Objective: We examined the roles of oncology providers in advance care planning (ACP) delivery in the context of a multidisciplinary cancer program. Methods: Semi-structured interviews were conducted with 200 women with recurrent and/or metastatic breast or gynecologic cancer. Participants were asked to name providers they deemed important in their cancer care and whether they had discussed and/or completed ACP documentation. Evidence of ACP documentation was obtained from chart reviews. Results: Fifty percent of participants self-reported completing an advance directive (AD) and 48.5% had named a healthcare power of attorney (HPA), 38.5% had completed both, and 39.0% had completed neither document. Among women who self-reported completion of the documents, only 24.0% and 14.4% of women respectively had documentation of an AD and HPA in their chart. Completion of an AD was associated with number (adjusted odds ratio [AOR] = 1.49) and percentage (AOR = 6.58) of providers with whom the participant had a conversation about end-of-life decisions. Participants who named a social worker or nurse practitioner were more likely to report having completed an AD. Participants who named at least one provider in common (e.g., named the same oncologist) were more likely to have comparable behaviors related to naming a HPA (AOR = 1.13, p = 0.011) and completion of an AD (AOR = 1.06, p = 0.114). Conclusions: Despite the important role of physicians in facilitating ACP discussions, involvement of other staff was associated with a greater likelihood of completion of ACP documentation. Patients may benefit from opportunities to discuss ACP with multiple members of their cancer care team.