On 1 August 1929, Hilgenfeldt became an NSDAP member (no. 143642), and by 1932 he had become NSDAP Kreisleiter (District Leader) and by 1933 NSDAP Gauinspektor for Inspektion I Groß-Berlin.[citation needed] By 1931 he was a municipal councillor for Berlin-Welmersdorf.[4]