#1IRON MOUNTAIN INVESTOR PRESENTATION NOVEMBER 2023 IRON MOUNTAINⓇ Hunan ReROUPCHS Legal Accounting Finance Marketing Publicity Promotion Research lopment Engineering Manufacturing Planning H www Administration /Human Resource Legal /Accounting /Financo /Marketing Publicity 70207+ 3-156 4921 /Promotion /RegoadEN /BjotnooD /Dovelopment /Enginooring /Manufacturing /Planning#2FORWARD-LOOKING STATEMENTS We have made statements in this presentation that constitute "forward-looking statements" as that term is defined in the Private Securities Litigation Reform Act of 1995 and other securities laws. These forward-looking statements concern our current expectations regarding our future results from operations, economic performance, financial condition, goals, strategies, investment objectives, plans and achievements. These forward-looking statements are subject to various known and unknown risks, uncertainties and other factors, and you should not rely upon them except as statements of our present intentions and of our present expectations, which may or may not occur. When we use words such as "believes", "expects", "anticipates", "estimates", "plans", "intends", "pursue", "will" or similar expressions, we are making forward-looking statements. Although we believe that our forward-looking statements are based on reasonable assumptions, our expected results may not be achieved, and actual results may differ materially from our expectations. In addition, important factors that could cause actual results to differ from expectations include, among others: (i) our ability or inability to execute our strategic growth plan, including our ability to invest according to plan, grow our businesses (including through joint ventures), incorporate alternative technologies into our offerings, achieve satisfactory returns on new product offerings, continue our revenue management, expand and manage our global operations, complete acquisitions on satisfactory terms, integrate acquired companies efficiently and transition to more sustainable sources of energy; (ii) changes in customer preferences and demand for our storage and information management services, including as a result of the shift from paper and tape storage to alternative technologies that require less physical space; (iii) the impact of our distribution requirements on our ability to execute our business plan; (iv) the costs of complying with and our ability to comply with laws, regulations and customer requirements, including those relating to data privacy and cybersecurity issues, as well as fire and safety and environmental standards; (v) the impact of attacks on our internal information technology ("IT") systems, including the impact of such incidents on our reputation and ability to compete and any litigation or disputes that may arise in connection with such incidents; (vi) our ability to fund capital expenditures; (vii) our ability to remain qualified for taxation as a real estate investment trust for United States federal income tax purposes ("REIT"); (viii) changes in the political and economic environments in the countries in which we operate and changes in the global political climate; (ix) our ability to raise debt or equity capital and changes in the cost of our debt; (x) our ability to comply with our existing debt obligations and restrictions in our debt instruments; (xi) the impact of service interruptions or equipment damage and the cost of power on our data center operations; (xii) the cost or potential liabilities associated with real estate necessary for our business; (xiii) unexpected events, including those resulting from climate change or geopolitical events, could disrupt our operations and adversely affect our reputation and results of operations; (xiv) failures to implement and manage new IT systems; (xv) other trends in competitive or economic conditions affecting our financial condition or results of operations not presently contemplated; and (xvi) the other risks described in our periodic reports filed with the SEC, including under the caption "Risk Factors" in Part I, Item 1A of our Annual Report. Except as required by law, we undertake no obligation to update any forward-looking statements appearing in this presentation. Reconciliation of Non-GAAP Measures Throughout this presentation, Iron Mountain discusses (1) Adjusted EBITDA, (2) Adjusted EPS, and (3) AFFO. These measures do not conform to accounting principles generally accepted in the United States ("GAAP"). These