Answer: When entering corporate authors, put a comma after the name:

U.S. Department of Agriculture,
Apple Computer Inc.,

This ensures that the entire name is treated as a first name, so no name manipulation will be applied.

If your corporate author name includes a comma in the name itself, use two commas in place of the first comma:

University of California,, Irvine

EndNote treats this as a last name followed by a blank first name. Then, everything after the (blank) first name is appended, including a second comma in the name. The formatted result is the corporate name with the comma in place.