General information Provider portal https://www.coresource.com/how-can-we-help-you/providers Phone (844) 274-5819 Website http://www.mycoresource.com Precertification Phone (800) 480-6658 Website http://www.mycoresource.com Claims Phone (800) 999-0114 Mailing address PO Box 2310 Mt Clemmens, MI 48046 United States Additional information Payer Number NGS01 EDI payer # 38225