1990–1991 — President of the Association of Young Journalists "OKO" MGIMO. In 1993 he founded the agency for the development of public relations, "Mikhailov and Partners". In 2004 he was appointed as advisor of the President — a member of the Board of JSCo "Russian Railways". In 2006–2012 years he was head of the Corporate Communications Department. Sergey Mikhaylov reformed the system of internal and external communications of the Russian Railways, made the rebranding of the company. September 17, 2012 was appointed General Director of Federal State Unitary Enterprise "Information Telegraph Agency of Russia (ITAR-TASS)" (in 2014 renamed "The Russian Information Agency "TASS").
Chief Executive Officer, Russian News Agency TASS.