In the United States, although there is no federal or state licensing or certification for translators, there are federal and state licensing and certification for interpreters.  While translation normally refers to written translation, interpretation refers to oral interpretation.

 In California, for example, certain documents are required to be translated by court certified interpreters.  As of July 26, 2007, there are 23 court certified Mandarin interpreters in California. 

The American Translators Association offers translator certification for English to Chinese translations.  Currently, there are a few dozen of American Translators Association certified English to Chinese translators in the United States.