# EDGAR Filing Document

**Accession Number:** 0000773757
**File Stem:** 0001193125-26-275796
**Filing Date:** 2026-6
**Character Count:** 9499
**Document Hash:** f0bc85c197ee5ff5a567b68a9fb60d5a
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-275796.hdr.sgml**: 20260618

**ACCESSION NUMBER**: 0001193125-26-275796

**CONFORMED SUBMISSION TYPE**: 425

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20260618

**DATE AS OF CHANGE**: 20260618

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** COLUMBIA FUNDS SERIES TRUST
- **CENTRAL INDEX KEY:** 0001097519

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 0331

**FILING VALUES:**
- **FORM TYPE:** 425
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 811-09645
- **FILM NUMBER:** 261102433

**BUSINESS ADDRESS:**
- **STREET 1:** 290 CONGRESS STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02210
- **BUSINESS PHONE:** 800-345-6611

**MAIL ADDRESS:**
- **STREET 1:** 290 CONGRESS STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02210

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** NATIONS FUNDS TRUST
- **DATE OF NAME CHANGE:** 19991022
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** COLUMBIA FUNDS SERIES TRUST I
- **CENTRAL INDEX KEY:** 0000773757
- **STANDARD INDUSTRIAL CLASSIFICATION:** UNKNOWN SIC - 0000 [0000]

**ORGANIZATION NAME:**
- **EIN:** 363376651
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 0630

**FILING VALUES:**
- **FORM TYPE:** 425

**BUSINESS ADDRESS:**
- **STREET 1:** 290 CONGRESS STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02210
- **BUSINESS PHONE:** 800-345-6611

**MAIL ADDRESS:**
- **STREET 1:** 290 CONGRESS STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02210

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** COLUMBIA FUNDS TRUST IX
- **DATE OF NAME CHANGE:** 20031107

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** LIBERTY STEIN ROE FUNDS MUNICIPAL TRUST
- **DATE OF NAME CHANGE:** 19991025

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** STEINROE MUNICIPAL TRUST
- **DATE OF NAME CHANGE:** 19920703
**CENTRAL INDEX KEY**: 0000773757

**CENTRAL INDEX KEY**: 0001097519

**CENTRAL INDEX KEY**: 0000773757

**CENTRAL INDEX KEY**: 0001097519

**CENTRAL INDEX KEY**: 0000773757

**CENTRAL INDEX KEY**: 0001097519

**CENTRAL INDEX KEY**: 0000773757

**CENTRAL INDEX KEY**: 0001097519

**CENTRAL INDEX KEY**: 0000773757

**CENTRAL INDEX KEY**: 0001097519

**CENTRAL INDEX KEY**: 0000773757

**CENTRAL INDEX KEY**: 0001097519

## Series and Classes Contracts Data

### Columbia Cornerstone Growth Fund (Series ID: S000012081)

| Class ID   | Class Name                               | Ticker Symbol   |
|:---|:---|:---|
| C000032910 | Columbia Cornerstone Growth Fund Class A | LEGAX           |

### Columbia Large Cap Growth Opportunity Fund (Series ID: S000010797)

| Class ID   | Class Name                                         | Ticker Symbol   |
|:---|:---|:---|
| C000029874 | Columbia Large Cap Growth Opportunity Fund Class A | NFEAX           |

### Columbia Cornerstone Growth Fund (Series ID: S000012081)

| Class ID   | Class Name                                           | Ticker Symbol   |
|:---|:---|:---|
| C000032915 | Columbia Cornerstone Growth Fund Institutional Class | GEGTX           |

### Columbia Large Cap Growth Opportunity Fund (Series ID: S000010797)

| Class ID   | Class Name                                                     | Ticker Symbol   |
|:---|:---|:---|
| C000029877 | Columbia Large Cap Growth Opportunity Fund Institutional Class | NFEPX           |

### Columbia Cornerstone Growth Fund (Series ID: S000012081)

| Class ID   | Class Name                                             | Ticker Symbol   |
|:---|:---|:---|
| C000078989 | Columbia Cornerstone Growth Fund Institutional 3 Class | CGFYX           |

### Columbia Large Cap Growth Opportunity Fund (Series ID: S000010797)

| Class ID   | Class Name                                                       | Ticker Symbol   |
|:---|:---|:---|
| C000171353 | Columbia Large Cap Growth Opportunity Fund Institutional 3 Class | CLRYX           |

### Columbia Cornerstone Growth Fund (Series ID: S000012081)

| Class ID   | Class Name                               | Ticker Symbol   |
|:---|:---|:---|
| C000094688 | Columbia Cornerstone Growth Fund Class R | CGWRX           |

