Hilgenfeldt worked as office head at the NSDAP Office for People's Welfare and in close association with the "Nationalsozialistische Volkswohlfahrt" (NSV), or the National Socialist People's Welfare. By organizing a charity drive to celebrate Hitler's Birthday on 20 April 1931, Joseph Goebbels named him the head of the NSV. The NSV was named the single Nazi Party welfare organ in May 1933. On 21 September 1933 he was appointed as Reich Commissioner for the "Winterhilfswerk" (Winter Support Programme). Under Hilgenfeldt the programme was massively expanded, so that the régime deemed it worthy to be called the "greatest social institution in the world." One method of expansion was to absorb, or in NSDAP parlance coordinate, already existing but non-Nazi charity organizations. NSV was the second largest Nazi group organization by 1939, second only to the German Labor Front.