Context: The Alberta IMPACT research team is working with other jurisdictions for the scale and spread of a pop-up model of primary healthcare (PHC) service delivery. The pop-up model is complex. Focusing on and sharing the “key ingredients” of the model may assist other jurisdictions interested in implementing the model across different contexts. Objective: To share the “key ingredients” of the pop-up model that emerged in the findings, in order to inform efforts to scale and spread the model to different contexts. Study Design: Community-based participatory action research using a mixed-methods design. Setting and Dataset: Seven pop-ups were held in four different locations in one under-served region of a city of 100,000 in Alberta, Canada. After Action Reviews were conducted with service providers after each pop-up event. Semi-structured interviews were conducted with 12 service providers after the last research team-led pop-up event. Population studied: PHC service providers who provided care at pop-up events. Intervention/Instrument (for interventional studies): A pop-up temporarily brings together PHC service providers in a donated and accessible community space to provide care to people who are underserved by, and struggle to connect with, PHC services. The pop-up model was refined over the two-year implementation period using rapid cycle evaluation approaches to reduce complexity and lessen intervention components. Outcome Measures: The primary study outcome was the design and implementation of the pop-up model for PHC service delivery. Secondary study outcomes include approaches to ongoing meaningful change to the pop-up model, and comprehensive relational care being provided. Results: Using feedback from service providers, intervention components were added, removed, or modified throughout the implementation of the pop-up model. Focusing on (1) approachability of services, (2) ability to reach services, and (3) the ability of people to engage with services results in comprehensive relational care being provided. Conclusions: Community-based interventions are often complex and have many “moving parts.” This complexity often makes it difficult for others to replicate the intervention in different contexts. Focusing on the “key ingredients” we derived from the data can be helpful when the scale and spread of a complex, community-based PHC intervention is being considered.