EMS providers work in a high-stress environment and are routinely exposed to critical incidents. Many providers are left to deal with the chronic stress on their own, either because of lack of effective employer-based programs or a culture that discourages its use. The extent to which these factors -- as well as personal characteristics such as resilience, PTG, and coping skills -- influence PTSD and suicide ideation among EMS providers has not been well studied among EMS providers. An online survey was administered to a convenience sample of EMS providers. Of the 2,683 respondents, more than one quarter (27.7%) met the PTSD criteria of 50 or higher on the PCL-M. Close to half of the respondents (42.0%) reported having contemplated suicide in the last six months. Of those who had contemplated suicide in the last 30 days, nearly one third (27.1%) thought about suicide 10 or more days in the last 30 days. EMS culture and resilience were negatively associated with PTSD, while positive associations were found with some coping styles. PTSD scores and suicide ideation frequency were highest when post-incident services were not available in the workplace. No significant relationships were found between personal factors and suicide ideation.