Each National Olympic Committee (NOC) was permitted to enter a maximum of two qualified athletes in each individual event, but only if both of them had attained the Olympic Qualifying Time (OQT).[2] For this event, the OQT was 4:12.50. World Aquatics then filled the rest of the event places with athletes qualifying through universality; NOCs were given one event entry for each gender, which could be used by any athlete regardless of qualification time, providing the spaces had not already been taken by athletes from that nation who had achieved the OQT.[2][3] In total, 16 athletes qualified through achieving the OQT, while no athletes qualified through universality places.[3]
Competition format
The competition consists of two rounds: heats and a final. The swimmers with the best 8 times in the semifinals advance to the final. Swim-offs are used as necessary to break ties for advancement to the next round.