Meghalaya Chief Minister Mukul Sangma
Reshuffle was done ahead of the assembly session, which would begin on September 9.
Governor V. Shanmuganathan administered the oath of office and secrecy to Martin M. Danggo and Ronnie V. Lyngdoh in the Raj Bhavan in Shillong.
Deputy Chief Minister in-charge Law Rowell Lyngdoh and Health and Family Welfare Minister Alexander Hek resigned on Thursday from the cabinet after directives from Congress president Sonia Gandhi.
Earlier, Sonia Gandhi had deputed Congress leader Mukul Wasnik and Congress General Secretary in-charge C.P. Joshi to prevent a possible split in the state Congress before the 2018 assembly elections.
She approved the removal of Hek for his "political hobnobbing" with the Bharatiya Janata Party and that of Lyngdoh mainly on account of his old age, said reports.
Hek had twice won elections on BJP ticket before joining the Congress.
Meghalaya has a 12-member ministry, including the chief minister.