The Obama administration announced new rules under Obamacare on Monday that target nonprofit hospitals’ efforts to get paid by their patients.Nonprofit hospitals, which serve a charitable purpose and are often religiously affiliated, will now be subject to strict rules on when and how they can collect payments from customers, thanks to regulations included in the health-care law. As a condition of their tax-exempt status, these hospitals must “take an active role in improving the health of the communities they serve,†Treasury Department deputy assistant secretary for tax policy Emily McMahon wrote in a blog post Monday. Under the new IRS...