Montrose Environmental (NYSE: MEG) rebrands as Onterris with ONT ticker

Rhea-AI Filing Summary

Montrose Environmental Group, Inc. is changing its corporate name to Onterris, Inc. and its NYSE ticker from “MEG” to “ONT” effective at the start of trading on May 4, 2026. The amendment to the Amended and Restated Certificate of Incorporation and related bylaw changes were filed in Delaware and became effective on April 17, 2026 without a stockholder vote under Section 242 of Delaware law.

The name change does not affect the voting rights, validity or transferability of the existing common stock, and the CUSIP will remain the same. The company issued a press release on April 21, 2026 describing the new unified Onterris brand and its focus on environmental solutions.

8-K Event Classification

3 items: 5.03, 7.01, 9.01

3 items

Item 5.03 Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year Governance

The company amended its charter documents, bylaws, or changed its fiscal year.

Item 7.01 Regulation FD Disclosure Disclosure

Material non-public information disclosed under Regulation Fair Disclosure, often investor presentations or guidance.

Item 9.01 Financial Statements and Exhibits Exhibits

Financial statements, pro forma financial information, and exhibit attachments filed with this report.

Key Terms

Amended and Restated Certificate of Incorporation, Amended and Restated Bylaws, Section 242 of the General Corporation Law of the State of Delaware, Regulation FD Disclosure, +1 more

5 terms

Amended and Restated Certificate of Incorporation regulatory

"filed with the Secretary of State of the State of Delaware an amendment to its Amended and Restated Certificate of Incorporation"

A company’s amended and restated certificate of incorporation is an updated version of its foundational legal charter that replaces the older document and folds in all changes into one clear copy; it spells out corporate structure, classes of stock, shareholder rights and key governance rules. Investors care because it can change who controls the company, how votes are counted, what claims shareholders have on assets or dividends, and can introduce or remove protections against takeovers—like updating a house title after a major renovation to show who owns what and under what rules.

Amended and Restated Bylaws regulatory

"approved an amendment to the Company’s Amended and Restated Bylaws to conform to and further implement the Name Change"

A company’s amended and restated bylaws are its internal rulebook rewritten to include all changes in one updated document, replacing the old bylaws. For investors, this matters because the bylaws set how the board, shareholders and officers make decisions, hold votes and handle disputes; a new consolidated version can change voting rights, control mechanisms or procedures that affect corporate governance and the value or risk of an investment.

Section 242 of the General Corporation Law of the State of Delaware regulatory

"The Board approved the Name Change and the Amendment pursuant to Section 242 of the General Corporation Law of the State of Delaware"

Regulation FD Disclosure regulatory

"Item 7.01 Regulation FD Disclosure. On April 21, 2026, the Company issued a press release"

Regulation FD disclosure requires public companies to share important, market-moving information with everyone at the same time instead of tipping off analysts or large investors first. Think of it as making sure all players on a field hear the same announcement simultaneously; that fairness helps investors trust that stock prices reflect the same information and reduces the risk of sudden, unfair trading advantages or regulatory penalties for selective leaks.

forward-looking statements regulatory

"This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933"

Forward-looking statements are predictions or plans that companies share about what they expect to happen in the future, like estimating sales or profits. They matter because they help investors understand a company's outlook, but since they are based on guesses and assumptions, they can sometimes be wrong.

Understanding 8-K Material Events →

--12-31false000164361500016436152026-04-172026-04-17

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): April 17, 2026

Montrose Environmental Group, Inc.

(Exact name of Registrant as Specified in Its Charter)

Delaware			001-39394	46-4195044
(State or Other Jurisdiction of Incorporation)			(Commission File Number)	(IRS Employer Identification No.)
5120 Northshore Drive
North Little Rock, Arkansas				72118
(Address of Principal Executive Offices)				(Zip Code)

Registrant’s Telephone Number, Including Area Code: 501 900-6400

(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:

☐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 Symbol(s)		Name of each exchange on which registered
Common Stock, $0.000004 par value per share		MEG		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. ☐

Item 5.03 Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year.

On April 17, 2026, Montrose Environmental Group, Inc. (the “Company”) filed with the Secretary of State of the State of Delaware an amendment to its Amended and Restated Certificate of Incorporation, as amended (the “Amendment”), to change the name of the Company from “Montrose Environmental Group, Inc.” to “Onterris, Inc.” (the “Name Change”). The Name Change and the Amendment became effective immediately upon filing.

