After stepping down from chairman of SSU, Ringholm worked as a political adviser at the Ministries of the Interior and Labour. He also became active in the local politics of Stockholm. From 1973 he was a member of the Stockholm County Council, and two years later he was elected to the executive committee of the Stockholm party branch. In 1976 he became a director at the Ministry of Education and Science, and worked in the government administration until he became Transportation Commissioner of the Stockholm County from 1983. From 1997 he was the director-general of the Swedish Labour Market Board (AMS), until Prime Minister Göran Persson unexpectedly named him to succeed Erik Åsbrink as Minister for Finance in 1999.