HARRISBURG – Pennsylvanians who are not already registered to vote, but wish to participate in the May 19 primary election should be sure to register no later than Monday, May 4. To be eligible to vote in the primary, you must be a U.S. citizen for at least one month before the election; a resident of the election district in which you register to vote for at least 30 days before the election; and at least 18 years of age on or before the date of the primary. Under state law, only voters registered as Republicans or Democrats may vote for candidates in the primary election. Persons may register to vote by clicking on the banner below or you can visit your county voter registration office.  Voters who prefer to vote by mail-in or absentee ballot have until May 12 to apply for the ballot and until 8 p.m. on May 19 to return it.