Expansion continued in the 1950s, when prominent hotel architect Morris Lapidus was hired to design new modern style guest wings.

At the Concord, Lapidus worked with architect-interior designer Theordor Muller on interiors for lobbies, dining spaces and night clubs.

Lapidus employed his signature floating stair design in the rotunda to give guests an opportunity to make a grand entrance.

Winarick felt that more was needed, and the Lapidus-designed Imperial Room seated three thousand in a nearly-circular space: perhaps the largest in the Catskills, and a popular venue for major entertainers.

A Lapidus-designed 1959 wing featured 210 rooms with projecting bay windows and his-and-her bathrooms, each with a dressing area.

In 1999, the property sold "for $10.5 million to a partnership led by Joe Murphy, with Louis R. Cappelli as a silent partner".

The Concord was used several times over the years by the New York State Association of Fire Chiefs for their annual convention and trade show.

[9] On May 5, 2011, the owners of the Mohegan Sun casino in Uncasville, Connecticut announced a competing joint venture with Cappelli Enterprises Inc. to build a $600 million racino on the site of the former hotel.