I. ˌOffice of ˌManagement and ˈBudget, the BrE AmE abbreviation , OMB
a US government organization that provides help for the President in organizing the work of government departments and especially in preparing the ↑ budget (=the official plan for how government money will be used)
II. OMB, the /ˌəʊ em ˈbiː $ ˌoʊ-/ BrE AmE
the abbreviation of the ↑ Office of Management and Budget