As of April 22, 2010 a law came into effect that requires contractors to test for lead on any dwellings built prior to 1978 and take appropriate measures if lead is found. All contractors must be lead certified by the EPA as this does apply to replacement windows and doors.
Previously, owner-occupants of homes built before 1978 could certify that no child six years of age or younger or pregnant woman was living in the home and “opt-out” of having their contractors follow lead-safe work practices in their homes. On April 23, 2010, to better prevent against lead paint poisoning, EPA issued a final rule to apply lead-safe work practices (PDF) (18 pp, 121K) to most pre-1978 homes, effectively closing the exemption. The rule eliminating the opt-out provision became effective July 6, 2010.
Ultra Windows is lead certified to perform the testing and to handle any repairs in homes with lead.
You can read more about this on the EPA website.