A total of 1,058 delegates - including 367 Republican and 792 Democratic delegates - will be up for grabs as five states and one territory go to polls on 15 March.
The frontrunners will battle it out in Florida, Illinois, Missouri, North Carolina, and Ohio and the territory of Northern Mariana Islands, which will hold a Republican primary.
1. Florida (Polling closes at 4:30 AM IST)
Democrats (246 delegates); GOP (99 delegates)
What the polls say: Most polls (Monmouth, Quinnipiac, Florida Times-Union, among others) project a Donald Trump victory, with Marco Rubio coming in at second place despite it being his home-ground. According to RCP average, Hillary Clinton will sweep Florida.
Democrats (84 delegates); GOP (52 delegates)
What the polls say: Missouri is expected to go to Trump, with Ted Cruz coming in at a close second. On the Democrat side of affairs, Bernie Sanders is expected to take Missouri. (RealClear Politics)
3. North Carolina (Poling closes at 5:00 AM IST)
Democrats (121 delegates); Republican (72 delegates)
What the polls say: PPP(D) projects Trump and Clinton winning North Carolina.
Democrats (159 delegates); Republicans (66 delegates)
What the polls say: According to RealClear Politics polls, Clinton is expected to sweep Ohio, while Kasich is expected to lead with a 35.5 per cent lead over Trump.
5. Illinois (Polling closes at 5:30 AM IST)
Democrats (182 delegates); Republican (69 delegates)
What the polls say: PPP(D) projects Trump and Clinton sweeping Illinios.
Republicans (9 delegates)