The agreement with Germany became effective on December 1, 1979. A supplementary agreement, which became effective on January 1, 1986, did not affect the coverage provisions of the original 1979 agreement. A second supplementary agreement, which did modify the coverage provisions of the original agreement, became effective on May 1, 1996.

Workers whose employment or self-employment would otherwise be covered by both the U.S. and German Social Security systems are covered and taxed by only one country's system beginning December 1, 1979. The agreement does not affect a worker's coverage prior to that date. If a worker had earnings before December 1, 1979 that were dually covered, those earnings would be subject to Social Security taxes in both countries.