Most Pennsylvania voters this election will cast their ballots at the polls on election day. But for those who can’t make it in person on May 21, absentee voting is available.

Be aware: Voting absentee is a multi-step process that can take several days or longer. If you’re planning on voting absentee, don’t delay, or your vote might go uncounted. Pennsylvania voters have until 5 p.m. Tuesday, May 14, to request a ballot, and the completed ballot must be received by county elections officials by 5 p.m. Friday, May 17, or it won’t be counted.

Here’s what you need to know.

Who can vote absentee?

In Pennsylvania, you need to have a reason for voting absentee, including physical disability or illness.

The most common one is being away from home on election day — though that applies only to voters who will be away from the municipality in which they live. If you live in Philly and will work on election day all day in the city, you’re not eligible for an absentee ballot.

How to vote absentee

First, voters must apply. The application is a paper form that, even if you fill it out online, must be mailed or hand-delivered to county elections officials. Find the form here in multiple languages.

To be accepted, that application must arrive by 5 p.m. Tuesday.

Once an application is approved, county elections officials send a paper ballot in the mail. Fill out the ballot, place it in the envelope, sign the envelope, and then mail it or hand-deliver it. Any ballots arriving after 5 p.m. May 17 will be rejected.

Why you shouldn’t wait

In Pennsylvania, the absentee ballot deadlines are strict and the timelines are tight. What matters is when a ballot is received by elections officials, not when it is mailed. And mail delivery can be unpredictable.

The deadlines may change in the future — lawmakers have proposed changing the deadlines and civil rights groups are suing the state — but for now, the timeline is tight.

Plan on voting absentee? Don’t wait.