Floors 31, 32, 33 and 34 of the hotel will be renumbered 56, 57, 58 and 59, said Brian Ahern, a spokesman for MGM Resorts International, which owns the Mandalay Bay.
Stephen Paddock, a 64-year-old retiree, fired on the Route 91 Harvest festival on Oct. 1 from a suite he had rented on the 32nd floor of the Mandalay Bay before taking his own life.
The tower, which is 43 stories tall, had already used an unconventional floor-numbering system before the massacre in which the top four floors were listed as 60-63.