Update: All precincts have been reported by the Secretary of State’s office, showing Hillary Clinton and Donald Trump on top in the Missouri primary.
Both Clinton and Trump lead in their parties by less than half a percent, amounting to a virtual tie. As yet, neither has been formally declared a winner in Missouri.
Clinton has been declared the winner in Florida, North Carolina, Ohio, and Illinois.
Trump has been declared the winner in Florida, Illinois, and North Carolina. John Kasich won his home state of Ohio.
Marco Rubio ended his campaign earlier in the evening after losing the Florida primary to Trump.
Candidates in both parties have campaigned hard in Missouri in recent days, and voters are casting their ballots for their choices on Tuesday.
Hillary Clinton and Bernie Sanders are the top choices for voters filling out Democratic ballots. Clinton currently leads Sanders in total delegates by a count of 1,235-580.
On the Republican side, Donald Trump leads the pack, followed by Ted Cruz, Marco Rubio and John Kasich. Trump currently has 469 delegates, Cruz has 370, Rubio has 163, and Kasich has 63.
Florida, Ohio, North Carolina, and Illinois are also holding presidential primaries today.
Click here for live coverage of the primaries from ABC News.