### Columbia Large Cap Growth Opportunity Fund (Series ID: S000010797)

| Class ID   | Class Name                                         | Ticker Symbol   |
|:---|:---|:---|
| C000175686 | Columbia Large Cap Growth Opportunity Fund Class R | CLGPX           |

### Columbia Cornerstone Growth Fund (Series ID: S000012081)

| Class ID   | Class Name                                             | Ticker Symbol   |
|:---|:---|:---|
| C000094690 | Columbia Cornerstone Growth Fund Institutional 2 Class | CLWFX           |

### Columbia Large Cap Growth Opportunity Fund (Series ID: S000010797)

| Class ID   | Class Name                                                       | Ticker Symbol   |
|:---|:---|:---|
| C000136868 | Columbia Large Cap Growth Opportunity Fund Institutional 2 Class | CADRX           |

### Columbia Cornerstone Growth Fund (Series ID: S000012081)

| Class ID   | Class Name                               | Ticker Symbol   |
|:---|:---|:---|
| C000253720 | Columbia Cornerstone Growth Fund Class S | GEGDX           |

### Columbia Large Cap Growth Opportunity Fund (Series ID: S000010797)

| Class ID   | Class Name                                         | Ticker Symbol   |
|:---|:---|:---|
| C000253707 | Columbia Large Cap Growth Opportunity Fund Class S | NFEDX           |

Filing by Columbia Funds Series Trust I pursuant to Rule 425 under the Securities Act of 1933, and deemed

filed under Rule 14a-12(b) under the Securities Exchange Act of 1934.

Subject Company:

Columbia Funds Series Trust

(SEC File No. 811-09645)

------

**Supplement dated June 18, 2026**

to the Prospectus, Summary Prospectus, and Statement of Additional Information (SAI),

each as supplemented as applicable, of the following fund:

---

| | | |
|:---|:---|:---|
| **Fund** | **Prospectus and Summary Prospectus Dated** | **SAI Dated** |
| Columbia Funds Series Trust |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Columbia Large Cap Growth Opportunity Fund | 7/1/2025 | 6/1/2026 |

---

At a meeting held on June 18, 2026, the Boards of Trustees of Columbia Funds Series Trust and Columbia Funds Series Trust I (the Board) approved an Agreement and Plan of Reorganization pursuant to which Columbia Large Cap Growth Opportunity Fund (the Target Fund) will transfer all of its assets and liabilities to Columbia Cornerstone Growth Fund (the Acquiring Fund) in exchange for shares of the Acquiring Fund (the Reorganization).

Pursuant to applicable law (including the Investment Company Act of 1940), the Reorganization does not require shareholder approval, and shareholders will not be asked to vote on the Reorganization. Target Fund shareholders of record will be sent a combined Information Statement/Prospectus (the Combined Information Statement/Prospectus) containing further information regarding the Reorganization and the Acquiring Fund. The Reorganization is expected to close in the fourth quarter of 2026 (the Reorganization Date) and is expected to be a tax-free reorganization for U.S. federal income tax purposes.

Columbia Management Investment Advisers, LLC (the Investment Manager) serves as the investment adviser to each of the Target Fund and Acquiring Fund. During the period leading up to the Reorganization, the Investment Manager will seek to align the portfolio of the Target Fund with that of the Acquiring Fund. During this time, the Target Fund may not be pursuing its investment objectives and strategies, and limitations on permissible investments and investment restrictions will not apply. The sales and purchases of securities during the transition period are expected to result in buy and sell transactions and such transactions may be made at a disadvantageous time. In addition to the transaction costs associated with this repositioning of the Target Fund's portfolio in connection with the Reorganization, such sell transactions could result in increased taxable distributions to Target Fund shareholders holding shares in a taxable account.

*The foregoing is not an offer to sell, nor a solicitation of an offer to buy, shares of the Acquiring Fund, nor is it a solicitation of any proxy. Because the Target Fund will reorganize into the Acquiring Fund on the Reorganization Date, you should consider the appropriateness of making a new or subsequent investment in the Target Fund prior to the Reorganization Date. You should consider the investment objectives, risks, strategies, fees and expenses of the Acquiring Fund and Target Fund carefully before investing. To obtain the Acquiring Fund's current prospectus, shareholder reports and other regulatory filings, or to receive a free copy of the Combined Information Statement/Prospectus, once it is available, contact your financial intermediary or visit columbiathreadneedleus.com. The Combined Information Statement/Prospectus will contain important information about the Target Fund and Acquiring Fund's investment objective, strategies, risks, fees, expenses, and the Board's considerations in approving the Reorganization. The Combined Information Statement/Prospectus also will be available for free on the Securities and Exchange Commission's website (www.sec.gov).*

*Shareholders should retain this Supplement for future reference.*

SUP186_02_010_(06/26)

------