I assume you are talking about installing a Level II EVSE inside your garage or attached to the outside of your home. Short answer, yes. There needs to be a service disconnect for any 240V equipment, for example a heat pump or air conditioner compressor always has a nearby service disconnect box. When you have an EVSE that has a plug such as a NEMA 14-50 or 6-50 the plug is the service disconnect mechanism in case the equipment needs to be serviced. Note: a plug-in type EVSE can only be installed indoors (a garage is considered indoors.)
All outside installations of EVSE need to be hard wired, hence the need for a nearby service disconnect box. The service disconnect box needs to be within line of sight to the EVSE. Here is an instructional video, the service disconnect box is discussed about 4:20 into the video. https://www.youtube.com/watch?v=R61LyUJEupM
One possible exception to the need for a separate service disconnect box would be if your electrical service panel was located in your garage and your EVSE was hard wired to the service panel and installed inside your garage. Then the breaker switch at the service panel would be within line of sight of the EVSE and would satisfy the requirement for a service disconnect that was within line of sight of the EVSE.