Norawich Lalaeng and Bancha Parameesanaporn met the NACC at its temporary office at the Nonthaburi Municipality with an assignment letter from the prime minister.
The letter authorised the lawyers to acknowledge the NACC's charges on Ms Yingluck's behalf, to testify or submit a statement and evidence in her defence, and to request copies of case investigation reports for examination.
Caretaker Prime Minister Yingluck Shinawatra is accused of knowing about corruption in the rice-pledging scheme and failing to stop it.
The anti-graft agency said she ignored warnings that the rice scheme was fostering corruption and causing financial losses. She has been charged with dereliction of duty, which could lead to a five-year ban from politics.
Ms Yingluck assigned her legal team to answer the charges at an NACC hearing, as she completed the second day of an official trip to the North.