Maryland’s primary election results are expected to be delayed.

There are competitive primary contests for governor and some House seats on the ballot Tuesday in Maryland. Just don’t get your hopes up about knowing the results right away … or perhaps even soon.

The public “might not know results for days,” warned the local news site DCist. “Be patient,” advised William G. Voelp, chairman of the State Board of Elections, in The Washington Post.

Exactly how much patience will be needed is unclear.

The pandemic has fueled a sharp rise in the number of people voting by mail. State officials throughout the country have rushed to update their rules to handle this change. But in Maryland, election officials are prohibited from processing, let alone counting, thousands of ballots that have already been sent in by mail until “after the election,” according to the National Conference of State Legislatures.

No other state currently has such a prohibition, according to the group. Many states permit the processing of ballots either “upon receipt” or at another point before Election Day. Some wait to begin the processing until Election Day, like Pennsylvania (starting at 7 a.m. ), South Carolina ( 9 a.m.), South Dakota (“prior to the close of the polls”) and Wisconsin (“after the polls open”).

Donna J. Duncan, an assistant deputy for constituent relations with Maryland’s Board of Elections, said in an interview that absentee and mail-in ballots will begin to be counted on the 21st.

“Most local boards will finish counting on the 29th but some of the larger jurisdictions will go into the first week of August, at least,” Ms. Duncan said.

Back in April 2020, as the pandemic upended work and life around the globe, Gov. Larry Hogan of Maryland signed an emergency order allowing mail-in ballots to be counted ahead of the election.

That order has since expired and state lawmakers have tried unsuccessfully to update their election rules. In April, lawmakers passed legislation that would, among other things, allow for mailed ballots to be processed before Election Day, not after. But Mr. Hogan vetoed it, saying the legislation failed to include “basic security measures such as signature verification” and “does nothing to address ballot collecting.”

That left Maryland election officials with the unenviable task of handling pandemic-era levels of mail-in ballots with prepandemic rules.

In 2018 — the last midterm election year — Maryland voters sent in a little more than 30,000 ballots to be counted, according to figures from the State Board of Elections. This year, as of July 13, more than 161,000 ballots had been received.

Ms. Duncan’s advice for the public: “Be patient for the results. We are methodical in our process.”