Severe maternal morbidity and mortality continue to increase in the United States, largely owing to chronic and newly diagnosed medical comorbidities. Interconception care, or care and management of medical conditions between pregnancies, can improve chronic disease control before, during, and after pregnancy. It is a crucial and time-sensitive intervention that can decrease maternal morbidity and mortality and improve overall health. Despite these potential benefits, interconception care has not been well implemented by the primary care community. Furthermore, there is a lack of guidelines for optimizing preconception chronic disease, risk stratifying postpartum chronic diseases, and recommending general collaborative management principles for reproductive-age patients in the period between pregnancies. As a result, many primary care providers, especially those without obstetric training, are unclear about their specific role in interconception care and may be unsure of effective methods for collaborating with obstetric care providers. In particular, internal medicine physicians, the largest group of primary care physicians, may lack sufficient clinical exposure to medical conditions in the obstetric population during their residency training and may feel uncomfortable in caring for these patients in their subsequent practice. The objective of this article is to review concepts around interconception care, focusing specifically on preconception care for patients with chronic medical conditions (eg, chronic hypertension, chronic diabetes mellitus, chronic kidney disease, venous thromboembolism, and obesity) and postpartum care for those with medically complicated pregnancies (eg, hypertensive disorders of pregnancy, gestational diabetes mellitus, excessive gestational weight gain, peripartum cardiomyopathy, and peripartum mood disorders). We also provide a pragmatic checklist for preconception and postpartum management.