BACKGROUND: Goals of care conversations explore seriously ill patients values to guide medical decision making and often inform decisions about life sustaining treatments. Ideally, conversations occur before a health crisis between patients and clinicians in the outpatient setting. In the United States Veterans Affairs (VA) healthcare system, most conversations still occur in the inpatient setting. Strategies are needed to improve implementation of outpatient, primary care goals of care conversations. METHODS: We plan a cluster randomized (clinician-level) sequential, multiple assignment randomized trial to evaluate the effectiveness of patient implementation strategies on the outcome of goals of care conversation documentation when delivered in combination with clinician implementation strategies. Across three VA healthcare system sites, we will enroll primary care clinicians with low rates of goals of care conversations and their patients with serious medical illness in the top 10th percentile of risk of hospitalization or death. We will compare the effectiveness of sequences of implementation strategies and explore how patient and site factors modify implementation strategy effects. Finally, we will conduct a mixed-methods evaluation to understand implementation strategy success or failure. The design includes two key innovations: (1) strategies that target both clinicians and patients and (2) sequential strategies with increased intensity for non-responders. CONCLUSION: This study aims to determine the effect of different sequences and combinations of implementation strategies on primary care documentation of goals of care conversations. Study partners, including the VA National Center for Ethics in Health Care and Office of Primary Care, can consider policies based on study findings.