South African Els, who won the year's second major in 1994 and 1997, gained a spot by virtue of being ranked in the top 60 on May 21. Els, a former world number one, is ranked 44th.
The smooth-swinging Els failed to qualify for this year's Masters after dropping out of the top 50 in the world rankings, the first time he had not competed at Augusta National since his debut there in 1994.
Others gaining full exemptions for the June 14-17 US Open at The Olympic Club in San Francisco include Britain's Paul Casey, Simon Dyson and Ian Poulter, Dane Thomas Bjorn, Spaniards Gonzalo Fernandez-Castano, Miguel Angel Jimenez and Alvaro Quiros, and Swedes Robert Karlsson and Carl Pettersson.
Also qualifying via the world rankings are Japan's Ryo Ishikawa, Americans Ben Crane, Rickie Fowler and Zach Johnson, and Belgian Nicolas Colsaerts, who won the European Tour's World Match Play Championship in Spain on Sunday.
Further spots in the US Open field will be earned via the world rankings on June 11, and also through 36 holes of sectional qualifying which will take place in Surrey, England, on May 28 and at 11 venues in the United States on June 4.