Background <p>Patient involvement within academic and for-profit medicines and medical technology research and development is happening across organisations and functions. Frameworks exist to conceptualise involvement activities along a spectrum based on patient contributions and their share of voice and decision-making. Examples range from Informing and Education of patients through to Co-design and Co-Production e.g., in research and development. Varying levels of patient expertise profiles also exist based on a spectrum of experience and expertise – from Patient by Experience through to Patient Key Opinion Leader (KOL) – though researchers often lack clarity on the most relevant skills and knowledge of patient partners suited to the task at hand. Here, we propose a conceptual matrix model combining these two concepts into a simple, pragmatic framework intended for patient involvement professionals in research and development, but with broader relevance for other contexts.</p> Methods <p>As authors with a mix of academic, for-profit industry, and patient advocacy backgrounds, we utilised intellectual exchange and consensus formation in three workshops to develop the model.</p> Results <p>We have developed a conceptual matrix model and applied illustrative case study examples from among our collective experiences and network to demonstrate the model in action. Trends in sample sizes, patient diversity, project longevity, and share of influence exist along the matrix axes. For example, greater numbers and diversity of patients are typically seen at the lower levels of involvement, where there is greater capacity for breadth of involvement.</p> Conclusions <p>Our aim for this model is to support and encourage patient involvement professionals to better determine appropriate levels of involvement and patient expertise needed for their projects and activities, enabling them to facilitate more appropriate, fair, effective, and sustainable patient involvement.</p>