Combination products (CPs) combine two or more product types such as drugs, devices, and/or biological products for increased safety and clinical effectiveness. The emergence of innovative CPs poses new challenges for regulatory agencies in assigning jurisdiction for premarket review and oversight. In US, the 1990 Safe Medical Devices Act defines and provides classification criteria for CPs, and the US government has developed a regulatory process through multiple acts, including the 21st Century Cures Act of 2016. Meanwhile, regulators in the European Union (EU) and the Republic of Korea have recently recognized the importance of premarket pathways for CPs. The European Medicines Agency (EMA) has issued guidelines and explanations on compliance issues related to drug-device CPs under MDR. EMA doesn't have the definitions of CPs, but uses the term drug-device combination products (drug-device CPs). CPs are categorized as drugs or medical devices, which follow their relevant regulatory framework. The Ministry of Food and Drug Safety (MFDS) in Korea has legal definitions of CPs under the Notice of the MFDS. CPs are designated as drugs or medical devices according to their primary mode of actions (PMOA) and follow regulatory processes through the framework of drugs or medical devices. This study aims to comprehensively summarize the regulatory oversight of CPs by analyzing the regulatory policies and legal frameworks in the US, the EU, and Korea. The regulatory challenges encountered when developing CPs are also discussed. With specific emphasis on the combination of drugs and devices, this study provides in-depth insights into the regulatory landscape, shedding light on the unique challenges associated with the development of CPs for this particular intersection of drugs and devices.