Smart Metering systems, in addition to the function of energy consumption metering, can support a wide variety of additional features using optional devices or programming. These functionalities foster the implementation of key elements of Smart Grids (SG) such as distributed generation, new market models, advanced tariff schemes, among others. The Colombian's Smart Grid Roadmap identifies the implementation of smart metering through an Advanced Metering Infrastructure (AMI) as one of the first activities to be carried out to implement the SG in Colombia. This activity must be carefully planned to gradually activate all AMI functionalities required by the regulation and the market in a period of time without the need to change the meters; this will ensure a good return of investment of the adoption of this technology throughout its useful life. This paper presents the agreed methodology for the process of defining the minimal functionality required for AMI in Colombia and the expected benefits for the Colombian electric sector.