The administration is confusing and frustrating businesses and lawmakers with new Obamacare regulations that define full-time as working just 30 hours, but sometimes rely on the traditional 40-hour week and even a new and unheard of standard of 35 hours in guidance to employers facing a maze of requirements.

Congressional officials and business leaders, for example, cited to Secrets IRS guidance issued in February. That 227-page package, they said, appears to set two standards: 30 hours for hourly workers, and 40 hours for salaried workers even though the law requires employers to offer healthcare to those who work 30 hours or more, or pay a fine.