Each insurer licensed to write motor vehicle insurance in this Commonwealth shall institute and maintain a motor vehicle insurance antifraud plan. The antifraud plan of insurers licensed on the effective date of this subchapter shall be filed with the department on or before December 31, 1990. All insurers licensed after the effective date of this chapter shall file within six months of licensure. All changes to the antifraud plan shall be filed with the department within 30 days after it has been modified.