In 1937, in the time of the Third Reich, unlike its two neighbouring municipalities, Schmidthachenbach was grouped into the Birkenfeld district. In 1950, Schmidthachenbach had 498 inhabitants, and this year also marked the end of winegrowing in the municipality. In 1957, "Flurbereinigung" began. In 1958, a memorial was built and dedicated to those who fell or went missing in the First World War and the Second World War. In the course of administrative restructuring in Rhineland-Palatinate, the "Amt" of Weierbach was dissolved and Schmidthachenbach was grouped into the "Verbandsgemeinde" of Herrstein.