A surgical stapling instrument that is configured to be used in connection with different sizes of interchangeable end effectors. The end effectors are removably couplable to an elongated shaft assembly that protrudes from a handle assembly. The end effectors are configured to support different sizes of implantable staple cartridges therein. The staples within the staple cartridge are formed as an anvil portion of the end effector is compressed into the staple cartridge. The surgical stapling instrument further includes removable adapters that facilitate attachment of different sizes of end effectors to the elongated shaft assembly.