The contest began on 25 June and the winner will get $35,000 in total prizes along with public recognition and a winner's certificate.
The three companies will develop, build and fly the landers and the contract for the initial 10-month period is $967 million.
The Dragon XL spacecraft will carry research supplies that will help future astronauts on the moon collect lunar samples.
They can go on any manned mission and will join the ranks of about 500 people who have been to space.
After 2 years of basic astronaut training, the new batch is ready to train at the ISS and for the Artemis program after graduating 10 January 2020.
NASA wants to return to the moon with the Artemis mission and they are building a smaller version of the ISS to orbit the moon.
The Artemis mission will also feature an unpressurized rover for astronauts to move around faster in.
NASA views its return to the Moon as a proving ground for an onward mission to Mars in the 2030s.
The test lasted for 12 minutes and the system never left the ground during the simulation.
Former astronaut Ken Bowersox will be acting head said NASA administrator Jim Bridenstine.
If the $1.6 billion funding doesn't come through, NASA will revert to its original plan to land in 2028.
Artemis is still in very early stages of planning, and yet to receive Congress's approval for funding.