Maryland Code, Business Regulation § 9A-402

(a) A holder of a master, master restricted, or limited heating, ventilation, air-conditioning, and refrigeration license may not contract to provide services on behalf of the licensee, or another person who provides heating, ventilation, air-conditioning, or refrigeration services, unless the work of the licensee, including completed operations, is covered by:

(e) Unless an applicant meets the insurance requirements of this section, the Board may not renew any license of the applicant to whom the insurance requirements of this section apply.

(f) A holder of a master, master restricted, or limited license shall give the Board notice of the cancellation of insurance at least 10 days before the effective date of the cancellation.

(g) If a county, municipal corporation, special taxing district, or other political subdivision requires a master, master restricted, or limited heating, ventilation, air-conditioning, and refrigeration license holder, or other person who engages in the business of providing heating, ventilation, air-conditioning, and refrigeration services, to execute a surety bond under local heating, ventilation, air-conditioning, and refrigeration requirements, the person may satisfy the bond requirement by submitting proof of the insurance required under this section.

(h) The Board shall specify on each license whether the license holder meets the insurance requirements of this section.