Form 8-K FIRST BUSINESS FINANCIAL For: Jul 30

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

First Business Financial Services, Inc.

(Exact name of Registrant as Specified in Its Charter)

(Former Name or Former Address, if Changed Since Last Report)

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:

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. ☐

Item 2.02 Results of Operations and Financial Condition.

On July 30, 2026, First Business Financial Services, Inc. (the “Company”) announced its earnings for the quarter ended June 30, 2026, as well as the declaration of a quarterly cash dividend on its common stock and 7% series A preferred stock. A copy of the Company’s press release containing this information is being “furnished” as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference.

Item 7.01 Regulation FD Disclosure.

On July 30, 2026, the Company posted an earnings call presentation to its website www.firstbusiness.bank under the “Investor Relations” tab. The information included in the presentation provides an overview of the Company’s recent operating performance, financial condition, and business strategy. The Company intends to use this presentation in connection with its second quarter 2026 earnings call to be held at 8:00 a.m. Central time on July 31, 2026, and from time to time when the Company's executives interact with shareholders, analysts, and other third parties. A copy of the registrant’s presentation is attached hereto as Exhibit 99.2 to this Current Report on Form 8-K and is incorporated herein by reference.

The information in Items 2.02 and 7.01 of this Current Report on Form 8-K and Exhibits 99.1 and 99.2 attached hereto is being “furnished” and will not, except to the extent required by applicable law or regulation, be deemed “filed” by the Company for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor will any of such information or exhibits be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, except as expressly set forth by specific reference in such filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

The following exhibit is being “furnished” as part of this Current Report on Form 8-K:

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.