Testable isolation packer and method for testing an isolation packer in a wellbore casing

Certain aspects are directed to a testable isolation packer that sets and provides the ability to test upper and lower packer elements. In one aspect, the testable isolation packer includes at least two packer elements, a packer element setting system, a bypass system, and a testing subassembly. The testing subassembly generally includes a moveable element with an outer port and a sealing element, an inner mandrel with an inner port, and a shear mechanism to cause travel of the moveable element close the bypass system and to open the testing subassembly.