Employment outcomes have long been emphasized as a primary transition outcome for individuals with extensive support needs. To develop appropriate annual individualized education plan (IEP) goals for transition, appropriate transition assessments must be administered to guide the process (Prince et al., 2014). As such, transition assessment is a required component of the IEP according to the Individuals with Disabilities Education Act. Unfortunately, very few appropriate formal transition assessments, including validity and reliability evidence, currently exist for individuals with extensive support needs (Deardorff et al., 2020). To fill this need, the Transition Assessment and Goal Generator—Alternate (TAGG-A) was created. The purpose of this article is to report on validity evidence related to the structure of the professional version of the assessment, the TAGG-A-P, as a necessary part of the larger project. The alignment of the resulting constructs with employment outcomes is discussed.