Tuesday is National Voter Registration Day, a nonpartisan moment to spread the word about why people should register to vote and how to do so. But for New York state voters, it’s also time to make sure your registration is set up for the kind of voting your want to do next year.

A person can register online here to vote in New York State. Paper forms still work, too (here’s the English version, and the Spanish).

Information about eligibility is here, but the basic requirements are that you be a U.S. citizen, 18 years or older, a resident of the state for at least 30 days before the election, not in prison or on parole for a felony conviction (unless there’s been a pardon or restoration of rights) and not “adjudged mentally incompetent by a court.” You also can only be registered in one state at a time. One can check on one’s voter registration status using this tool.

To participate in the general election this November 5—when voters will decide on charter-revision proposals as well as the public advocate race, among other contests—your registration form has to be postmarked by October 11 and received by your local board of elections by October 16. There are also deadlines in late October and early November for absentee ballots.

If you are a registered voter and your address has changed, you have until October 16 to get that fixed—and you do that by filing a new voter registration form.

The big wrinkle for registered voters concerns the 2020 elections. New York State will hold a presidential primary on April 28. That’s late in the primary season but given the large field on the Democratic side and the never-ending questions about President Trump’s ability to withstand a possible impeachment effort, it could still be an important day. In June of 2020, primaries will be held for state legislative offices (Assembly and State Senate) and Congress. Those results will shape the general election, where the outcome could affect the balance of power in Albany and Washington.

Right now, it is likely that 22 percent of voters in the city and 27 percent of voters in the state will not be able to participate in the those major-party primaries because New York State primaries are “closed,” meaning exclusively for members of the parties holding the primary. While the Green, Working Families, Conservative and Reform parties do hold primaries occasionally to determine who gets their ballot lines in November, their voters cannot vote in the Democratic or Republican primaries (or vice versa). One in five voters in New York State do not belong to any party.

That’s their right: There’s absolutely no obligation to enroll in any party, let alone a particular one. However, if you are already registered to vote and you want to change your party affiliation in New York State so you can take part in the 2020 primaries, you have to do so by this October 11. The deadline is ridiculously early, but at least the process is simple: Just register to vote again and designate the party you want to join.