Background: MS-CQI is the first multi-center improvement research collaborative for MS care. MS-CQI was a three-year study (2018-2020) to evaluate system-level performance variation and improve MS population health outcomes. Four MS centers participated, following approximately 5,000 people with MS (PwMS). Here we describe an outreach effort to improve participant engagement in the MS-CQI research collaborative. MS-CQI was a three-year improvement study (2018-2020). Objectives: To improve participant experience and engagement in a multi-year research study that is known to often get affected by participant fatigue and decreased rates of participant engagement, especially in the final months of a study. Methods: During Year 3 of the study, a lead team composed of a Person with MS (PwMS), 3 nurses and a project manager conducted outreach calls to participants in the patient-reported outcomes (PRO) component. Results: 685 (98.5% of total) consented PRO participants were contacted. Many reported barriers of limited internet connectivity and accessing the online PRO platform. Most reported a strong sense of personal connection to the study and an interest in helping. Approximately 10% of those not currently participating were willing to re-engage in the study. Approach, materials and scripts were updated and implemented with a greater focus on the participants perspective to answer key questions: (1) what barriers and facilitators are influencing study participation; and (2) why does my participation matter? Conclusions: Using a co-design approach had significant benefits to study management and engagement. Meaningful inclusion of PwMS in the leadership of this effort was critically important.