An evaluation approach where the agency first checks whether your proposal is technically acceptable, pass or fail, with no credit for exceeding the bar, and then awards to whoever cleared that bar at the lowest price. It rewards a lean, compliant proposal over an impressive one, and it is less forgiving of underbidding than best value, because there is no technical score left to cushion you. Section M of the solicitation will say plainly whether a buy is LPTA.

In a sentence

"Award will be made on a lowest price technically acceptable basis." Meeting every requirement matters, exceeding them does not, so stop polishing once you have cleared the bar and put the remaining effort into price.