Montrose Environmental : 4Q22 Earnings Call Presentation

Fourth Quarter &

Full Year 2022

Earnings Call

March 1, 2023

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. 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, 2022, 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, reconciliations for historical periods thereof to the most directly comparable GAAP measures and certain matters related to forward-lookingnon-GAAP information.

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.

© 2023 Montrose Environmental Group, Inc. Proprietary and Confidential.	2

Operating Overview

2022 Highlights

Full Year 2022

• Solid full year 2022 results primarily driven by strengthening client demand and broad-based organic growth
• Record customer revenue retention(1) increased to approximately 96% and cross-selling(1) revenues nearly doubled to 35% of total revenues
• Record organic revenue growth of 26% (excluding CTEH) helped mitigate the expected decline in CTEH COVID-19 revenues; Total organic revenue growth including the expected decline in CTEH COVID-19 revenues was (7)% YoY
• Most service lines grew organically with notable strength within PFAS water treatment, greenhouse gas measurement, and renewable energy solutions
• Acquisitions and investments funded with strong Adjusted Operating Cash Flow(2); Balance sheet remains strong
• 2023E outlook reflects strong momentum in core business and continued, elevated organic growth across most service lines

(1)	Customer revenue retention defined as the percentage of revenue excluding CTEH from customers in 2021 that recurred in
	2022. CTEH revenue is excluded from the calculation in light of episodic nature of emergency response work. Cross selling
	activity defined as the percentage of total revenue from customers purchasing two or more Montrose services within the same
	fiscal year.
(2)	Adjusted Operating Cash Flow is a non-GAAP measure and excludes the payment of acquisition-related contingent
	consideration of $19.5 million in 2022 and $15.6 million in 2021. Reported cash from operating activities was $20.6 million in
	2022 and $37.6 million in 2021. See the appendix to this presentation for a discussion of Adjusted Operating Cash Flow.
(3)	Consolidated Adjusted EBITDA, Adjusted Net Income (Loss) and Adjusted Net Income (Loss) Per Share are non-GAAP measures.
	See the appendix to this presentation for a discussion of these measures, including how they are calculated and the reasons
	why we believe they provide useful information to investors, and a reconciliation for historical periods to the most directly
	comparable GAAP measures.

Revenue

$544.4M

Organic Growth in Nearly

All Service Lines

Consolidated Adjusted

EBITDA(3)

$66.2M

12.2% of Revenue

Adj. Operating Cash Flow(2)

Full Year 2022

$40.1M

Operating Cash Flow Full Year 2022 of $20.6 Million

Adj. EPS(3)

$0.24

Adj. Net Income(3)

of $25.1 Million

Total Operating Segments

Adjusted EBITDA

$99.7M

18.3% of Revenue

Net Leverage(4)

1.3x

Low Leverage

Profile

(4) The Company's leverage ratio under its credit facility includes the impact of acquisition-related contingent earnout payments

that may become payable in cash.

© 2023 Montrose Environmental Group, Inc. Proprietary and Confidential.	4

Strong Record of Long-Term Growth

• Continued market share gains through (i) technology innovation & patent development and (ii) sales & marketing with a focus on integrated environmental solutions
• Consistent growth of cross-selling(1) activity to ~35% of revenue in 2022 and customer revenue retention(1) to 96% in 2022 are primary drivers of strong organic growth
• Continued strong momentum with 2020-2022 organic growth CAGR(2,3) of ~18%, excluding CTEH, compared to ~8% pre-IPO
• 2023E outlook at midpoint assumes double-digit organic growth (excluding CTEH)
• 2023E outlook at midpoint, including CTEH, assumes mid- single digit growth, despite decline in COVID-19 services
• 2023E outlook does not include future acquisitions; cadence of acquisitions is expected to increase in 2023 compared to 2022

Revenue

2020-2023E CAGR(2,3) (excluding CTEH): 29%

($ in Millions, Dec FYE)

	$546	$544	$550-600(4)
		$114	$75-95
	$232
$328			$475-
$82		$431	505
	$315
$246
2020	2021	2022	2023E

MEG Excluding CTEH

CTEH

1. Customer revenue retention defined as the percentage of revenue excluding CTEH from customers in 2021 that recurred in 2022. CTEH revenue is excluded from the calculation in light of episodic nature of emergency response work. Cross selling activity defined as the percentage of total revenue from customers purchasing two or more Montrose services within the same fiscal year.
2. CTEH excluded from CAGR calculations given that it was not owned for full year 2020.
3. Excludes discontinued service lines, which generated revenues of $17.1 million in 2020, $12.1 million in 2021, and $3.6 million in 2022.
4. Does not include any benefit from future acquisitions that have not yet been completed. In historical periods, revenues generated by businesses acquired during the year are included in revenue.

© 2023 Montrose Environmental Group, Inc. Proprietary and Confidential.	5