Frontier Insurance Company is a property and casualty insurer domiciled in the State of New York. The company was placed in rehabilitation and the New York Superintendent of Insurance was appointed as Rehabilitator on October 15, 2001, by order of the Supreme Court of the State of New York. Upon the petition of the Superintendent of Financial Services of the State of New York (the successor to the Superintendent of Insurance), the company's rehabilitation proceeding was converted to a liquidation proceeding on November 16, 2012 by order of the Supreme Court of the State of New York.

Frontier wrote commercial auto, workers' compensation, homeowners, general liability and medical malpractice coverage as well as surety bonds.