Given the finite resources allocated to suicide prevention, it is necessary to direct resources into interventions that are most likely to have an impact. This article tests for possible impacts on youth suicides of a cost-intensive Australian policy change (increased firearms restriction) that limited access to a means of suicide. Suicide rates by different age groups and methods were examined for structural breaks, using Zivot-Andrews and Quandt tests. No breakpoint was found in firearm suicide among Australian youth around the time of the 1996 legislative changes. Method restriction in the form of firearms legislation could not be tied to a corresponding impact on youth suicide.