The delay is to make more background checks into the tax affairs of the future ministers, according to an Elysee statement.
The Elysee Palace said Macron and his new prime minister, Edouard Philippe, decided to delay the cabinet announcement until 3.00 p.m. local time (1300GMT) on Wednesday, to allow a watchdog to carry out background checks on ministers.
According to the statement, members of the government will also sign an "integrity and morality" pledge.
"They will undertake to exercise their governmental functions in an irreproachable way," the statement added.
During his campaign, Macron vowed to fight corruption amid politicians and one of the government's priorities is to pass a draft law on the "moralization of political and public life" before crucial legislative elections next month.
The draft law, suggested and wanted by Macron's ally, leader of the Democratic Movement Party, Francois Bayrou, includes "the prohibition of nepotism for parliamentarians", especially after a fictitious jobs scandal hurt the candidacy of conservative presidential hopeful Francois Fillon.
Under the law, elected members and ministers will be banned from hiring a family member.
A first ministerial cabinet meeting is due to be held on Thursday.