Many Veterans Affairs (VA) patients with the complications of cardiometabolic syndrome (CMS) use both VA and community providers and facilities outside of VA. Although dual health care systems increase care options, dual use also increases coordination needs. The fragmentation and duplication of health care due to the use of multiple facilities and providers may hinder effective care coordination, result in less efficient and more costly care, and lead to poorer outcomes. This article, which is based upon bibliographic searches in PubMed, reviews the evidence on dual use of VA and community health care by Veterans for acute myocardial infarction (AMI), congestive heart failure (CHF), and diabetes mellitus, the most common CMS complications requiring acute care and post-acute care services. A total of 179 articles were identified. After screening the full texts or abstracts of the 179 articles, 11 studies met the criteria, including two qualitative studies and 9 quantitative using administrative and Medicare records for veterans with AMI, CHF, or diabetes. Among the analytic studies, 3 had a cross-sectional design and 6 were cohort studies. The results of studies completed to date suggest that dual healthcare system use by older male veterans with cardiometabolic conditions is not associated with improved outcomes and may lead to unnecessary tests or procedures and increased healthcare costs. Additional research is warranted to examine the prevalence of dual health care system use by male and female veterans during recent time periods and to compare outcomes among patients who receive only VA care, only community care, or both VA and community care.