It is easy for landlords to end a month-to-month tenancy in the District of Columbia -- as long as they are acting for a reason recognized as legitimate under the law. (The situation is more complicated when it comes to breaking a fixed-term lease.)
Subject to the District's eviction protection provisions (see below), your landlord can give you a written notice to move, allowing you 30 days as required by law and specifying the date on which your tenancy will end. Notice must be given on the date that rent is due, and the tenancy will expire on the next rent due date. If your lease includes a written waiver of notice of eviction in the case of nonpayment of rent, your landlord need not give notice if the reason for eviction is rent nonpayment.
However, giving the right amount of notice does a landlord no good unless the reason for the termination is one of the "just causes" for termination and eviction as ennumerated in the law. Residential tenants are covered by the District's "eviction protection" law, which specifies ten allowable reasons, or "just causes," for landlords to evict tenants. Your landlord may not legally terminate your lease unless the reason falls within the ten ennumerated situations. (D.C. Code Ann. § 42-3505.01)
It is easy for tenants in the District of Columbia to get out of a month-to-month rental agreement. You must provide the same amount of notice (30 days) as the landlord. Your notice to end the tenancy must be given on the same day of the month that the tenancy began -- usually, the first of the month, when rent is due.
In some situations, you may be able to move out with less (or no) notice—for example, if your landlord seriously violates the rental agreement or fails to fulfill legal responsibilities affecting your health or safety.
Check District of Columbia law (D.C. Code Ann. § 42-3202) for the exact rules and procedures for how landlords must prepare and serve termination notices and for any special rules regarding how tenants must provide notice. See the Laws and Legal Research section of Nolo for advice on finding and reading statutes and court decisions.
The District of Columbia Office of the Tenant Advocate publishes many helpful articles on tenant rights.