Studies have been conducted regarding suicide rates among military members/Veterans who deployed in the Afghanistan/Iraq conflicts [1], [2], however, there has been less work on accidental death risk (e.g., motor vehicle accident [MVA] or accidental overdose deaths) [3], [4]. Yet, studies have shown that accidental death is the most common type of mortality during- and post-service among those who served in Afghanistan/Iraq [4], [5], [6]. We do not know if accidental death risk varies in the years following deployment; information that is critical to prevention and intervention planning following combat deployments.

Accidental death research among military members/Veterans from the Afghanistan/Iraq cohort has focused on accidental deaths overall, or on one type [7], [8], [9], [10], [11]. The Department of Defense’s (DoD) Armed Forces Health Surveillance Division reported that transportation deaths (e.g., MVA) were the most common type (over 30 % annually) of non-war related death during the first decade of the conflicts [5]. Another study found that among Veterans discharged from military service in 2001–2007, MVA mortality risk was highest in the first 3 years following military discharge [12]. Moreover, Veterans are at disproportionately higher risk for accidental overdose deaths compared to the general population. [13], [14].

We examined a cohort of 860,930 soldiers returning from an Afghanistan/Iraq deployment between fiscal years (FYs) 2008–2014. Study objectives were to: 1) estimate average annual accidental death mortality rates (all, MVA, overdose) by demographic and military characteristics and compare rates across groups; and 2) estimate postdeployment time-dependent hazard rates and trends for accidental death, and compare trends across groups.