Planning by the Numbers Free
A Simulation Model for Mental Health Systems - Version 1.0

Planning by the Numbers Free


Video guided tour of PBN Free from Steve Leff’s APHA Carl A. Taube Award Lecture
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The Planning by the Numbers simulation model for mental health planning (PBN) was initially developed over 30 years ago and has been further developed and maintained by Steve Leff, Ph.D. (lead developer of this web site) and colleagues. Over this period the model has been used in a number of states and counties for purposes such as budget planning and justification, negotiating law suits and research and evaluation. A bibliography of resources concerning the model is available in the Resources section.

Over time data for the model has been obtained from administrative data sets, specially designed surveys and expert panels. In all cases we included and recommend including in the modeling process mental health consumers, providers, advocates, policy makers, planners and evaluators.

This free version of PBN (PBN Free) is presented to the mental health community in hopes that it will be useful in system resource allocation, planning, evaluation and research. The web site pages take users through the main steps in developing a model, running the model and exploring model results. The Full Version of PBN (PBN Full) is available for purchase in the context of consultations with the HSRI modeling team. To inquire about consultations please contact Steve Leff at

There is also a blog associated with PBN Free that addresses PBN Free and other mental health planning related topics. It can be accessed at: