Medication literacy reflects the specific literacy skills necessary to act on medication-related information. A comprehensive and clear conceptual model that reflects medication literacy is lacking. Conceptual models describe the components that represent a construct, allowing for its understanding and providing a rationale for its measurement. To propose a conceptual model to support the development of an instrument to measure medication literacy. This is a three-phase methodological study. A literature review was conducted to identify the components that should be part of the preliminary conceptual model. Subsequently, the importance of its components was judged on a Likert-5 scale. Then, the model was refined, and the dimensions and subdimensions of medication literacy were defined. Forty-five experts were included, with a mean age of 39.9 (SD = 10.5) years, most of them females (86.7%) and pharmacists (80%). All components of the preliminary conceptual model were considered important to extremely important by most experts. "Dosing information", "medication name", and "processing the information received about their medication and acting upon medication instructions" were the components considered most important. In the refinement phase, we identified that the construct has four dimensions – functional literacy, communicative literacy, critical literacy, and numeracy, which include the subdimensions to access, understand, evaluate, calculate, and communicate medication-related information. The conceptual model allowed identifying the components that represent medication literacy, which will support the development of an instrument for measuring the construct in Brazil.