How to Vote in Colorado’s Presidential Primary

  • Colorado voters hold letters spelling out "Colorado Votes"

This year, Colorado will hold our presidential primary elections on March 3rd, also known as “Super Tuesday.” Every eligible voter who will be 18 years old in time for the general election on Tuesday, November 3rd is entitled to vote in a primary. Ballots were mailed out to registered Colorado voters starting on February 10th, and your ballot must be returned by March 3rd in order to make your voice heard!

Wait, what happened to the caucus?

In 2016, voters passed ballot measures to adopt an open primary voting system instead of a closed caucus system to select presidential candidates for the party nominations. This means that Colorado voters will no longer caucus for their preferred presidential candidate, and instead will vote for their preference in a primary that unaffiliated voters will also be able to vote in.

How do I cast my ballot for the presidential primary?

The primary election will work just like any other election in Colorado: registered voters will get mailed a ballot and you must cast your vote by election day, March 3. You can return your ballot by mail OR drop it at any dropbox. To find a dropbox near you, visit*. After Monday, February 24th, it’s too late to mail back your ballot. Ballots must be received by 7 PM on Tuesday, March 3rd.


Person dropping ballot into box.

Voting is one of the most important things you can do to protect our environment and what you love about our state.


I am registered unaffiliated, can I vote in the presidential primary?

Yes! Unless you previously requested only one party’s ballot, if you are registered unaffiliated then you will get mailed two ballots: one for the Republican primary and one for the Democratic primary. You can ONLY fill out and return one. If you mark and return both ballots, they will both be rejected and your vote will not count. So make sure to follow the instructions when you receive your ballot(s)!

I’m not registered or not sure if I’m registered to vote. What should I do?

You can update and verify your registration or register to vote for the first time up through and including election day by visiting or by visiting a Voter Service and Polling Center (VSPC) in your county. Voter Services and Polling Centers will be open starting February 24th until 7PM on Tuesday, March 3rd. To find the VSPC in your area and see the eligibility requirements, you can visit*.

I moved recently, what should I do?

You can update your voting address right now by visiting or in person at a VSPC when they open.

Are there other primaries on this ballot? 

Nope, this ballot is just for the presidential primary. There will still be the caucus and state assembly process starting on March 7th, where candidates for U.S. Senate and House, state legislative races, and other down-ballot offices work to qualify for the ballot for their party’s primary. Then, on June 30, voters will select the party nominees for these offices in the state primary.

Here’s a short hand of the important dates to remember:

  • Presidential primary: March 3rd.
  • State caucuses and assembly: Starting March 7th. This is one path for candidates to qualify for the state primary ballot for their respective party.
  • State primary: June 30th. Voters will select the party nominees for US Senate and House, state legislature, and other state-level offices.
  • General election: November 3rd.

*Just Vote! Colorado Election Protection is a non-partisan voter assistance project and is not affiliated with or promoting any party, candidate or ballot issue. Just Vote! Colorado is not affiliated with or responsible for the content of this piece.