Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer-related death among women in Puerto Rico (PR). The purpose of this study was to identify factors associated with never screened status among a sample of women nonadherent to the 2013 American Cancer Society guidelines. The inclusion criteria for this study were being a woman (1) aged [greater than or equal to]40 years old and (2) nonadherent to breast cancer screening guidelines. We used baseline data from participants (N = 300; aged [greater than or equal to]40 years old) enrolled in the intervention trial "Cultivando la Salud," implemented in Canóvanas, Puerto Rico, from 2012 to 2014. We used multivariate logistic regression models to identify factors associated with never screening status, adjusting by sociodemographical variables and psychosocial constructs about mammography (self-efficacy, beliefs about mammography pros [benefits] and cons [disadvantages], and subjective norms) as well as by health care insurance, usual source of care, and Pap test adherence. Among nonadherent women, 18.0% reported never having a mammography. Never screened women were significantly younger than previously screened women (adjusted prevalence odds ratio [aPOR] = 7.32, 95% confidence interval (CI): [2.38, 22.50]) and almost four times as likely to have the governmental health plan (GHP; aPOR = 3.78, 95% CI: [1.15, 12.46]). In addition, never screened women perceived more cons (disadvantages) to mammography than previously screened women (aPOR = 1.81, 95% CI: [1.18, 2.78]). We found that women who were younger, had GHP insurance, and had higher levels of beliefs against mammography were more likely to have never been screened. Results from this study can be used to target never screened women with health education messages addressing perceived cons of mammography. Additionally, women with GHP insurance may experience disparities in health care access and should be targeted with policies that facilitate access to mammography screening.