Study Objectives: Poor adherence undermines the effectiveness of positive airway pressure (PAP) therapy for sleep apnea. Disparities exist in PAP adherence by race/ethnicity and neighborhood socioeconomic status (SES), but the etiology of these differences is poorly understood. We investigated whether home environmental factors contribute to PAP adherence and whether identified factors explain disparities in adherence by SES. Methods: Adult patients with sleep apnea were surveyed at clinic visits about their sleep environment. Medical records were abstracted for demographic data, sleep apnea severity, comorbidities, and objective PAP adherence. We evaluated the association between aspects of home sleep environment with PAP adherence using multivariate linear and logistic regression, and assessed effect modification by SES factors. Results: Participants (n = 119) were diverse, with 44% nonwhite and 35% uninsured/Medicaid. After adjusting for age, sex, race/ethnicity, insurance, neighborhood SES, education, and marital status, participants who endorsed changing sleeping location once per month or more (18%, n = 21) had 77% lower odds of meeting PAP adherence criteria (> 4 h/night for 70% of nights) and less PAP use (median −11 d/mo, 95% confidence intervals −15.3, −6.5). Frequency of sleeping location change was the only environmental factor surveyed associated with PAP adherence. Conclusions: Frequent change in sleeping location is associated with reduced PAP adherence, independent of sociodemographic factors. This novel finding has implications for physician-patient dialogue. PAP portability considerations in device selection and design may modify adherence and potentially improve treatment outcomes. Prospective investigation is needed to confirm this finding and inform design of possible interventions.