Background: The benefits of friendships among peers with and without intellectual and developmental disabilities are well supported by research. However, little is known about the nature of these inclusive friendships in inclusive college courses. Method: We explored the perspectives of peers on the development of authentic friendships among peers with and without intellectual and developmental disabilities in inclusive college courses in the United States. We used a sequential, explanatory, transformative mixed methods-grounded theory research design. We integrated quantitative (N = 44) and qualitative (N = 8) findings using blended analysis to inform a preliminary grounded theory of inclusive and reciprocal friendships. Results: Quantitative findings suggest two relationships and one predictor of peers' perceived social engagement. Qualitative findings resulted in five themes that promote friendships. Conclusions: We propose that the context for developing inclusive friendships could be fostered using the preparation and actions stages of the grounded theory model.