Hildebrandt now became a key SPD figure in the state politics of Brandenburg. In October 1990, the state tier of government was reintroduced to what had been the German Democratic Republic, and as part of the process elections took place for a new state parliament in Brandenburg on 26 October. Hildebrandt was elected as an SPD member and then appointed to ministerial office under minister-president Manfred Stolpe: from 1 November 1990 onwards she served as Brandenburg's Minister for Labour, Social affairs, Health and Women, in effect an expanded version of the ministerial portfolio she had been handling nationally earlier in the year.