The majority of female homicide victims are killed by intimate partners. A subset of intimate partner homicide is murder-suicide, where the perpetrator commits suicide after killing their partner. There is a gap in the understanding of the risk factors and situational context surrounding these events. The purpose of this research is to better elucidate intimate partner homicide-suicide across the age-span. Using data from the National Violent Death Reporting System (NVDRS), a multivariable regression analysis will highlight the associations between mental health and substance use and individuals who commit intimate partner homicide-suicide. Perpetrators are categorized as having a mental health issue if any of the binary variables for current mental health problem, current mental health diagnosis, or current mental health treatment at the time of the incident are selected. Perpetrators are categorized as having a substance use disorder if alcohol problem, other substance problem, or other addiction are indicated. Lastly, perpetrators are categorized as having substance use at the time of the incident if toxicology tests are positive for alcohol, amphetamines, cocaine, opioids, or marijuana. Models will also include demographic data on both the victim and perpetrator, the perpetrator-victim relationship status, incident type characteristics, and the mental and behavioral health status of the perpetrator. Additionally, the analysis will be stratified by age group to examine the differences in patterns across the age-span. Results will be used to inform future research, practice, and policy to reduce perpetration and prevent these violent deaths.