No, under the EPA RRP Rules for Lead-Safe Work Practices a Lead Certified Firm can either test for lead on the components where they may be disturbing lead-based paint or may presume the paint contains lead if the building was built before 1978.

That may or may not be a good idea. Because nearly 90% of buildings built before 1940 contain lead, presuming may work fine, but the vast majority of the buildings built in the 1970s DO NOT have lead paint. By testing, you determine exactly what surfaces do and do not have lead. If there is no lead, you simply document your test results and complete your project just like you would normally. This can dramatically limit your liability.