The following five characterization tools have been developed for use in the Gender and Autism Program (GAP) (click "Read More" below to access links to each measure; click the three dots on the top right corner of each measure's web page to download the tool). These characterization tools are used to identify youth and family needs and goals; characterize strengths, resilience factors, and potential risk factors; and develop a plan for supporting the young person, particularly in relation to autism and gender diversity. These tools also have broader applications than our program, alone. The order in which the five tools are listed is the same order in which they are administered during evaluations in the GAP, starting with the most closed-ended, concrete questions (the Gender Self-Report) and moving toward more open-ended question formats, culminating in the Gender Development Questionnaire, which consists primarily of open-ended interview questions. The fifth measure (the Transgender Youth Fertility Attitudes Questionnaire) is used when a young person is considering gender-affirming medical care that could impact fertility. This approach of starting with closed-ended questions aligns with clinical observations that autistic youth may be more comfortable answering closed-ended questions over open-ended questions. We start with closed-ended questions to help build rapport and leave the more open-ended questions for later in the interview when the young person may feel more comfortable and ready to engage with open-ended formats. Importantly, each of the tools is administered live with the evaluator, as commentary from the young person regarding the questions (e.g., elaborations, explanations, voiced challenges that a young person may have with the questions) has been found to be clinically important in understanding a young person’s experience of gender, including how they think about gender. Each of the tools is administered by the evaluator presenting the questions on a shared screen and reading them aloud to the young person depending on the young person’s preference. **Gender Self-Report (GSR)**: The GSR is a 30-item multiple choice self-report measure capturing multidimensional gender diversity. Specifically, it focuses on the inner gender experience of a person instead of gender dysphoria. Psychometrically, the GSR provides three gender values (Female-Male Continuum, Nonbinary Gender Diversity, Binary Gender Diversity) as standardized values ranging from 0 to 1. For interpretation of the three domains, please see the original paper presenting the GSR as well as the GSR calculator. We include the [GSR report form][1], the [calculator][2], and the [published study][3] presenting the GSR. **Gender Expression Measure (GEM)**: The GEM is a self-report tool consisting of 17 to 22 questions. The number of questions presented depends on the youth responses, with branching logic for some questions. The GEM captures broad gender-related experiences, intentions and goals, as well as areas of perceived unmet need. Gender-related topic areas include gender exploration, dress and style, name, pronouns, speaking voice, and physical gender intervention goals. Here is a [PDF][4] of the questions. In our administration, these questions are programmed into the REDCap question presentation and data capture system. **Gender Barriers Questionnaire (GBQ)**: The GBQ consists of 22 multiple choice questions capturing a range of barriers/obstacles neurodivergent gender-diverse youth may experience in moving forward with their gender-related goals. The GBQ is intentionally administered after the GEM, as this allows the young person to think about their gender experiences and needs (including unmet needs) and then immediately to consider potential barriers to achieving their needs with the GBQ. The first five items of the GBQ focus on common executive function-related barriers. As demonstrated in one study, the summary score for these items in transgender youth was a primary predictor of suicidality (e.g., higher levels of neurodivergence-related barriers predicting suicidality). The GBQ includes four domains of measurement: planning, flexibility, and communication skills; worries and/or other peoples’ reactions; “I’m still exploring what I need”; and other possible barriers. We present a PDF of the GBQ [here][5]. The GBQ was included in [this study][6]. **Gender Development Interview**: The Gender Development Interview is an open-ended interviewing tool consisting of 25 discussion areas. The interview was developed as part of one of the first qualitative studies of autistic transgender youth which identified primary themes and experiences described by the young people. The Gender Development Interview is administered late in the sequence of tools as the open-ended questions may be more demanding of cognitive integration skills; therefore, these questions are saved for a point in the interview sequence where rapport has been best established. Topic areas include gender development history, gender-related support needs, future goals and planning, and experiences of being neurodivergent and gender-diverse. Primary thematic areas identified through use of this interview are highlighted in [this study][7]. We present a PDF of the Gender Development Interview [here][8]. **Transgender Youth Fertility Attitudes Questionnaire (TYFAQ)**: The TYFAQ is a 14-item self-report questionnaire developed to explore a young person’s knowledge about and attitudes toward fertility and fertility preservation in the context of gender-related medical care. Separate youth and parent/caregiver forms are available. The [TYFAQ][9] is administered with young people contemplating gender-affirming medical care. The measure development study is available [here][10]. [1]: https://osf.io/c43q5 [2]: https://osf.io/qfgeu [3]: https://pubmed.ncbi.nlm.nih.gov/36716136/ [4]: https://osf.io/ehjk9 [5]: https://osf.io/74fzd [6]: https://pubmed.ncbi.nlm.nih.gov/34121545/ [7]: https://pubmed.ncbi.nlm.nih.gov/30140984/ [8]: https://osf.io/mjszw [9]: https://osf.io/492wk [10]: https://pubmed.ncbi.nlm.nih.gov/29033160/