The World Health Organization (WHO) recently endorsed the proposal for a Decade of Healthy Ageing (2020-2030). The WHO defines "healthy aging" as "the process of developing and maintaining the functional ability that enables wellbeing in older age." Among the strategies for the Decade of Healthy Ageing, the WHO has suggested enhancing intrinsic capacity, promoting functional ability, and implementing the Integrated Care for Older People (ICOPE) package. The WHO has defined steps for ICOPE evaluation and scale-up and is performing a prospective study in 2-3 countries (low and middle income, high income) to test its feasibility in 2021-2022 and a multinational randomized study to validate its clinical efficacy and effectiveness in 2022-2024. Intrinsic capacity and frailty represent two faces of the same coin, with one indicating the reserves of the individual and the other indicating the deficits that accumulate with age. The Integrated Care of Older Patients with Frailty in Primary Care (ICOOP_Frail) study is the first integrated care program for frailty or functional decline in primary care in Korea. The results suggest that the ICOOP_Frail study can be utilized as a reference for ICOPE studies in Korea or at least to provide important findings for the forthcoming ICOPE implementation study in Korea.