Sung Ah Yim turned pro in late 2002. She played on the KLPGA tour in 2003, where her results were decent but unspectacular. In 2004, she moved to America and played on the Futures Tour, where she did better. There, she notched 8 top tens, and managed two more top fives on the KLPGA. At 2004 Q-School, she finished tied for 10th to secure an exempt card for the 2005 season. 2005 has been a strong year for Yim. She notched several top twenties early, then put herself into a position to win at the Jamie Farr Classic. Indeed, had she made a fifteen foot putt for birdie on the final hole, she would have won. As it was, though, she missed that putt and a follow up par, and finished tied for third. A few months later, she took a share of the first round lead at the Safeway Classic and finished tied for 5th. She also notched a 9th at the State Farm Classic after that. Thus, Yim easily retained her exempt status for 2006. Sung Ah had a solid start to her year, contending at the very first event in February. But it was at the Florida's Natural Championship that she made the biggest splash. She played in the final group Sunday with none other than Annika Sorenstam. On paper, it looked like a mismatch, but Yim played well, and in the end it was Annika who blinked first when she hit her tee shot out of bounds on the second to last hole. Thus, amazingly, Sung Ah Yim won her first LPGA event. Shortly thereafter, she got her first top ten in a Major at the LPGA Championship. She wound up 31st on the money list, earning two more years of exemption on tour in the process. 2007 was an off year. She finished out of the top 90 on the money list, but fortunately still had an exempt card thanks to her 2006 win. Yim continued to struggle in 2008; by the end of the season, she had not even managed a top 30 finish on tour all year. Fortunately, she still maintained good status for 2009 thanks to her previous victory. However, after a poor 2009 where she made only 11 thousand dollars, Sung Ah's status for 2010 was reduced to category 15.