Our district offers a self-contained gifted program to students scoring 99% on one or more of three general areas in their screening test (a matrix of the CogAT/ITBS) and outside testing is also accepted. The program is space limited, test scores are only a pre-req and a written application is required as part of the process. Our DS6 was tested in K last year, scored 99% in all three areas and was wait-listed for the program.
In district information, parent forum discussions and other info I have gathered, the program is characterized in descriptions and in name as an alternative program. An alternative for those students for whom the neighborhood school is not working. The program retention rate is extremely high and some parents comment that there is simply no other option, public or private, save homeschooling that is an option for their student. I do not have direct knowledge of the application review criteria and can only guess at this point. However, difficulty making age peer friends, behavioral and emotional issues, high asynchrony - the frustrations and challenges that many of the parents on this board face on a daily basis - very likely make up many of the reasons for interest in the program and are reflected in the applications that are accepted.
We are thankful that our DS is happy and doing well in our neighborhood school and, for now, it is our least worse option. We also are supporters of the self-contained program and hope that it can grow beyond it's current constraints so that it can serve a greater number of students.
(As an aside, this topic prompted me to post for the first time. The discussions on this board have been of great help to us -- Thank you!)