His early post-Soviet assignments included advising the newly independent governments of Kazakhstan and Kyrgyzstan on monetary stabilization, central banking, fiscal policy, and the institutions needed to support market economies. He later helped establish Kyrgyzstan's first oil refinery through financing raised on the Toronto Stock Exchange.
His career increasingly focused on post-conflict reconstruction. From 1999 to 2002, Lewarne led the U.S. government's Kosovo Economic Reconstruction Program and served as minister of reconstruction under the United Nations administration, helping design Kosovo's first reconstruction budget and establish key fiscal and monetary institutions. He later served as a senior economic adviser in Afghanistan, Iraq, South Sudan, Ukraine, and other post-conflict states, advising governments and central banks on monetary policy, fiscal institutions, trade, and economic stabilization.
Lewarne also helped grow an international development firm prior to its acquisition by AECOM, where he became executive vice president and led its economic growth practice. He later spent 14 years as a senior partner at Deloitte Consulting, overseeing international applied economics and public financial management programs valued at more than $500 million.
In 2024, he returned to federal service as a senior fiscal economist and adviser at the U.S. Department of State, providing fiscal and public finance guidance to USAID missions and senior U.S. officials. He now serves as professor of economics and finance at Franciscan University of Steubenville.
His publications include Economic Governance in War-Torn Economies: Lessons Learned from the Marshall Plan to the Reconstruction of Iraq and other works on monetary policy, financial markets, and technological change.
Lewarne and his wife, Beth, have four children, including triplets.
