Studied economics and quantitative methods and information systems at Warsaw School of Economics. In 2003 he obtained a PhD in economics from the Institute of Economics of the Polish Academy of Science (PAN).
He started his professional career in the Ministry of Finance, he later worked at the Supreme Chamber of Control, the Ministry of Justice and the Social Insurance Fund. On November 23, 2003 he became a Director General of the Ministry of Finance.
Adam Niedzielski combined work for the public administration with the research work at the Institute for Market Research (1998-2004) and at the Higher School of Trade and International Finance (1999-2007). He was a member of supervisory board of the social purpose company - Critical Application (2017-2018). From January to July 2018, by the decision of Minister of Finance, he became a member of National Health Fund Council.
Since July 12, 2018 he was a vice-executive director of National Health Fund responsible for operational matters. On July 18, 2019 he became an acting executive director of National Health Fund and on October 10, 2019 he was appointed by the Minister of Health as the executive director of the Fund.
He is an expert in public management. Author of publications and books in public administration, public finance and management control.
On August 20, 2020 Adam Niedzielski was appointed the Minister of Health of Poland, by the Prime Minister, Mateusz Morawiecki.
On August 26 was sworn in by the President of the Republic of Poland, Andrzej Duda.