The Fortune 500 gained 291 new entrants after Fortune changed its methodology in 1994 to include service companies.
Before the change, the ranking focused mainly on businesses whose revenue came from manufacturing, mining, and energy exploration. Fortune published separate industry lists for sectors such as commercial banking, utilities, insurance, retail, and transportation, so the main 500 did not represent the entire U.S. economy.
The 1994 revision folded service businesses into the central ranking. That produced a major reshuffling and brought 291 companies onto the list, including three that entered the top ten. The change reflected the growing importance of finance, communications, health care, technology, and other service industries.
A common mix-up is to confuse these 291 entrants with the fixed size of the list itself. The Fortune 500 remained a 500-company ranking; 291 companies were new to the expanded methodology, replacing companies that no longer qualified or fell outside the cutoff.