Response to the commentary "to the bone".

•Presenting process data - even in the absence of outcome data - supports a timely understanding of new, complex programs.•Seminal frameworks guided this research, but our emphasis on moderators was guided by data rather than frameworks.•Complexity here refers to a gap between what seemed feasible (early on) vs.

"I wanted a skeleton … they brought a prince": A qualitative investigation of factors mediating the implementation of a Performance Based Incentive program in Malawi.

While several evaluations have examined the extent to which performance based financing (PBF) programs induce changes in the quantity and quality of health services provided, less is known about the process of implementing PBF. We conducted a process evaluation of a PBF intervention in Malawi that focused on understanding moderators of program implementation. Informed by a seminal theory of implementation, we first created a timeline and taxonomy of key events in the program lifeline and then undertook 25 in-depth interviews with stakeholders including implementers, central-level ministry officials and district-level health staff.