MGM Resorts, which includes Borgata Hotel & Casino in Atlantic City, formally terminated around 18,000 employees.
The country's largest employer of casino workers says the decision is in response to COVID-19.
MGM informed the impacted workers last week that their furloughs would become permanent job terminations as of Tuesday.
The terminations reduce the company's domestic employment total by about 25%.The terminations affect around 3,100 casino employees at the Borgata.