CR is a cornerstone of secondary prevention for cardiovascular disease, offering well-established benefits across mortality, hospital readmission, functional capacity, and quality of life. Despite Class I guideline endorsements and decades of supporting evidence, CR remains vastly underutilized, particularly among women, racial and ethnic minorities, older adults, and individuals in low-resource settings. This review synthesizes the current evidence base for CR, with emphasis on disease-specific benefits across different cardiovascular diseases, and highlights recent data on its role in expanding populations, including patients with HFpEF, older adults, patients with advanced heart failure, and those undergoing transcatheter interventions. We also examine persistent barriers to CR access and participation, including system-level and referral limitations, as well as patient-level disparities by age, sex, race and ethnicity, and socioeconomic status. Building on this, we explore innovative delivery models and recent policy initiatives such as hybrid programs and reimbursement reform, all designed to expand access, promote equity, and modernize CR delivery. The findings underscore the need for continued investment, advocacy, and innovation to ensure equitable access to CR and its life-saving benefits across the full cardiovascular care continuum.