Background: In-Home Supportive Services (IHSS) cares for millions of Medicaid-eligible older adults who are often homebound and socially isolated. Advance care planning (ACP) can be challenging for this population, and IHSS programs may play an important role. Objective: To explore the feasibility of an IHSS ACP program for frail older adults. Design: Semistructured focus groups. Setting/Subjects: Fifty IHSS stakeholders (20 administrators, 9 case managers, 13 in-home caregivers, and 8 clients) participated in 10 focus groups in San Francisco. Measurements: Qualitative thematic content analysis by two independent coders. Results: Four main themes emerged: (1) Unmet needs: patients' wishes unknown during a medical crisis, lack of education/training for clients and staff; (2) Barriers: conflict of interest and potential medical overreach of IHSS caregivers, lack of billing avenues, time limitations, and cultural, literacy, and language barriers; (3) Facilitators: leveraging established workflows, available technology, and training programs; and (4) Implementation: use a tailored, optional approach based on clients' readiness, focus on case managers not caregivers to prevent conflict of interest; use established intake, follow-up, and training procedures; consider cultural and literacy-appropriate messaging; and standardize easy-to-use procedures, simple scripts, and educational guides, within established workflow to support case managers. Conclusions: An IHSS ACP program is important and feasible for Medicaid-eligible, frail older adults. Implementation suggestions for success by IHSS stakeholders include focusing on case managers rather than in-home caregivers to prevent conflict of interest; tailoring programs to clients' readiness, literacy, and language; creating educational programs for IHSS staff, clients, and community; and standardizing easy-to-use guides and procedures into IHSS workflows.