This article introduces a model for evaluating the development of Technology Transfer Offices (TTOs), grounded in the balance between intellectual property protection and technology transfer. The model is applied to a phase transition taking place in Brazil, where, in accordance to the Technological Innovation Law of 2004, every Brazilian Science and Technology Centre must establish a TTO, responsible for the management of innovation processes in the institution. The model is presented through the analysis of data from twenty-nine TTOs, aiming at: 1) comparing globally the stage of development of twenty-six TTOs from the ecosystem of the State of Minas Gerais, Brazil; 2) analyzing comparatively the historical evolution of four TTO (two from Brazil, one from the USA and one from Germany). The model introduced is not limited to TTO evaluation; it can be applied to study the development of innovation intermediaries in general. [ABSTRACT FROM AUTHOR]