[Correction Notice: An Erratum for this article was reported online in Psychiatric Rehabilitation Journal on May 20 2021 (see record 2021-48272-001). In the original article, the following acknowledgments were missing from the author note: : "The contents of this article were developed under a grant from the National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR; Grant 901F0065-02-00; Mark S. Salzer, principal investigator). However, the contents do not necessarily represent the policy of the U.S. Department of Health and Human Services, and endorsement by the federal government should not be assumed. The authors are grateful to Kevin Frech, Stephany Wilson, Alison Weigl, Jared Pryor, David Glogoza and Katie Pizziketti for their assistance with data collection and analysis and to Alex Fechner for providing his implementation of the ST-DBSCAN algorithm in RapidMiner." All versions of the original article have been corrected.] Objective: The purpose of this study was to determine if environmental novelty was associated with neurocognitive function among adults with serious mental illness. Method: Participants were recruited from community mental health centers (n = 117), and received a Global Positioning System (GPS) enabled cellular phone for 13 days. Data were also collected on cognitive function and recent participation in community-based activities. Independent samples t-tests were conducted to identify differences in neurocognitive function between participants who predominantly stayed in their homes ("homebodies") versus those who ventured more often from their homes ("venturers"). Analyses were also undertaken to identify if the nature of community participation activities mediated the relationship of neurocognitive function to group membership. Results: Overall, 74% of GPS signals were from participants' home residence. Homebodies demonstrated significantly poorer cognitive function than venturers, and this relationship was not mediated by a number of unique destinations or breadth of community participation activities. Conclusions and Implications for Practice: This study identified a subset of adults with serious mental illnesses who left their homes infrequently and who demonstrate significantly poorer cognitive function than those who left their homes more frequently. Spending extensive amounts of time in an unchanging environment may be a contributing factor to poor cognitive function, and a potential area for intervention. (PsycInfo Database Record (c) 2022 APA, all rights reserved).