day 1.”

The other problems include a list of approved outside “assisters” and “brokers” who can help people sign up that won’t be complete and posted until Wednesday. She said the last phase of their required training course didn’t become available until last week, and many still need to pass their background checks, so the helpers won’t be able to start working with consumers until they’re cleared.

Also, she said American Indians, many of whom qualify for special subsidies under the law, should wait a week before signing up because that part of the system isn’t working properly.

MNsure has been under scrutiny as its launch approached, coming under fire for a data security lapse as well as criticism for failing to include groups that work with minority communities in its initial plan for distributing federal grants to organizations that will aid in finding and enrolling the uninsured. On the positive side, MNsure boasts the lowest average premiums nationwide on three types of health plans offered under the overhaul.

Exchange officials aren’t expecting problems should the federal government be partially shut down, but Todd-Malmlov couldn’t promise they won’t hear differently Tuesday from the Department of Health and Human Services.

Consumers who visit the MNsure website Tuesday morning will see a message telling them to try back later, she said. MNsure’s call center will be open for answering questions but operators won’t be able to enroll people until the system launches.

Once that happens, residents will be able to shop for insurance plans, open accounts, determine if they’re eligible for financial assistance and sign up for coverage that will take effect Jan. 1. While consumers are required to have health insurance policies by then or pay penalties, Todd-Malmlov noted that open enrollment for the first year’s coverage will run through March 31.

Todd-Malmlov said MNsure expects “a lot of interest in the site” Tuesday, but “we don’t anticipate there will be a lot of enrollment in the first two weeks.”