California mail-in ballots increasingly rejected as late, study finds

By Darrielle Fair

California is seeing an increase in mail-in ballots arriving too late to be counted, raising concerns about how recent changes to U.S. Postal Service operations could affect voters ahead of the November election.

A recent study from the Public Policy Institute of California found that 1.1% of all mail ballots returned to election officials in the June 2026 statewide primary arrived late, an increase from 0.7% during the 2025 Proposition 50 special election and 0.3% in 2024.

The study found the increase was concentrated in areas where the Postal Service eliminated evening mail pickups. Researchers said the changes may be putting more ballots at risk of arriving after California’s deadline.

California allows counties to count vote-by-mail ballots that are postmarked on or before Election Day as long as they arrive within seven days after the election. For the Nov. 3 general election, ballots mailed back to election officials must be postmarked by Election Day and received by Nov. 10.

For Sacramento County, election officials say roughly half of voters have historically waited until Election Day to cast their ballots.

“It’s been pretty consistent in terms of the voter turnout on Election Day. We set it around 50% of our voters waiting until Election Day to vote,” said Ken Casparis, a spokesperson for Sacramento County.

The PPIC study examined changes to USPS operations, including the elimination of some evening mail pickups. Researchers found that ballots deposited after an earlier collection could remain at a local post office overnight before being transferred for processing, potentially affecting the date they receive a postmark.

The study found that the increase in late ballots was not limited to California. Washington and Oregon also saw increases in ballots rejected for arriving late, according to the research.

Mindy Romero with the PPIC said voters should consider how they plan to return their ballots before Election Day.

“When they’re casting their ballot, they need to make a plan, right? What method of getting their ballot in do they want to use?” Romero said. “And if they are using a vote-by-mail ballot, and if they are deciding to use the mail, making sure that they’re getting it at a time that it’s going to be processed through the USPS.”

Sacramento County pushes early voting

Sacramento County elections officials say they have received funding for voter outreach ahead of November, with an emphasis on encouraging people to return their ballots early.

“We do plan on encouraging folks to use our ballot drop boxes, especially as we get closer to the election, just so that they don’t run into any issues with postmark dates or delayed delivery to our elections office,” Casparis said.

Sacramento County plans to have more than 60 ballot drop boxes available throughout the community ahead of the election, according to Casparis.

California voters can return completed mail ballots to an official drop box, polling place, vote center or county elections office by 8 p.m. on Election Day. The Secretary of State recommends voters who choose to mail their ballots do so at least seven days before Election Day.

The state will begin opening secure ballot drop boxes on Oct. 6, while county elections officials will begin mailing ballots by Oct. 5.

“We’re hoping that there’s not too much disruption to our process and that voters still turn out the way that they normally would,” Casparis said. “We will be doing a lot of work with our media partners to get information out to the public about the correct ways to vote.”

What voters should know

The PPIC study found that rural areas have been particularly affected by the increase in late ballots, although postal delays are not the only reason a vote-by-mail ballot can be rejected.

Once a ballot reaches the county elections office, Sacramento County officials say it is reviewed by at least two elections staff members.

Voters should also monitor their mail, email or phone after returning a ballot in case the county contacts them about an issue that can be corrected.

California’s Secretary of State offers ballot tracking through its “Where’s My Ballot?” service, which allows voters to receive updates about the status of their returned ballot.