In connection with approving the Amendment, the Company’s Board of Directors (the “Board”) approved an amendment to the Company’s Amended and Restated Bylaws to conform to and further implement the Name Change, subject to and effective upon the Amendment. Accordingly, the amendment to the Bylaws became effective upon the filing of the Certificate of Amendment reflecting the Amendment with the Secretary of State of the State of Delaware on April 17, 2026.

The foregoing descriptions of the Amendment and the Bylaws do not purport to be complete and are qualified in their entirety by reference to the full text of the Certificate of Amendment and the Bylaws, respectively, copies of which are attached as Exhibits 3.1and 3.2, respectively, to this Current Report on Form 8-K and incorporated herein by reference.

The Board approved the Name Change and the Amendment pursuant to Section 242 of the General Corporation Law of the State of Delaware. Pursuant to Section 242, stockholder approval was not required to complete the Name Change or to approve or effect the Amendment. The Name Change will not in any way affect the voting or other rights that accompany the Company’s common stock, par value $0.000004 per share (“Common Stock”), or the validity or transferability of the Company’s shares of Common Stock currently outstanding.

The Company’s Common Stock will continue to be quoted on the New York Stock Exchange and will begin trading under the new name and ticker symbol “ONT” on May 4, 2026. There will be no change to the Company’s CUSIP in connection with the Name Change.

Item 7.01 Regulation FD Disclosure.

On April 21, 2026, the Company issued a press release announcing the Name Change. A copy of the press release is furnished as Exhibit 99.1 hereto and incorporated herein by reference.

The information included in this Item 7.01 and Exhibit 99.1 attached to this report is being furnished to the U.S. Securities and Exchange Commission and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, and shall not be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

Item 9.01 Financial Statements and Exhibits.

d) Exhibits:

Exhibit No.		Description
3.1		Certificate of Amendment to the Amended and Restated Certificate of Incorporation of Montrose Environmental Group, Inc., filed April 17, 2026
3.2		Amended and Restated Bylaws of Onterris, Inc.
99.1		Press release, dated April 21, 2026, issued by Onterris, Inc.
104		Cover Page Interactive Data File (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 thereunto duly authorized.

			Montrose Environmental Group, Inc.
Date:	April 21, 2026	By:	/s/ Allan Dicks
			Allan Dicks Chief Financial Officer

Exhibit 99.1

Montrose Environmental Group Is Now Onterris

Earth Day launch of new, unified brand highlights commitment “For Planet & Progress”

Little Rock, AR, April 21, 2026 — Montrose Environmental Group (NYSE: MEG, changing to ONT May 4, 2026) will mark Earth Day by rebranding to Onterris. The new, unified brand reflects a purpose and broader role in tackling complex environmental challenges with scientific rigor, operational quality and precise execution. It also aligns expertise and market awareness to position the Company for its next phase of growth. Founded 14 years ago and operating across the U.S., Canada and Australia, the Company is a leading pure-play environmental solutions provider. While the name is new, the mission remains unchanged: advancing our way of life without compromising the integrity of our environment.

At the heart of the new brand is a guiding principle: For Planet & Progress.

“Onterris is more than a new name. This brand reflects our company’s evolution and role in solving some of the defining environmental challenges of our time,” said Vijay Manthripragada, President and CEO of Onterris. “Our clients operate at the intersection of environmental responsibility, evolving regulatory frameworks and operational performance. By uniting our expertise across science, engineering, data and consulting, Onterris facilitates economic progress without compromising environmental stewardship, an approach that is especially meaningful as we celebrate Earth Day.”

A brand inspired by the Earth and the responsibility we share

The Onterris brand draws inspiration from the “pale blue dot,” the image of Earth captured by NASA’s Voyager 1 from more than four billion miles away. That perspective reinforces the shared responsibility for our home. Combining “on,” symbolizing motion and intent, with “terris,” meaning earth, the name reflects a belief in practical, innovative, science-driven solutions to the real-world challenges that communities and industries face every day.

One name, many solutions

Onterris unites the Company’s distinctive environmental consulting, testing and treatment expertise under one global identity. The transition brings together brands, including Montrose Environmental in the U.S. and Canada, as well as ECT2, CTEH and Enthalpy Analytical in the U.S., and Epic Environmental in Australia, creating a clearer, more consistent experience for clients and partners across regions and services. We believe this change will strengthen alignment, enhance client engagement and support continued long-term organic growth.

