# EDGAR Filing Document

**Accession Number:** 0001004434
**File Stem:** 0001193125-26-076911
**Filing Date:** 2026-2
**Character Count:** 13124
**Document Hash:** 13f39326a74813d2baf7d773f1330bd5
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-076911.hdr.sgml**: 20260226

**ACCESSION NUMBER**: 0001193125-26-076911

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 15

**CONFORMED PERIOD OF REPORT**: 20260222

**ITEM INFORMATION**: Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

**ITEM INFORMATION**: Regulation FD Disclosure

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20260226

**DATE AS OF CHANGE**: 20260226

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** AFFILIATED MANAGERS GROUP, INC.
- **CENTRAL INDEX KEY:** 0001004434
- **STANDARD INDUSTRIAL CLASSIFICATION:** INVESTMENT ADVICE [6282]
- **ORGANIZATION NAME:** 02 Finance
- **EIN:** 043218510
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-13459
- **FILM NUMBER:** 26689399

**BUSINESS ADDRESS:**
- **STREET 1:** 777 SOUTH FLAGLER DRIVE
- **STREET 2:** SUITE 1401 EAST TOWER
- **CITY:** WEST PALM BEACH
- **STATE:** FL
- **ZIP:** 33401
- **BUSINESS PHONE:** (800) 345-1100

**MAIL ADDRESS:**
- **STREET 1:** 777 SOUTH FLAGLER DRIVE
- **STREET 2:** SUITE 1401 EAST TOWER
- **CITY:** WEST PALM BEACH
- **STATE:** FL
- **ZIP:** 33401

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** AFFILIATED MANAGERS GROUP INC
- **DATE OF NAME CHANGE:** 19970822

?xml version='1.0' encoding='ASCII'? 8-K

### 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): February 22, 2026

## AFFILIATED MANAGERS GROUP, INC.

#### (Exact Name of Registrant as Specified in Its Charter)

#### Delaware

#### (State or Other Jurisdiction

#### of Incorporation)

---

| | |
|:---|:---|
| **001-13459** | **04-3218510** |
| **(Commission**<br> **File Number)** | **(IRS Employer**<br> **Identification No.)** |

---

#### 777 South Flagler Drive, West Palm Beach, Florida 33401

#### (Address of Principal Executive Offices)
(800) 345-1100

#### (Registrant's Telephone Number, Including Area Code)

#### N/A

#### (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 (*see* General Instruction A.2. below):

☐ 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:

---

| | | |
|:---|:---|:---|
| **Title of each class** | **Trading**<br> **Symbol(s)** | **Name of each exchange**<br> **on which registered** |
| **Common Stock ($0.01 par value)** | **AMG** | **New York Stock Exchange** |
| **5.875% Junior Subordinated Notes due 2059** | **MGR** | **New York Stock Exchange** |
| **4.750% Junior Subordinated Notes due 2060** | **MGRB** | **New York Stock Exchange** |
| **4.200% Junior Subordinated Notes due 2061** | **MGRD** | **New York Stock Exchange** |
| **6.750% Junior Subordinated Notes due 2064** | **MGRE** | **New York Stock Exchange** |

---

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. ☐

------

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| | |
|:---|:---|
| **ITEM 5.02** | **Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.**  |

---

On February 26, 2026, Affiliated Managers Group, Inc. (the "Company") announced the appointment of G. Staley Cates to its Board of Directors (the "Board"), as an independent director, effective April 1, 2026.

Mr. Cates served as the Vice Chairman of Southeastern Asset Management, Inc. ("Southeastern"), an independent global investment management firm, from 2015 through 2024, having served as President from 1989 through 2015 after joining Southeastern in 1986. Mr. Cates is a Co-Founder of the New Hope Christian Academy, was a founding board member of the Soulsville Foundation, and was the Founding Chairman of the Memphis Grizzlies Charitable Foundation and of the Board of Crosstown Concourse. He serves as the Chairman of the Poplar Foundation, which supports various educational initiatives in Memphis, and was the Governor's appointee to the Transition Planning Commission for the consolidation of Memphis City and Shelby County schools between 2011 and 2012. Mr. Cates received a B.A. from the University of Texas at Austin and is a Chartered Financial Analyst.

Mr. Cates will participate in the Company's customary director compensation program, as described in the Company's proxy statement for its most recent annual meeting of stockholders and in the Company's periodic filings with the Securities and Exchange Commission ("SEC"). In addition, Mr. Cates and the Company will enter into the Company's standard indemnification agreement for directors and executive officers, a form of which has been previously filed by the Company with the SEC. There is no arrangement or understanding between Mr. Cates or any other person pursuant to which he was elected as a director of the Company, and there are no familial relationships between him and any of the Company's directors or executive officers. Mr. Cates, including his immediate family members, is not a party, directly or indirectly, to any related person transaction required to be reported pursuant to Item 404(a) of Regulation S-K.

Separately, on February 22, 2026, Karen L. Alvingham notified the Company of her decision to retire from the Board, effective April 1, 2026.

On February 26, 2026, the Company also announced the re-appointment of Jay C. Horgen as President of the Company, effective April 1, 2026. Mr. Horgen will also continue to serve as Chief Executive Officer.

