Subramanian, a Senior Fellow at the Peterson Institute for International Economics, was appointed India's Chief Economic Adviser (CEA) in October 2014. His term was for three years, which was to end on October 16.
Interacting with reporters today, Jaitley said Subramanian will get one year extension.
The BJP-led NDA government's 5-year term ends in May 2019.
The CEA is usually the main go-to person for advice for the finance minister on macro-economic matters, and primary responsibilities, among others, include authoring the mid-year analysis and the Economic Survey.
Subramanian graduated from St Stephen's College, Delhi, and got an MBA from the Indian Institute of Management, Ahmedabad. He obtained M.Phil and D.Phil from the University of Oxford, UK.