Emergency Medical Services Corp., an ambulance operator and medical staffing contractor, received a subpoena from the U.S. Justice Department in December asking for documents from January 2000 to the present, the company said in a regulatory filing.

The company, based in Greenwood Village, said in a 10K filing today with the Securities and Exchange Commission the subpoena is related to some of its American Medical Response Inc. affiliates in New York. The company said it is producing

the documents.

Its stock fell 74 cents, or 2.9 percent, to $24.86 at 9:58 a.m. New York time in New York Stock Exchange composite trading.

Deborah Hileman, EMS’s vice president of corporate communications and investor relations, didn’t immediately return voice-mail and e-mail messages.