Information about Mr. Horgen required under Item 401(b), (d) and (e), and Item 404(a) of Regulation S-K is incorporated by reference from the Company's definitive proxy statement on Schedule 14A for its 2025 annual meeting of stockholders, filed on April 11, 2025.

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| | |
|:---|:---|
| **ITEM 7.01** | **Regulation FD Disclosure.**  |

---

On February 26, 2026, the Company issued a press release announcing the matters described above, which is furnished as Exhibit 99.1 hereto and shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or otherwise subject to the liability of that section, nor shall it be deemed incorporated by reference into any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing.

---

| | |
|:---|:---|
| **ITEM 9.01** | **Financial Statements and Exhibits.**  |

---

(d) Exhibits.

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| | |
|:---|:---|
| **Exhibit<br>No.** | **Description** |
| 99.1 | [Press Release issued by the Company on February 26, 2026.](d113085dex991.htm) |
| 104 | Cover Page Interactive Data File (the cover page tags are embedded within the Inline XBRL document). |

---

------

#### 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.

---

| | | |
|:---|:---|:---|
|  | AFFILIATED MANAGERS GROUP, INC. | AFFILIATED MANAGERS GROUP, INC. |
| Date: February 26, 2026 | By: | /s/ Kavita Padiyar |
|  | Name: | Kavita Padiyar |
|  | Title: | General Counsel and Corporate Secretary |

---

## Exhibit 99.1

**Exhibit 99.1** 

---

| | | |
|:---|:---|:---|
| ![LOGO](g113085g0226090240740.jpg) | AMG Media & Investor Relations: | Patricia Figueroa<br> (617) 747-3300 ir@amg.com pr@amg.com |

---

**AMG Appoints G. Staley Cates to its Board of Directors** 

*Karen L. Alvingham to Retire from Board of Directors* 

**WEST PALM BEACH, FL, February 26, 2026 –** AMG, a strategic partner to leading independent investment management firms globally, today announced the appointment of G. Staley Cates to its Board of Directors (the "Board"), effective April 1, 2026; the Company also announced the forthcoming retirement of Karen L. Alvingham from the Board, effective April 1, 2026. Lady Alvingham was appointed to AMG's Board of Directors in January 2018.

Mr. Cates served as the Vice Chairman of Southeastern Asset Management, Inc. ("Southeastern"), an independent global investment management firm, from 2015 through 2024, having served as President from 1989 through 2015 after joining Southeastern in 1986. Mr. Cates is a Co-Founder of the New Hope Christian Academy, was a founding board member of the Soulsville Foundation, and was the Founding Chairman of the Memphis Grizzlies Charitable Foundation and of the Board of Crosstown Concourse. He serves as the Chairman of the Poplar Foundation, which supports various educational initiatives in Memphis, and was the Governor's appointee to the Transition Planning Commission for the consolidation of Memphis City and Shelby County schools between 2011 and 2012. Mr. Cates received a B.A. from the University of Texas at Austin and is a Chartered Financial Analyst.

"We are pleased to welcome Staley Cates to AMG's Board of Directors," said Loren M. Starr, Chair of AMG's Board of Directors. "Staley is a distinguished investor and business leader whose four decades at Southeastern were defined by a deep commitment to long-term value creation, disciplined capital allocation, and shareholder alignment; Staley will bring unique insight to our boardroom. I would also like to express the Board's sincere appreciation to Karen for her dedicated service and thoughtful counsel during a pivotal period of growth and evolution for AMG – she will be missed."

"It has been an honor to serve on AMG's Board over the past eight years," said Lady Alvingham. "I have great respect for the firm's commitment to its shareholders, Affiliates, and clients, and I depart with great appreciation for the opportunity to contribute to AMG's evolution and success."

The Company also announced the re-appointment of Jay C. Horgen as President, effective April 1, 2026. Mr. Horgen will also continue to serve as Chief Executive Officer.

**About AMG** 

AMG (NYSE: AMG) is a strategic partner to leading independent investment management firms globally. AMG's strategy is to generate long-term value by investing in high-quality independent partner-owned firms, through a proven partnership approach, and allocating resources across AMG's unique opportunity set to the areas of highest growth and return. Through its distinctive approach, AMG magnifies its Affiliates' existing advantages and actively supports their independence and ownership culture. As of December 31, 2025, AMG's aggregate assets under management were approximately $813 billion across a diverse range of private markets, liquid alternative, and differentiated long-only investment strategies. For more information, please visit the Company's website at <u>www.amg.com</u>.

*Certain matters discussed in this press release issued by Affiliated Managers Group, Inc. ("AMG" or the "Company") may constitute forward-looking statements within the meaning of the federal securities laws, and could be impacted by a number of factors, including those described under the section entitled "Risk Factors" in AMG's most recent Annual Report on Form 10-K, as such factors may be updated from time to time in the Company's periodic filings with the SEC, which are accessible on the SEC's website at www.sec.gov. AMG undertakes no obligation to publicly update or review any forward-looking statements, whether as a result of new information, future developments or otherwise, except as required by applicable law. This release does not constitute an offer of any products, investment vehicles, or services of any AMG Affiliate. From time to time, AMG may use its website as a distribution channel of material Company information. AMG routinely posts financial and other important information regarding the Company in the Investor Relations section of its website at www.amg.com and encourages investors to consult that section regularly.*