Home modifications encompass a range of structural changes and adaptive features to the living environment that support safety, autonomy, and community participation for older adults and people with disabilities. This entry summarizes the evidence-based principles and impacts of home modifications. It discusses the foundational concept of Universal Design, which integrates accessibility into core housing design. This entry also reviews empirical evidence demonstrating that modifications, such as installing ramps, grab bars, and nonslip flooring, can significantly reduce caregiver burden, decrease the risk of falls, and improve self-rated health. The critical importance of a client-centered process, often facilitated by an occupational therapist, is emphasized to ensure modifications are tailored and effective. While financial and systemic barriers to access exist, economic analyses consistently show that home modification programs are highly cost-effective, offering a significant return on investment by reducing medical and long-term care costs. The entry also explores the emerging role of smart home technologies in fostering greater independence. Overall, home modifications are a powerful intervention for promoting health equity and enabling individuals to thrive in their chosen communities.