Older Veterans with medical complexities represent one of the most vulnerable patient populations. This large and growing proportion of Veterans Health Administration (VHA) beneficiaries are more likely to live in rural areas, experience social isolation and loneliness, and be physically inactive. Thus, medically complex older Veterans are at greater risk for progressive declines in function, lower quality of life, and frequent care needs. While the VHA has established outpatient programs to address rehabilitation needs, these programs tend to serve disease-specific populations (e.g. cardiac, stroke) on an episodic basis. Moreover, these programs often do not meet the needs of medically complex older Veterans, as they typically 1) require in-person attendance, 2) under-dose the physiologic intensity of rehabilitation, and 3) lack self-management approaches for preservation of function. Telehealth platforms offer a solution to redesign rehabilitation models of care for medically complex older Veterans and can aid in overcoming access barriers (rurality, transportation), while also integrating technologies to augment biobehavioral interventions and provide social support. Novel, scalable telerehabilitation approaches targeting medically complex older Veterans are urgently needed to 1) address physiologic impairments using progressive, high-intensity rehabilitation, 2) increase physical activity with biobehavioral interventions which promote self-management, and 3) reduce social isolation and loneliness via social support. Our proposed MultiComponent TeleRehabilitation (MCTR) program addresses current healthcare deficiencies by using a multicomponent approach that includes both high-intensity rehabilitation interventions and self-management interventions that are not part of traditional physical therapy interventions. Therefore, we propose a two-arm, parallel randomized trial using a crossover study design to determine the effectiveness (AIM 1) of a 12-week multicomponent telerehabilitation program to improve physical function. We will also measure Veterans’ clinical outcomes to evaluate the effectiveness of the MCTR program to improve physical activity, health self-management, and self-reported health (AIM 2). Lastly, we will explore the effects of the MCTR program on safety events such as emergency room visits, hospitalizations, falls, and other adverse events (AIM 3). Participants (n=126) will be randomized to MCTR or Control group using computer- generated random blocks, stratified by sex. The MCTR group will participate in the 12-week program consisting of 1) progressive, high-intensity rehabilitation, 2) self-management interventions, 3) social support, and 4) technology supports. The 12-week program is split into two phases: the Active Phase (weeks 1-6) and the Transition Phase (weeks 7-12). The Control group will participate in education and health status update sessions in parallel to the MCTR 12-week program. Following the program, partici...