Md. Code, Real Property § 14-126

(a) (1) In this section the following words have the meanings indicated.

(2) “Emergency services” includes fire, rescue, and ambulance services and a mobile crisis team as defined in § 10–1401 of the Health – General Article.

(3) “Governing body” has the meaning stated in § 1–101 of the Local Government Article.

(4) “Municipality” has the meaning stated in § 1–101 of the Local Government Article.

(5) “Rental license” means any certificate, license, or permit required to rent residential real property issued by a county or a municipality.

(6) (i) “Short–term rental unit” means a residential dwelling unit or a portion of the unit used to provide housing for less than 31 consecutive days.

(ii) “Short–term rental unit” does not include a hotel or motel, boarding house, group residential facility for students, fraternity or sorority house, or similar housing.

(b) This section does not apply to a local law or ordinance governing:

(1) The installation and use of residential security alarm systems;

(2) The physical condition, sanitation, maintenance, or repair of real property, including vacant buildings;

(3) Parking enforcement;

(4) Calls to law enforcement concerning social gatherings or excessive noise that do not involve an offense set forth in the Criminal Law Article and are:

(i) Made with the intent to harass another; or

(ii) Knowingly false, as a whole or in material part; or

(5) Short–term rental units.

(c) (1) The governing body of a county or a municipality may not enact or enforce a local law or ordinance that:

(i) Establishes a threshold of requests to summon law enforcement or emergency services to a residential property as grounds for designating a property as a nuisance; or

(ii) Penalizes or authorizes a penalty against an operator, an owner, an owner–occupant, or a tenant for:

1. The act of summoning law enforcement or emergency services to a residential property; or

2. The actions of another individual to summon the assistance of law enforcement or emergency services to a residential property.

(2) There is a presumption that a local law or ordinance relating to summoning law enforcement or emergency services to a residential property is prohibited under paragraph (1)(ii) of this subsection if the local law or ordinance authorizes or requires:

(i) The assessment of a monetary penalty or fine on an operator, an owner, an owner–occupant, or a tenant;

(ii) The use of an action for repossession of a dwelling unit from a tenant or termination or nonrenewal of a tenant’s lease; or

(iii) The revocation, suspension, or nonrenewal of a rental license.

(d) An operator, an owner, an owner–occupant, or a tenant may raise the issue that a local law or ordinance is prohibited under subsection (c) of this section:

(1) As a defense to an action to enforce the local law or ordinance; or

(2) As an affirmative claim for damages resulting from the enforcement of the law or ordinance.

(e) If in any proceeding the court finds in favor of the operator, owner, owner–occupant, or tenant, the court may enter a judgment against the county or municipality attempting to enforce the prohibited local law or ordinance and award the operator, owner, owner–occupant, or tenant:

(1) Reasonable damages;

(2) Reasonable attorney’s fees;

(3) Court costs;

(4) Reinstatement of a rental license; and

(5) Other relief as deemed appropriate by the court.