Practical Rules for booking ME.
If you are booking with a
travel agent, then your travel agent can book ME when they make your Disney reservations.
If your travel agent is clueless and says you can't use ME, then 60 days before your trip, you can call DME directly and book with them.
If you are booking directly with Disney yourself, you can book DME with Disney Reservation Center directly.
If you have anything difficult about your reservation, such as different folks arriving different days or different flights, a split stay, some driving, some flying, staying at the airport hotel the night before you arrive, renting a car and going elsewhere first, needing a wheelchair lift, etc, etc, then call DME directly 60 days before your trip and get all the details straight with them. (Unless it's a basic straightfoward reservation, it may get messed up in the transfer between DRC and DME.)