Washington's health care exchange will likely be off line until Sunday morning.

The site was working for the first few hours of open enrollment Saturday, until a problem with tax credit calculations was discovered.

Officials at the exchange said Washington Healthplanfinder appeared to be working fine at first. When the exchange's automatic quality control system reported the problem, they decided to shut the whole system down at about 10:30 a.m. to fix it.

Exchange CEO Richard Onizuka says the tax credits were off by just a few dollars in some cases. But they do not want to give consumers inaccurate information so the site will be down until the problem is fixed.