Emotion regulation plays a central role in individuals' mental health and psychosocial adjustment in life. As autistic youth transition into emerging adulthood, mental health conditions become more apparent due to systemic barriers such as mandatory service disconnection and few available adult services. Accordingly, adequate support and services for young adults on the autism spectrum need to be continued for a smooth transition. Research has found that better emotion regulation skills are associated with better mental health. The current study adapted dialectical behavior therapy emotion regulation skills training and implemented an 8-week group program, which is tailored for autistic young adults. The program is called Skills Improvement on Emotion Regulation for Adults (SIERA), which was modified using feedback from autistic individuals and stakeholders. SIERA was implemented in four groups (n = 19) of autistic young adults. A single-group, pre- and posttest comparison design was used. Autistic young adults who participated in SIERA presented an increase in adaptive emotion regulation skills and psychological flexibility and a decrease in emotion dysregulation. Results indicated that SIERA was an efficacious intervention for autistic young adults in terms of improving emotion regulation skills. Future research directions and implications are also provided. Community Brief Why was this program developed? Emotion regulation is one of the areas in which many autistic individuals present their service needs. Particularly for the young adult population, there are limited resources for emotion regulation. The manualized emotion regulation skills training program was developed based on feedback from autistic individuals, parents, autism researchers, and practitioners to fill the gaps that autistic young adults experience. What does the program do? The current program focuses on learning adaptive emotion regulation skills. Specifically, the program teaches dialectical behavior therapy (DBT) emotion regulation skills in which individuals can learn and explore their emotions, increase emotional resilience, and decrease vulnerability. To that end, individuals can strengthen their emotional awareness, increase their emotion regulation skills, and improve their ability to manage difficult emotions. How did the researchers evaluate the new program? After developing the program, the researchers ran four intervention groups for 19 participants. To evaluate the program, the researchers collected participants' psychological flexibility, DBT skills use, tendency to use emotion regulation skills, and emotional distress to compare the program's efficacy upon completion. In addition, across the eight sessions, the researchers collected a weekly progress checklist before and after each session to monitor participants' weekly growth. What were the early findings? All the participants completed the program (100%) with 99% fidelity. Upon completing the program, participants significantly improved adaptive emotion regulation skills and decreased emotion dysregulation. What were the weaknesses of this project? The current program was initially developed to implement with a face-to-face group. After the first group had been completed, face-to-face groups were not feasible due to the outbreak of COVID-19. Subsequently, the remaining groups were implemented in a synchronous online format. Although the study results showed no significant differences between the in-person and synchronous online groups, online group participants expressed Zoom fatigue, which the in-person group did not experience. What are the next steps? The next step of this intervention is recruiting more autistic young adult participants to increase the sample size. Then, the intervention will be replicated in various settings where diverse autistic adults are involved, such as community colleges, trade schools, community agencies, and state vocational rehabilitation services, to reflect the heterogeneity of autism. How will this work help autistic adults now or in the future? The current study results indicated that participants showed improvement in emotion regulation skills. This program can be helpful for autistic adults by providing opportunities to explore their emotions and learn healthy emotion regulation skills. Consequently, autistic individuals can manage their emotional distress and cope with their emotional challenges in constructive ways. Since the program is manualized, it would also benefit community settings.