With just a few weeks left before a deadline to get health coverage, lingering bugs lurk in the part of HealthCare.gov that you can't see. And since time is running out to get things right, health officials on Thursday urged insurance companies to cover some enrollees even if their premium checks haven't come in. Under the law's guidelines, consumers have to sign up for a health insurance exchange — and pay their first month's premium — by the end of December if they want coverage in January. "The short time period presents a number of challenges," says Robert Zirkelbach, a spokesman for America's Health Insurance Plans, an industry trade group.