The card is not a pass, it is just what it says it is a Guest Assistance Card.
It is a card that communicates some basic information to cast members about your needs so that you don't need to repeat the same information over and over.
There is further information (a lot of it) in post #6 of the disABILITIES FAQs thread. There is a link in my signature to the disABILITIES FAQs thread.
Here is some information emailed out by Disney about GACs:
The Guest Assistance Card is a tool provided at all four WALT DISNEY WORLD Resort Theme Parks to enhance the service we provide to our Guests with disabilities. It was designed to alert our Cast about those Guests who may need additional assistance. The intent of these cards is to keep Guests from having to explain their service needs each time they visit an attraction.
The Guest Assistance Card is available to our Guests with non-apparent, special assistance needs. However, the intention of this card has never been to bypass attraction wait times, or to be used by Guests with a noticeable service need.
Guests with an apparent mobility concern, such as Guests using wheelchairs, canes, crutches, etc., or Guests with service animals, do NOT need a Guest Assistance Card. These Guests should be directed to follow the attraction entrance procedures for guests using wheelchairs, as outlined in the Guidebook for Guests with Disabilities.
A Guest with a specific need for assistance can request a Guest Assistance Card at any Theme Park Guest Relations location. To accommodate the individual needs of our Guests, we ask that all Guests discuss their assistance requests with a Guest Relations cast member prior to the card being issued. The Guest Relations Cast Member will discuss the available service options with the Guest and provide written instructions for our cast on the Guest Assistance Card. The Guest will be directed to present the Guest Assistance Card to the Greeter or first available Cast Member at the attraction and await further directions for their experience.[/SIZE]
It says right on the card that it is not meant to shorten or eliminate waits in line. Very often, it does not and can make your wait longer. You should be waiting in an area/conditions that meet your needs though.
HIPPA (which stands for Health Insurance Portability and Privacy Act) is often brought up as a reason that no 'proof' is needed for getting a GAC, but this is not true.
HIPPA provides for Health Insurance Companies and Health Care Providers to share information that is need for care and limits/prohibits sharing of information that is not directly needed for care. It
only applies to Health Care facilities and places that provide health care (for example; insurance companies, hospitals, pharmacies, medical equipment companies) and it only applies to those sharing information with each other. If you, as a patient want to share the information, there is not a problem.
A GAC is not a front-of-the-line pass. Only severely ill Make-A-Wish kids will be accommodated like that. A GAC can even lengthen your wait at some attractions.

True
Cathryn, a GAC is the FURTHEST thing from FoL acccess. In fact sometimes you wait LONGER having one. A GAC is there to provide a safe, reasonable alternate access to rides and attractions.. ..perhaps a quiet, out of the way area to wait until your turn in line comes up. or another lone that is less crowded or doesn't have stairs or something.
the actual IEP is not required, you just need to be able to say what the limitations are and what is a good workaround for your individual needs.
Yes.
Some examples of longer waits that we have experienced have included:
- a 35 minute wait at Small World when people in the regular line were walking right on and some boats were being sent out half full because people were not coming fast enough to fill them. (The alternate waiting area at Small World is the only way to use a wheelchair at that attraction).
- a 30 minute wait at Spaceship Earth when the posted wait time at the queue was 5 minutes (again, because we have a person using a wheelchair, we had to use the alternate waiting area because that is the only accessible entrance).
A GAC does not provide of line access, and not all GACs do the same thing. For instance, I am getting a GAC next time which will allow me to avoid waiting in lines in direct sun (I will wait elsewhere in the shade for them) because I have a medication-induced sun-sensitivity.
Every person is different. My disorder is a genetic defect, and requires me to use a top-end $15,000 power wheelchair. A friend of mine with the same disorder requires Dr Scholls insoles! I know people who are ADD/ADHD who can handle lines fine, and I know others who go into a meltdown.
Are there people who abuse the GAC system? Yes. But I believe they are a small minority, and the system is too precious to risk losing it due to those few people. Six Flags got rid of their system entirely to avoid abusers, and now I can never go there, because there is no way for me to handle the parks.
Trust me, I hate abusers more than people with no need for accommodations. I am definitely one of the people who suffers every time I have to wait longer behind someone who doesnt really need their GAC or wheelchair (they only allow 2-3 people with a wc or GAC on at a time, for safety reasons). Oh, and btw, those wheelchair lines are AFTER I wait in hte regular line.
I suggest people go read the Disabilities board FAQs. There is a lot of great info over there.

Just how a particular GAC is handled for an attraction depends on what the person's needs are, what is available at that attraction and what conditions are at that time.
ALL WDW attractions have wheelchair accessibility (i.e. a way to access the attraction without stairs or things that someone in a wheelchair can't get thru). Most attractions have wheelchair accessibility thru the regular (Mainstream) line. Not all attractions have alternate entrances or waiting areas and in many cases, the alternate waiting area is a roped off area next to the 'regular' waiting area.
Here are some pictures of alternate waiting areas:
Laugh Floor - this is the area right before entering the theater. By the time the show will begin, the area on the left side of the chain will be filled with people waiting for the show. The small area on the right side is the special needs waiting area.
This is the alternate area for Circle of Life in Epcot. People without special needs wait in the area on the left of the rope.
Honestly, having never had a child with a learning disability/behavior problem, it's hard for me to understand what needs your family may have. Only you can decide what's right for you guys.
Here are a couple thoughts, though. We usually tour the parks at a less crowded time of year. We utilize rope drop and fast pass, and very rarely find a situation where we are waiting longer than 20-30 minutes for most attractions. Again, I can't say for sure, but if I had a child with mild special needs, I think I might prefer to take the opportunity to treat the child like a regular kid on vacation. They may be "labeled" at school and need special help, but at Disney, they can be just like everyone else. I think I would prefer that to going out of my way to make a big deal out of their differences by obtaining the GAC and figuring out how to use it on every ride. (This is definitely not addressing a situation where clearly some extra help is needed!) Just a thought, not intended to offend!!!
Many people, even with children with severe needs, have found that the suggestions I bolded from your response are more helpful than a GAC.
Many people also utilize touring plans like TourGuide Mike that help them be in the least busy part of the park at the least busy times.
Knowing when to be where is more helpful to many people than having a GAC because the GAC only assists with attractions - you still need to deal with the general busy-ness and crowded conditions of the park. Going when and where it's not busy is much more helpful.