In the literature, this topic was addressed mainly through head to head cost effectiveness studies; a budget impact analysis taking the INHS point of view was lacking. The only such analysis in the literature is a 2014 study by Angeletti et al,22 whose objective, however, was the assessment of different cost saving strategies. Among these, the switch of 20%–40% of stable first and second line patients from PI-based triple therapies to PI-based monotherapies was estimated to lead to yearly savings for the Health Service of the Lazio region of between 1.0 million € and 1.9 million €, considering the total cost for the Regional Health Service to provide care to patients (considering antiretroviral drugs, nonantiretroviral drugs, hospital admissions, out-patient care, and laboratory tests). These amounts represent 0.6% and 1.3%, respectively, of the yearly regional cost of care of HIV-positive patients