The 88th running of the French endurance classic is set to take place on September 19-20 after the health crisis forced the ACO to abandon its usual mid-June date.
Last year's race attracted over 250,000 fans to La Sarthe, but current government restrictions on large gatherings have forced a change of plan for this year's event.
On Tuesday morning, the ACO issued a statement clarifying that only its members and those that had purchased a ticket on or before Monday June 29 will be guaranteed entry to the circuit, with ticket sales suspended "in the hope that conditions improve" ahead of the race.
ACO President Pierre Fillon said: "We have always been at the forefront of technological innovation to improve safety and sustainable mobility. Responsibility is one of our founding principles. We are therefore sure that our loyal spectators will understand our position and support our decision.
"We will not be breaking any attendance records this year. However, all the magic of the race will remain intact and the spectator experience – trackside or from a distance – will remain world-class.”
Earlier this month, a condensed revised schedule for Le Mans race week was revealed, with track action kicking off with practice on Thursday instead of on Wednesday.
In addition, it is expected that the traditional drivers' parade in downtown Le Mans on Friday evening will not take place unless the French government rules change, as it would fall foul of the current restriction on gatherings that mandate a maximum of 5,000 people.