NATICK , Mass . , March 12 / PRNewswire-FirstCall / -- Boston Scientific Corporation ( NYSE : BSX ) today announced that Moody 's Investors Service has raised the Company 's rating outlook to stable from negative . In addition , Moody 's upgraded the Company 's U.S. public bond rating to Ba1 from Ba2 and its liquidity rating to SGL-2 from SGL-3 , while affirming its corporate credit rating at Ba1 .