UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

SCHEDULE 13D

(Rule 13d-101)

Information to be Included in Statements Filed Pursuant

to § 240.13d-1(a) and Amendments Thereto Filed

Pursuant to § 240.13d-2(a)

Under the Securities Exchange Act of 1934

(Amendment No. 3)

Surgery Partners, Inc.

(Name of Issuer)

Common Stock, $0.01

par value per share

(Title of Class of Securities)

86881A 100

(CUSIP Number)

Bain Capital Investors, LLC

200 Clarendon Street

Boston, MA 02116

617-516-2000

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

May 17, 2021

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.  ☐

Note. Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See § 240.13d-7 for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934, as amended (“Act”), or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

This Amendment No. 3 relates to the shares of common stock, $0.01 par value per share (the “Common Stock”), of Surgery Partners, Inc., a Delaware corporation (the “Issuer”), and amends the initial statement on Schedule 13D filed by BCPE Seminole Holdings LP on September 8, 2019, as amended by Amendment No. 1 filed on December 15, 2017 and Amendment No. 2 filed on February 12, 2021 (the “Initial Statement” and, as further amended by this Amendment No. 3, the “Statement”). Capitalized terms used but not defined herein shall have the meanings ascribed to them in the Initial Statement and unless amended and restated hereby, all information in the Initial Statement remains in effect, as supplemented hereby.

Item 2. Identity and Background

Sections (a) and (b) of Item 2 of the Initial Statement are hereby amended and restated as follows:

BCPE Seminole GP LLC, a Delaware limited liability company (“Seminole GP”), is the general partner of the Reporting Person. Bain Capital Investors, LLC (“BCI,” and collectively with the Reporting Person and Seminole GP, the “Bain Capital Entities”), is the sole member of Seminole GP. As a result, BCI may be deemed to share voting and dispositive power with respect to the securities held by the Reporting Person. Voting and investment decisions with respect to securities held by the Reporting Person are made by the managing directors of BCI.

The principal business address for each of the Bain Capital Entities is c/o Bain Capital Private Equity, LP, 200 Clarendon Street, Boston, Massachusetts 02116.

Item 5. Interest in Securities of the Issuer

Item 5 of the Initial Statement is hereby amended and restated as follows:

The information set forth in or incorporated by reference in Items 2, 3 and 4 and on the cover pages of this Statement is incorporated by reference in its entirety into this Item 5.

Ownership percentages set forth in this Statement are based upon (i) a total of 59,890,985 shares of Common Stock issued and outstanding as of April 28, 2021, as reported by the Issuer in its Quarterly Report on Form 10-Q for the quarter ended March 31, 2021, filed with the Securities and Exchange Commission on May 5, 2021 and (ii) 22,608,925 shares of Common Stock issued by the Issuer on May 17, 2021 upon the conversion of 310,000 shares of Series A Preferred Stock.

SIGNATURE

After reasonable inquiry and to the best of its knowledge and belief, the undersigned certifies that the information set forth in this statement is true, complete and correct.