NEW YORK ( TheStreet) -- Cerner ( CERN) will replace BJ Services ( BJS) in the S&P 500 index, Standard & Poor's said Thursday. Shares of Cerner, a healthcare information technology company, rose $2.46, or 2.81%, to $89.90 in after-hours trading. BJ Services is being acquired by Baker Hughes ( BHI). The changes to the index will be made at a date to be announced, Standard & Poor's said. -- Reported by Joseph Woelfel in New York. Follow TheStreet.com on Twitter and become a fan on Facebook.