Company: OSBC
Filing Date: 2025-04-23
Form Type: S-4
Source: 0001104659-25-037832
Chunk: 375

Company: OLD SECOND BANCORP INC
Filing Date: 2025-04-23
Form: S-4
Chunk 375
---
 2007

A-1-9

TABLE OF CONTENTS

### EXHIBIT B

### FORM OF BANK AGREEMENT OF MERGER

### AGREEMENT TO MERGE
<div align='center'>among</div>

### EVERGREEN BANK GROUP
<div align='center'>and</div>

### OLD SECOND NATIONAL BANK
<div align='center'>under the charter of</div>

### OLD SECOND NATIONAL BANK
This AGREEMENT TO MERGE (this “

#### Agreement
”) is made as of [•], 2025 by and among EVERGREEN BANK GROUP (“

#### Evergreen Bank
”), an Illinois-chartered banking corporation, being headquartered at 1515 West 22 nd Street, Suite 100W, City of Oak Brook, County of DuPage, in the State of Illinois, and OLD SECOND NATIONAL BANK (hereinafter referred to as “

#### Old Second Bank
”), a national banking association organized under the laws of the United States, being headquartered at 37 South River Street, City of Aurora, County of Kane, in the State of Illinois.

#### WHEREAS,
Old Second Bancorp, Inc., the parent company of Old Second Bank (“

#### Old Second
”), and Bancorp Financial, Inc., the parent company of Evergreen Bank (“

### Bancorp Financial
”), have entered into that certain Agreement and Plan of Merger, dated as of February [•], 2025 (as such agreement may be subsequently amended or modified, the “

#### Merger Agreement
”), pursuant to which, subject to the terms and conditions of the Merger Agreement, Bancorp Financial shall merge with and into Old Second (the “

#### Merger
”);

#### WHEREAS,
the Merger Agreement contemplates that following the consummation of the Merger and pursuant to this Agreement, Evergreen Bank will merge with and into Old Second Bank (the “

#### Bank Merger
”); and

#### WHEREAS,
the boards of directors of each of Evergreen Bank and Old Second Bank have approved this Agreement and the transactions contemplated hereby, including the Bank Merger.

#### NOW, THEREFORE,
the parties hereto hereby agree as follows:

#### Section 1.
At the Effective Time (as defined below) Evergreen Bank shall be merged into Old Second Bank under the charter of the latter. Old Second Bank shall be the surviving entity of the Bank Merger and shall continue its existence as a national banking association following the consummation of the Bank Merger (the