War-related medical costs for U.S. veterans of Iraq and Afghanistan may be enormous because of differences between these wars and previous conflicts: (1) Many veterans survive injuries that would have killed them in past wars, and (2) improvised explosive device attacks have caused "polytraumatic" injuries (multiple amputations; brain injury; severe facial trauma or blindness) that require decades of costly rehabilitation. In 2035, today's veterans will be middle-aged, with health issues like those seen in aging Vietnam veterans, complicated by comorbidities of posttraumatic stress disorder, traumatic brain injury, and polytrauma. This article cites emerging knowledge about best practices that have demonstrated cost-effectiveness in mitigating the medical costs of war. We propose that clinicians employ early interventions (trauma care, physical therapy, early post-traumatic stress disorder diagnosis) and preventive health programs (smoking cessation, alcohol-abuse counseling, weight control, stress reduction) to treat primary medical conditions now so that we can avoid treating costly secondary and tertiary complications in 2035. (We should help an amputee reduce his cholesterol and maintain his weight at age 30, rather than treating his heart disease or diabetes at age 50.) Appropriate early interventions for primary illness should preserve veterans' functional status, ensure quality clinical care, and reduce the potentially enormous cost burden of their future health care.