Port Authority officials say the terminal serves more than 65 million people a year and is at capacity during rush hours.
The study will include plans to possibly replace the terminal or repair and improve it. Construction would have to be phased in to prevent disrupting operations.
Officials will also examine ways to create a new bus staging area on Manhattan's West Side to limit the amount of buses idling on city streets.
Plans also call for designing a sustainable funding strategy that would include the development of air rights above the Port Authority Bus Terminal to generate revenues to offset costs.