Studies show that women with high BMI are less likely than thinner women to seek healthcare. We aimed to determine the mechanisms linking women’s weight status to their healthcare avoidance. Women (N = 313) were surveyed from a U.S. health-panel database. We tested a theory-driven model containing multiple stigma and body-related constructs linking BMI to healthcare avoidance. The model had a good fit to the data. Higher BMI was related to greater experienced and internalized weight stigma, which were linked to greater body-related shame. Internalized weight stigma was also related to greater body-related guilt, which was associated with higher body-related shame. Body-related shame was associated with healthcare stress which ultimately contributed to healthcare avoidance. We discuss recommendations for a Weight Inclusive Approach to healthcare and the importance of enhancing education for health professionals in weight bias in order to increase appropriate use of preventive healthcare in higher weight women.