Built for a changing operating environment

Environmental challenges are increasingly interconnected. Resource constraints, public health impacts, climate pressures and a rapidly changing regulatory environment continue to reshape industries and redefine how organizations manage risk and support growth. Onterris uses science, technology, data and field execution through a unified, evolving platform, helping clients build resilience and reduce environmental and regulatory risk to protect air, water and soil. We believe bringing these capabilities together under the unified Onterris brand will enhance client service and scale solutions to meet growing demand. This approach reflects a core belief that environmental responsibility and human progress are fundamentally intertwined.

Exhibit 99.1

In connection with its name change, the Company will change the common stock ticker symbol as listed on the New York Stock Exchange from ‘MEG’ to ‘ONT’. Both the name and ticker symbol changes will become effective on the New York Stock Exchange at the start of trading on May 4, 2026.

Learn more about Onterris and how we support both planet and progress at www.onterris.com.

About Onterris

Onterris is a global environmental solutions company partnering with organizations to solve complex challenges where environmental pressures, regulatory expectations and operational risks intersect. Guided by our mission to advance the way of life without compromising the integrity of our environment, we believe environmental responsibility and human progress are fundamentally connected. Our scientists, engineers, field teams and consultants apply systems thinking that unites science, data and practical expertise to deliver solutions that strengthen our clients’ resilience, mitigate risk and help protect the air, water and soil that sustain communities, while uncovering responsible paths forward for planet and progress. For more information, visit www.onterris.com.

Forward‐Looking Statements

This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking statements may be identified by the use of words such as “intend,” “expect”, and “may”, and other similar expressions that predict or indicate future events or that are not statements of historical matters. Forward-looking statements are based on current information available at the time the statements are made and on management’s reasonable belief or expectations with respect to future events, and are subject to risks and uncertainties, many of which are beyond the Company’s control, that could cause actual performance or results to differ materially from the belief or expectations expressed in or suggested by the forward-looking statements. Additional factors or events that could cause actual results to differ may also emerge from time to time, and it is not possible for the Company to predict all of them. Forward-looking statements speak only as of the date on which they are made, and the Company undertakes no obligation to update any forward-looking statement to reflect future events, developments or otherwise, except as may be required by applicable law. Investors are referred to the Company’s filings with the Securities and Exchange Commission, including its Annual Report on Form 10-K for the year ended December 31, 2025 for additional information regarding the risks and uncertainties that may cause actual results to differ materially from those expressed in any forward-looking statement.

Contacts

Investor Relations:
Adrianne Griffin

Senior Vice President, Investor Relations & Treasury
(949) 988-3383
ir@montrose-env.com

Media Relations:
Lauren Dowling

Senior Vice President, Marketing & Communications

(214) 514-9809
laurendowling@montrose-env.com

FAQ

What corporate change did Montrose Environmental Group (MEG) announce in this 8-K?

Montrose Environmental Group announced it is changing its corporate name to Onterris, Inc. The change reflects a unified global brand for its environmental solutions business and became effective upon filing an amendment to its certificate of incorporation in Delaware.

When will Montrose Environmental’s stock start trading under the new ONT ticker?

The company’s common stock will begin trading on the New York Stock Exchange under the new ticker symbol ONT on May 4, 2026. Until that date, shares continue trading as MEG with no change to the existing CUSIP identifier for the stock.

Does the name change to Onterris affect MEG shareholders’ rights?

The name change will not affect voting rights, validity or transferability of existing common shares. The company explicitly states that rights attached to its common stock remain the same, and only the corporate name and trading symbol on the NYSE are changing.

Did Montrose Environmental need stockholder approval for the Onterris name change?

Stockholder approval was not required for the name change or the charter amendment. The board approved the changes under Section 242 of the Delaware General Corporation Law, which in this case allowed the amendment to proceed without a shareholder vote.

What governance documents did Montrose amend in connection with becoming Onterris?

The company filed a Certificate of Amendment to its Amended and Restated Certificate of Incorporation and approved corresponding amendments to its Amended and Restated Bylaws. These updates align the core corporate documents with the new Onterris, Inc. name and brand.

How did Montrose Environmental communicate the Onterris rebrand to the market?

The company issued a press release on April 21, 2026 announcing the rebrand to Onterris. That release, furnished as an exhibit, highlights the new unified brand, environmental solutions focus, and confirms the upcoming NYSE ticker change from MEG to ONT.

Filing Exhibits & Attachments

4 documents

Press Releases

• EX-99.1 EX-99.1 19.5 KB

Other Documents

• EX-3.1 EX-3.1 14.7 KB
• EX-3.2 EX-3.2 232.7 KB
• EX-101 XBRL TAXONOMY EXTENSION SCHEMA WITH EMBEDDED LINKBASES DOCUMENT 25.4 KB