This chapter explores the seminal topic of Universal Health Coverage (UHC), an objective within the Sustainable Development goals. It reviews the theory and definitions that shape the current conversation on UHC. The movement from selective primary health care to UHC demonstrates a global commitment to the progressive realization of the right to health. However, access to UHC is limited by barriers to care, inadequate provision of care, and poor-quality services. To deliver UHC, it is critical to align inputs in the health system with the burden of disease. Quality of care must also be improved. Steady, sufficient financing is needed to achieve the laudable goal of UHC.This chapter highlights some important steps taken by countries to expand access to quality health care. Finally, the chapter investigates the theory and practice behind a morbidity-based approach to strengthening health systems and achieving UHC.