BACKGROUND: Facilitation is an implementation strategy that can help primary care practices improve healthcare quality and build quality improvement (QI) capacity when delivered in a flexible manner by trained professionals. Practice ownership is associated with use of QI. However, little is known about how practices of different ownership participate in external facilitation, and this could inform future initiatives. OBJECTIVE: Using data from EvidenceNOW, we examined how practice ownership influences participation in external facilitation. STUDY DESIGN: We used an iterative mixed-methods design. PARTICIPANTS, APPROACH, AND MEASURES: We collected data from practices on practice characteristics (e.g., location, size, payer mix) and ownership type via surveys and from facilitators on the number of hours, encounters, and months each practice had with a facilitator via facilitation logs. Using multivariable linear regression, we examined the association between facilitation and ownership (n = 1117 practices). We conducted semi-structured interviews with EvidenceNOW leadership (n = 12) and facilitators (n = 51) and observed facilitators in a subset of practices (n = 64); we analyzed this qualitative data for patterns of facilitation. KEY RESULTS: In the fully adjusted model, differences by ownership were non-significant; FQHCs, however, had significantly less participation in facilitation than clinician-owned practices across two measures (unadjusted difference: - 2.83, p < 0.01 for number of encounters, and - 2.04, p < 0.01 for number of months with encounters). Qualitative data showed that Health System and FQHC ownership influenced types of practices enrolled in EvidenceNOW, and suggested that in these practices lower autonomy and greater complexity compared to clinician-owned ownership influenced facilitation participation patterns. CONCLUSIONS: Practice ownership shaped how but not how much practices participated in external facilitation. This finding highlights the importance of tailoring facilitation approaches based on ownership-related characteristics in future QI initiatives.