Protecting Taxpayer Confidentiality Through Safeguards Act This bill amends the Internal Revenue Code to prohibit the disclosure of tax returns or return information to a contractor or other agent of a federal, state, or local agency unless the agency requires the contractor or agent to provide certain safeguards to protect the confidentiality of the returns or return information. The bill also requires the agency to conduct on-site reviews to determine compliance with requirements and meet certain reporting and certification requirements.