Marten Transport, Ltd.

Item 1.01. Entry into a Material Definitive Agreement. On August 16, 2022, Marten Transport, Ltd. (“Marten”) entered into a credit agreement (the “Credit Agreement”) with U.S. Bank National Association, as agent (the “Agent”), and certain banks party thereto (the “Banks”). The Credit Agreement provides for a five-year unsecured revolving credit facility in an aggregate principal amount of up to $30 million. Certain subsidiaries of Marten guarantee Marten’s obligations under the Credit Agreement and any other subsidiary of Marten that guaranties any material indebtedness of Marten is obligated to also guaranty Marten’s obligations under the Credit Agreement. From time to time the aggregate principal amount of the revolving credit facility may be increased and a term loan facility may be added at the option of Marten after providing notice to the Agent in increments not less than $5 million up to a maximum aggregate principal amount of $100 million. The credit facility has a $30 million sublimit for the issuance of letters of credit. Funds are available under the credit facility for Marten’s general business and working capital purposes. On June 12, 2026, Marten entered into the First Amendment to Credit Agreement (the “First Amendment”) to increase the sublimit for the issuance of letters of credit from $30 million to $35 million and increase the maximum aggregate principal amount from $100 million to $105 million. In addition, the First Amendment provides for an Amended and Restated Revolving Note under Credit Agreement in an aggregate principal amount of up to $35 million. On August 19, 2026, Marten entered into the Second Amendment to Credit Agreement (the “Second Amendment”) to update the applicable margins for Term SOFR advances, increase the sublimit for the issuance of letters of credit from $35 million to $50 million, decrease the maximum aggregate principal amount from $105 million to $100 million and extend the term until August 19, 2031. In addition, the Second Amendment provides for a Second Amended and Restated Revolving Note under Credit Agreement in an aggregate principal amount of up to $50 million. The foregoing description of the Second Amendment is qualified in its entirety by reference to the Second Amendment, a copy of which will be attached to Marten’s next Quarterly Report on Form 10-Q. Section 2 - Financial Information

Item 2.03 Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information described under Item 1.01 “Entry into a Material Definitive Agreement” is incorporated herein by this reference.