Research has consistently linked marriage and positive health outcomes. In addition, many researchers have found that couples often have similar or concordant health statuses. However, concordance research has been conducted in many fields for decades without a concise review of the literature, nor has one theory of health concordance been established. A systematic review was performed implementing rigorous identification strategies, and 103 health concordance research articles were identified and reviewed to understand what research has been conducted in mental health, physical health, and health behavior concordance among couples. The research overwhelmingly suggests evidence for concordant mental and physical health, as well as health behaviors among couples. Each area of health concordance research offers room for greater research and deeper understanding for the causes of health concordance.