Montrose Environmental : 2Q21 Earnings Call Presentation

The Future of

Environmental

Solutions

Second Quarter 2021

Earnings Call

August 11, 2021

Safe Harbor

Statements contained herein and in the accompanying oral presentation contain 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 Montrose Environmental Group, Inc.'s ("Montrose," "we," "us" and "our") 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. Further, many of these factors are, and may continue to be, amplified by the COVID-19 pandemic. Additional factors or events that could cause actual results to differ may also emerge from time to time, and it is not possible for us to predict all of them. Forward-looking statements speak only as of the date on which they are made, and we undertake 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 Montrose's filings with the Securities and Exchange Commission, including its Annual Report on Form 10-K for the year ended December 31, 2020, for additional information regarding the risks and uncertainties that may cause actual results to differ materially from those expressed in any forward-looking statement.

Included in this presentation and the accompanying oral presentation are certain financial measures that are not calculated in accordance with U.S. generally accepted accounting principles ("GAAP") designed to supplement, and not substitute, Montrose's financial information presented in accordance with GAAP. The non-GAAP measures as defined by Montrose may not be comparable to similar non-GAAP measures presented by other companies. The presentation of such measures, which may include adjustments to exclude unusual or non-recurring items, should not be construed as an inference that Montrose's future results, cash flows or leverage will be unaffected by other unusual or nonrecurring items. Please see the appendix to this presentation for how we define these non-GAAP measures, a discussion of why we believe they are useful to investors and certain limitations thereof, and reconciliations thereof to the most directly comparable GAAP measures.

The data included in this presentation regarding markets and the industry in which we operate, including the size of certain markets, are based on publicly available information, reports of government agencies, and published industry sources such as Environmental Business International, Inc. ("EBI"). In presenting this information, we have also made certain estimates and assumptions that we believe to be reasonable based on the information referred to above and similar sources, as well as our internal research, calculations and assumptions based on our analysis of such information and our knowledge of, and our experience to date in, our industries and markets. Market share data is subject to change and may be limited by the availability of raw data, the voluntary nature of the data gathering process and other limitations inherent in any statistical survey of market share data. In addition, customer preferences are subject to change. Accordingly, you are cautioned not to place undue reliance on such market share data or any other such estimates. While we believe such information is reliable, we cannot guarantee the accuracy or completeness of this information, and have we independently verified any third-party information and data from our internal research has not been verified by any independent source.

2

Operating Overview

Montrose Environmental at a Glance

• Unique, high growth environmental Media solutions company with a focus on ESG

excellence

• Large and growing addressable market

• Resilient revenue with repeat client base and diverse end markets

2,000+		70+		In the USA,
Employees		Offices		Canada,
				Europe &
				Australia

• Consistent record of organic growth and innovation, even during Covid-19 pandemic
• Consistent record of strategically and financially accretive acquisitions
• Strong cash flow profile and balance sheet

4

Highlights

• Solid quarterly results driven by industry tailwinds and organic growth
• Increased urgency to address climate change, a higher frequency of environmental crises and emerging contaminants provide substantive growth opportunities
• Organic growth and accretive acquisitions on pace to produce another year of +20% annual revenue growth
• Increases guidance for full year 2021
• Inaugural ESG report (published in July) highlights commitment to employees, clients, communities and shareholders - economic success driven by environmental solutions and ESG excellence

1. Adjusted EBITDA and Adjusted EBITDA margin are non-GAAP
   measures. Adjusted EBITDA adds back non-recurring expenses. Adjusted EBITDA margin represents Adjusted EBITDA as a percentage of revenue. See the appendix to this presentation for a discussion of these measures and a reconciliation of Adjusted EBITDA to the most directly comparable GAAP measure.

Q2 2021	1H 2021
Revenue	Revenue
+85%	+100%
to $136.2M	to $270.0M
Adj. EBITDA(1)	Adj. EBITDA(1)
+51%	+94%
to $21.0M	to $37.8M
Adj. EBITDA Margin(1)	Adj. EBITDA Margin(1)
15.4%	14.0%
of Revenue	of Revenue