Most residential landlords require tenants to pay a security deposit to cover any repairs needed when the tenant moves out, or to cover the tenant’s failure to pay the last month's rent.

Laws vary from state to state, but many states have statutes that provide the maximum amount of security deposit a landlord may require for a residential lease and the costs for which the landlord may use the security deposit (cleaning, repairs, unpaid rent) following termination of the lease.

These laws also provide a specific deadline (often 30-60 days) for the landlord to return the tenant’s security deposit following termination of the lease—after deducting any amount properly withheld, as allowed by law.

In Maryland, residential landlords can require tenants to pay a security deposit, which is regulated under state law. The maximum security deposit a landlord may require is equivalent to two months' rent. Landlords are permitted to use the security deposit for covering the cost of damages beyond normal wear and tear, cleaning the property to return it to the condition it was in at the start of the tenancy, and for unpaid rent. Maryland law requires landlords to return the security deposit within 45 days after the end of the tenancy. If any portion of the deposit is withheld, the landlord must provide the tenant with a written list of damages claimed and the cost of repairs. Additionally, landlords are required to hold security deposits in a separate, interest-bearing account and return it with accrued interest, minus any valid deductions, when the tenancy ends.