Maryland Code, Courts and Judicial Proceedings § 5-1202

(b)(1) Notwithstanding any other provision of law, any payment toward, written or oral affirmation of, or any other activity on the debt that occurs after the expiration of the statute of limitations applicable to the consumer debt collection action does not revive or extend the limitations period.

(2) This subsection may not be interpreted to affect the statute of limitations applicable to a cause of action arising from a separate written agreement or written payment plan entered into by the debtor and the creditor or collector before the expiration of the statute of limitations applicable to the consumer debt collection action.