The online marketplace for health-care insurance will open its call center Sunday to assist last-minute consumers trying to buy insurance before Monday’s deadline to sign up in time to receive coverage as of Jan. 1.

DC Health Link’s call center will be open Sunday between 8 a.m. and midnight, said Mila Kofman, executive director of the D.C. Health Benefit Exchange Authority, the quasi-governmental entity that operates the online marketplace set up as part of the Affordable Care Act.

Kofman said Friday that DC Health Link officials were still reviewing the impact of the Obama administration’s decision Thursday to relax the new rules for millions of consumers whose individual insurance policies have been canceled, saying they can buy catastrophic policies or avoid a requirement that most Americans have health coverage. Such catastrophic plans are available on DC Health Link for people who cannot afford other coverage, Kofman said.

The Web site is; the call center number is 855-532-5465.