HEARTLAND EXPRESS INC

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported):

April 16, 2026

HEARTLAND EXPRESS, INC.

(Exact name of registrant as specified in its charter)

(319)626-3600

Registrant's Telephone Number (including area code):

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

On April 16, 2026, David P. Millis, President of Millis Transfer and a director of Heartland Express, Inc. (the “Company”), informed the Company of his decision to retire as President of Millis Transfer, effective April 24, 2026. Mr. Millis will continue to serve as a director of the Company following his retirement.

In association with his retirement, Mr. Millis will receive compensation and insurance benefits totaling $66,766 and 4,866 shares of common stock. The Company would like to thank Mr. Millis for his service and leadership to Millis Transfer during his tenure. Additionally, effective as of the date his retirement, Mr. Millis will be eligible to receive compensation for services as a director consistent with that of the other non-employee directors of the Company, as described under "