United States federal executive departments

The heads of departments are members of the Cabinet of the United States, an executive organ that normally acts as an advisory body to the president.

To enforce a strong separation of powers, the federal Constitution's Ineligibility Clause expressly prohibits executive branch employees (including heads of executive departments) from simultaneously serving in Congress, and vice versa.

Accordingly, in sharp contrast to parliamentary systems where ministers are often selected to form a government from members of parliament,[1] U.S. legislators who are appointed by the president and confirmed by the Senate to serve as heads of executive departments must resign from Congress before assuming their new positions.

[3] As is evident from the chart below, several executive departments (Education, Health and Human Services, Housing and Urban Development, and Transportation) have disproportionately small employee headcounts in contrast to the size of their budgets.

In the 20th century, when the federal government began to provide funding and supervision for matters which were historically seen as the domain of state governments (i.e., education, health and welfare services, housing, and transportation), Congress frequently authorized only funding for grants which were voluntary, in the sense that state or local government agencies could choose to apply for such grants (and accept conditions attached by Congress) or they could decline to apply.