Md. Code Ann., Real Prop. § 8-203.1

(b) The landlord shall retain a copy of the receipt for a period of 2 years after the termination of the tenancy, abandonment of the premises, or eviction of the tenant, as the case may be.

(c) The landlord shall be liable to the tenant in the sum of $25 if the landlord fails to provide a written receipt for the security deposit.