An LED lighting system, lamp retrofit system, kit, and method is presently disclosed. The LED retrofit system comprises at least one longitudinally extending LED lamp having a length substantially greater than a width and open longitudinal ends. A first LED lamp support rail holds and covers a first open longitudinal end of each of the at least one longitudinally extending LED lamps and is configured to electrically connect each of the at least one longitudinally extending LED lamps to a power source. A second LED lamp support rail holds and covers a second open longitudinal end of each of the at least one longitudinally extending LED lamps held with the first LED lamp support rail. A system holder on each of the first and second LED lamp support rails is configured and disposed to hold the retrofit system to a portion of a lamp fixture being retrofitted.