Before signing a contract verify contractor's license with Maryland Home Improvement Commission (MHIC) to make sure the license is still active. You may verify online or by phone:
toll free: 1-888-218-5925
Baltimore area: 410-230-6231
Address: 1100 North Eutaw Street, Baltimore, MD 21201
Any home improvement contractor should provide you with current general liability insurance certificate. In order to be working at your home the contrator must have a copy of a current worker's compensation insurance certificate.