Pennsylvania’s finally joining in on the 2016 presidential election — 281 delegates will be up for grabs in the primaries April 26.

Pennsylvania voters will be able to cast their ballots for president, Senate and Congress nominations for the Republican, Democratic and Independent parties. In preparation, voters must register by March 28, according to the Allegheny County Elections Division.

Pennsylvania runs a closed primary:

According to VotesPA, with a closed primary, voters in Pennsylvania must be registered as Republicans or Democrats in order to vote and may only vote within their registered party. People registered as Independents will only be allowed to vote on the proposed amendments to the Pennsylvania Constitution, which seek to change how the state disciplines its justices and judges.

Excluding potential dropouts, this year’s Republican presidential ballot consists of Donald Trump, Ted Cruz and John Kasich. The Democratic presidential ballot consists of Bernie Sanders and Hillary Clinton. Jill Stein, who ran for the presidency for the Green Party in 2012, is running on the Green Party’s presidential ballot, and Gary Johnson, a former governor of New Mexico, is running for the Libertarian Party.

Additionally, Democrats Janis Brooks and Mike Doyle are running for positions as U.S. representatives for Pennsylvania’s District 14, which includes Pittsburgh and surrounding neighborhoods.

Democrats John Fetterman, Katie McGinty, Joe Sestak and Joseph Vodvarka are running for U.S. Senate, along with Republicans Pat Toomey and Everett Stern.

The primary elections will determine each party’s nomination for representative and senator as well as president.

Voters can register or change parties online or through the mail:

Voters interested in registering, changing their names or addresses or changing their party affiliations can do so online at www.register.votesPA.com. Registering to vote requires a driver’s license or PennDOT ID card, social security card and, for those making changes to their registry, a voter registration number. The site also has print applications available, which voters must send into the county voter registration office by March 28.

Voters who are registered in a municipality other than Pittsburgh, but who want to vote here, must submit an absentee ballot application one week before the elections. The application for an absentee ballot, which can be found at PA.gov, must be received — postmarks do not count, according to the application — by the local county of board elections by 5 p.m. April 19.

Polling places are located in multiple Pitt buildings:

Residents of University buildings located in the quad — Amos Hall, Holland Hall, Brackenridge Hall, Litchfield Towers and McCormick Hall — can vote at the William Pitt Union. Those who live on upper campus and in Lothrop Hall can vote in Soldiers and Sailors Memorial Hall and Museum. Ruskin Hall residents can vote at St. Paul’s Synod Hall auditorium on North Dithridge Street. Bouquet Gardens residents can vote in the Posvar Hall lobby. All of these locations are wheelchair accessible.

Students who live in South Oakland, North Oakland, Shadyside or other neighborhoods within the city must check their polling location by entering their address with the municipality of Pittsburgh at Allegheny.pa.us.

Primary elections determine each party’s presidential nomination:

Pennsylvania has 210 Democratic delegates and 71 Republican delegates. Candidates win their party’s nomination when they secure a simple majority of delegate votes — the same applies for each state individually.

Candidates win delegates based on the number of primary votes they receive, so each vote in the primary helps the parties determine who wins the state, and thus who wins the party nomination.

Parties will announce their nominations at the Republican National Convention in Cleveland on July 18, and the Democratic National Convention in Philadelphia on July 25.