Maryland Code, Labor and Employment § 8-638

(1) an adjustment in connection with contributions then due; or

(2) if an adjustment cannot be made, a refund.

(1) 1 year from the date on which the payment was made; or

(2) 4 years from the last day of the calendar quarter for which the payment was made.

(c)(1) If the Secretary determines that the contested amount or any part of it was collected erroneously, the Secretary shall:

(2) The Secretary shall refund a contribution that was collected erroneously from the Unemployment Insurance Fund and interest that was collected erroneously from the Special Administrative Expense Fund.

(3) If an employing unit reported wages that have been included in the determination of an eligible claimant for benefits, the Secretary shall reduce any adjustment or refund by the amount of benefits received by the claimant that are chargeable to the employing unit.

(e)(1) If a claim for an adjustment or refund is rejected, the Secretary shall send a written notice of rejection to the employing unit.

(2) The Secretary's determination under paragraph (1) of this subsection is final and not subject to appeal if the employing unit does not request a review determination in accordance with § 8-604 of this subtitle within 30 days after the notice is sent to the employing unit.

(1) authorize an adjustment or refund of money that was due under the law in effect at the time that the money was paid; or

(2) prohibit a refund required under § 8-640 of this subtitle.