A computer implemented method for providing code list extensibility includes providing a first code data type representation. The first code data type representation corresponding to a first code data type and having a first code value representation for at least one code value. The at least one code value associated with a corresponding code value issuing entity. The method may also include providing a second code data type representation. The second code data type representation corresponding to the first code data type and having a second code value representation for the at least one code value. The second code value representation including a unique identifier associated with the code value issuing entity. The method also may include mapping the first code data type representation and the second code data type representation based at least in part on the unique identifier associated with the code value issuing entity.