As 501(c)(3) organizations, PTAs must follow special rules regarding ballot measures and candidates for public office.
In brief, PTAs may advocate for or against ballot measures such as initiatives and referenda, but their spending is subject to IRS lobbying limits. For more specific information, check here (en español).
On the other hand, PTAs may NOT endorse candidates for public office, contribute to their campaigns, rate them according to their votes on key issues, or allow unequal access to PTA facilities or events. PTA officers may endorse candidates and contribute to their campaigns, but must do so as individuals and may not use their PTA titles. In fact, if well known as such within a community, it is best for PTA officers to avoid partisan endorsements to avoid giving the impression of an organizational endorsement. For more specific information, check here (en español).
PTAs may provide a tremendous public service, however, by holding a candidate forum to which ALL candidates for a public office are invited. For a handy step-by-step guide, check here.
Finally, here is a comprehensive guide to keeping your PTA on track during an election year.