In his new role, Corbett is responsible for MassMutual's overall investment strategy, as well as oversight of the company's General Investment Account. He reports to Roger Crandall, chairman, president and CEO of MassMutual. He began his professional career at Aetna in 1982, where over a 20-year career he held a number of investment positions with increasing responsibility, ultimately becoming head of portfolio management.

From 2002 to 2008, he was head of asset management at the Hartford Investment Management Company.

MassMutual provides products such as life insurance, disability income insurance, long term care insurance, retirement/401 plan services, and annuities. In addition, the company provides financial advice. The firm was founded in 1851. Its major affiliates include: Babson Capital Management; Baring Asset Management; Cornerstone Real Estate Advisers and The First Mercantile Trust Company.