Effective January 4, 2014:
The Reduction of Lead in Drinking Water Act was signed into law in 2011 and took effect on January 4, 2014.
Accordiing to the EPA's "How to Inentify Lead-Free Certifications Marks for Drinking Water Systems and Plumbing Materials". Starting January 4, 2014 there are prohibitions the use of lead in all pipe, pipe fittings, plumbing fittings and fixtures.
The following is a link to download the EPA document listed above