Traditionally, domestic resource mobilization focuses on the government as the primary stakeholder responsible for raising and managing funds for health, often through taxes. Given the uncertainty around future donor commitments, sustainability concerns, emphasis on countries’ self-reliance, and increasing demand and costs for health care, there is growing interest to look beyond the public sector for additional revenues to fund health. Within this context, stakeholders agree that the private sector is an important source of additional resources that can fill global health funding gaps and help reach targets such as the Sustainable Development Goals. However, there is no consensus on what private sector domestic resource mobilization actually looks like, or its realistic potential. This primer considers a definition and examples, and examines ways to mobilize local private sector resources for health with a focus on family planning. The primer provides lessons learned and recommendations for donors who want to support future efforts in private sector domestic resource mobilization for health.