An energy meter comprising: a meter housing; an energy usage measuring system arranged within the meter housing, the energy usage measuring system including an advanced metering infrastructure, i.e., AMI, module interface member; the meter further comprising: an AMI cartridge operatively connected to the energy usage measuring system, the AMI cartridge comprising: an AMI cartridge housing including a first housing member and a second housing member that collectively define an interior zone; and an AMI module system supported within the interior zone of the AMI cartridge, the AMI module system including an AMI module and an adapter interface including a printed circuit board having an energy meter interface that is provided with an energy meter connector, the energy meter interface being covered by an energy meter interface member on first housing member, the AMI module system including at least one communication port (95, 97, 99, 100) configured and disposed to communicate with a remote system and including one of an RS-232 port, a sub-miniature version D port, an RJ45 port, and a sub-miniature version A port, wherein the meter housing is provided with an AMI cartridge receiving portion comprising first and second tab elements (31, 32) and a pair of side walls, wherein said first and second tab elements (31, 32) are placed on top of said pair of side walls; and the first housing member further includes a pair of slot elements (53, 54) on opposite sides of the housing that are configured to snap-fittingly engage with said tab elements (31, 32). a meter housing; an energy usage measuring system arranged within the meter housing, the energy usage measuring system including an advanced metering infrastructure, i.e., AMI, module interface member; the meter further comprising: an AMI cartridge operatively connected to the energy usage measuring system, the AMI cartridge comprising: an AMI cartridge housing including a first housing member and a second housing member that collectively define an interior zone; and an AMI module system supported within the interior zone of the AMI cartridge, the AMI module system including an AMI module and an adapter interface including a printed circuit board having an energy meter interface that is provided with an energy meter connector, the energy meter interface being covered by an energy meter interface member on first housing member, the AMI module system including at least one communication port (95, 97, 99, 100) configured and disposed to communicate with a remote system and including one of an RS-232 port, a sub-miniature version D port, an RJ45 port, and a sub-miniature version A port, wherein the meter housing is provided with an AMI cartridge receiving portion comprising first and second tab elements (31, 32) and a pair of side walls, wherein said first and second tab elements (31, 32) are placed on top of said pair of side walls; and the first housing member further includes a pair of slot elements (53, 54) on opposite sides of the housing that are configured to snap-fittingly engage with said tab elements (31, 32). an AMI cartridge operatively connected to the energy usage measuring system, the AMI cartridge comprising: an AMI cartridge housing including a first housing member and a second housing member that collectively define an interior zone; and an AMI module system supported within the interior zone of the AMI cartridge, the AMI module system including an AMI module and an adapter interface including a printed circuit board having an energy meter interface that is provided with an energy meter connector, the energy meter interface being covered by an energy meter interface member on first housing member, an AMI cartridge housing including a first housing member and a second housing member that collectively define an interior zone; and an AMI module system supported within the interior zone of the AMI cartridge, the AMI module system including an AMI module and an adapter interface including a printed circuit board having an energy meter interface that is provided with an energy meter connector, the energy meter interface being covered by an energy meter interface member on first housing member, the AMI module system including at least one communication port (95, 97, 99, 100) configured and disposed to communicate with a remote system and including one of an RS-232 port, a sub-miniature version D port, an RJ45 port, and a sub-miniature version A port, wherein the meter housing is provided with an AMI cartridge receiving portion comprising first and second tab elements (31, 32) and a pair of side walls, wherein said first and second tab elements (31, 32) are placed on top of said pair of side walls; and the first housing member further includes a pair of slot elements (53, 54) on opposite sides of the housing that are configured to snap-fittingly engage with said tab elements (31, 32).