ADP, LLC., is an American provider of business outsourcing solutions. It was also a provider of computing services to automobile and heavy equipment dealers, but spun off those businesses in 2014. ADP was formerly one of four American companies to get a AAA credit rating from Standard & Poor's (S&P) and Moody's, but S&P and Moody's downgraded ADP to AA in April 2014, after the dealer services unit spin off.