Research on planning, method choice, and method substitution in adolescents' suicide attempts is limited. We conducted in-depth interviews with 20 adolescents following their suicide attempt to learn the extent to which the attempt was planned, why they used the method they did, and whether they would have substituted another method if the one they used had been unavailable. Applied Thematic Analysis was used to identify codes and develop themes. Attempts were largely unplanned, and planned attempts were often haphazard, as urgency to escape immediate pain was a main impetus for the attempt. Method choice was driven by easy access. Half of participants said they would not have attempted suicide if the method they used were inaccessible, but 7 of 20 said they would have, and 3 were unsure. Not all suicide attempts would be prevented by blocking access to methods that adolescent attempters would otherwise use. To understand whether restricting access to low-lethality methods could harm some attempters, future research should examine in-the-moment method substitution.