Nripendra Misra and PK Mishra were re-appointed as Principal Secretary and Additional Principal Secretary, respectively on Tuesday.
The Appointments Committee of the Cabinet has approved both the appointments with effect from May 31, according to orders issued by the Personnel Ministry.
During the term of their office, they will be assigned as the rank of Cabinet minister.
Nripendra Misra was appointed the Principal Secretary to Modi on May 28, 2014. He is a 1967-batch retired IAS officer of Uttar Pradesh cadre.
Nripendra Misra, who has served in various capacities in the government, retired as the chairman of the Telecom Regulatory Authority of India (TRAI) in 2009.
Principal Secretary Mishra, a 1972-batch retired IAS officer of Gujarat cadre, served in the same position in the last five years of the Modi government.
PK Mishra had served between 2001 and 2004 as the Principal Secretary to Modi when he was the Gujarat chief minister.
PK Mishra was the Secretary in the Ministry of Agriculture between December 1, 2006 and August 31, 2008.
After his retirement, he was appointed the chairman of the Gujarat Electricity Regulatory Commission for a five-year-term.
Mishra, considered close to Modi, has held various key positions at the Centre and in the Gujarat government.
The Appointments Committee of the Cabinet has earlier approved re-appointment of Ajit Doval as the National Security Adviser in the rank of Cabinet minister.