Health Management Information Systems (HMIS) have been used by many countries using platforms adopted or own-designed. It’s implemented by integrating all healthcare services and gives service providers the ability to collect, store and use health data. The System is able to provide information on all aspects of the organization from billing to patient care and beyond. Despite its significance, lack of specificity and clarity hamper systematic understanding, successful implementation, and evaluation of its functional factors. The study is aimed at assessing the functional factors for Health Management Information System (HMIS) performance in Elgeiyo-Marakwet County (EMC). The specific objective to: determine technical factors for HMIS performance in the County. Quantitative research method was used and data gathered through administration of questionnaires to 52 respondents across the county. Data was analyzed using Statistical Package for the Social Sciences (SPSS) computer software version 20.0. The study found that there is presence of technical factors which includepresence of standard indicators, manuals, reporting forms and time, data presentation & analysis for HMIS. The study concludes that competency in HMIS tasksand availability of minimum package of information (MPI) for collection, collation, analysis, dissemination and use of health information in HMIS. The study recommends enhanced support for technical inputs for greater performance for HMIS and regular review in the county