Yes, if between WDW resorts. Have heard conflicting info if the Swan/Dolphin participates, so really not sure.
But, they don't transfer it instantly. You drop it at resort A in the a.m., and it gets to resort B, and they tell you it will be there after 4:00 p.m. When you get to resort B, call bell services and have them bring it to your room.
So, you may need to bring along things (meds for one) for the day in your backpack or day bag or whatever container you would have with you in the meantime.