But the prime minister has been caught up in a dispute with the leader of the party, Hafedh Caid Essebsi, who is also the president's son and has accused Chahed of failing to tackle high inflation, unemployment and other problems.
The political wrangling has alarmed donors which have kept the country afloat with loans granted in exchange for a promise of reforms such as cutting a bloated public service.
Tunisia's economy has been in crisis since the North African state kicked off the Muslim World's "Arab Spring" uprisings by toppling autocrat Zine El-Abidine Ben Ali in 2011.
Chahed's reshuffle announced on Monday is the 10th major cabinet overhaul since then.
He said it would "make the work of government more effective and to put an end to the political and economic crisis".
Chahed kept the leadership of finance, foreign and the interior ministries unchanged.
He named Jewish businessman Rene Trabelsi as minister of tourism in the Muslim Arab country, just the third member of the small minority to enter the cabinet since Tunisia's independence in 1956.
A former foreign minister under Ben Ali, Kamel Morjan, was named minister in charge of the public service, the country's main employer.