non-GAAP measures are supplemental metrics designed to enhance our disclosure and to provide additional information that we believe to be important for investors to consider in addition to, but not as a substitute for, other measures of financial performance reported in accordance with GAAP, such as operating income, net income (loss) attributable to Iron Mountain Incorporated or cash flows from operating activities (as determined in accordance with GAAP). The reconciliation of these measures to the appropriate GAAP measure, as required by Regulation G under the Securities Exchange Act of 1934, as amended, and their definitions are included in the Supplemental Reporting Information. IRON MOUNTAIN IRM INVESTOR PRESENTATION 2#3TABLE OF CONTENTS COMPANY OVERVIEW OVERVIEW OF OUR BUSINESS UNITS 4 13 FINANCIAL OVERVIEW AND SUSTAINABILITY 19 APPENDIX IRON MOUNTAIN 27 IRM INVESTOR PRESENTATION 3#4COMPANY OVERVIEW IRON MOUNTAIN IRM INVESTOR PRESENTATION#5IRON MOUNTAIN SNAPSHOT (NYSE: IRM) Mountaineers ~26,000 Customers Served Countries Served 225,000+ 60 Global Presence ~97M Sq. Ft. | ~730M Cubic Ft. Global Physical Volume IRON MOUNTAIN Note: All figures as of 9/30/23 unless otherwise noted. Facilities ~1,400 2022 Revenue Breakdown Storage 59% 41% Service ~$5.1B Member of S&P 500 Nareit. IRM INVESTOR PRESENTATION 5#6OVERVIEW OF OUR BUSINESS UNITS Global RIM1 Data Center Asset Lifecycle Management (ALM) Crozier Fine Arts Comprehensive information management offerings spanning physical storage, digital solutions, and digital storage Data Center facilities for enterprise and hyperscale clients to protect mission-critical assets and ensure continued operation of IT infrastructure IT asset management solutions through entire asset lifecycle while protecting data, optimizing use, maximizing return on investment, and minimizing environmental impact Technical expertise in handling, installation, and storing of art to provide customers sustainable solutions IRON MOUNTAIN 1 Records and Information Management (RIM); includes physical and digital. IRM INVESTOR PRESENTATION 6#7OUR PURPOSE AND VALUES PURPOSE We protect and elevate the power of our customers' work VALUES 唯 of twi Act Own with Integrity Safety & Security Build Customer Value Take Ownership IRON MOUNTAINⓇ Promote Inclusion & Teamwork IRM INVESTOR PRESENTATION 7#8SUSTAINABLE COMPETITIVE ADVANTAGES Synergistic Global Business Long-tenured Customer Relationships with Institutional Expertise Cash-generative and Highly Profitable Model with Durable Revenue Stream Comprehensive Information Management and Data Storage Solutions Leader in Sustainability IRON MOUNTAINⓇ Mountaineer Talent and Operating Culture IRM INVESTOR PRESENTATION 8#9OUR NEAR-TERM GROWTH JOURNEY . Climb On! • Strong Global Leadership Positions in Multiple Businesses • World-class Operations $4.5B 2021 Revenue $4.2B 2019 Revenue 70 Years of Success Summit Growth Foundation IRON MOUNTAIN $5.1B 2022 Revenue $5.5B - $5.6B 2023E Revenue MATTERHORN: Accelerating Growth ~$7.3B 2026E Revenue IRM INVESTOR PRESENTATION 9#10PROJECT MATTERHORN OPERATING MODEL • Introduced at September 2022 Investor Event Shifting from product to solution sale through new global enterprise-wide commercial platform • Migrating execution from businesses to new global enterprise-wide operational platform Businesses benefitting from shared services and best practices Investing to support growth IRON MOUNTAIN GLOBAL COMMERCIAL Global RIM1 Data Center ALM² Crozier Fine Arts GLOBAL OPERATIONS 1 Records and Information Management (RIM); includes physical and digital. 2 Asset Lifecycle Management (ALM); comprised of three verticals: hyperscale, enterprise and OEM IRM INVESTOR PRESENTATION 10#11LARGE AND GROWING TOTAL ADDRESSABLE MARKET $10B 2015 IRON MOUNTAINⓇ $140B+ 2023 Expanded TAM Driven by Fast Growing Categories AAA DATA CENTER ASSET LIFECYCLE MANAGEMENT (ALM) DIGITAL SOLUTIONS Significant Opportunity to Further Scale and Capture Market Share Source: Management estimates. IRM INVESTOR PRESENTATION 11#12EXPERIENCED LEADERSHIP TEAM Bill Meaney 2013 President & CEO Barry Hytinen 2020 Mithu Bhargava 2023 Raymond Fox 2015 Edward Greene EVP & CFO EVP & GM, Digital Solutions EVP & Chief Risk Officer 2020 EVP & CHRO Mark Kidd 2003 EVP & GM Data Centers & ALM IRON MOUNTAINⓇ Peter Hwang 2023 EVP & GM, Data Centers Deborah Marson Greg McIntosh Arvind Subramanian 2009 EVP & GC and Secretary 2014 EVP & CCO 2023 EVP & MD JT Tomovcsik 1986 EVP & COO Seasoned and Skilled Management Team with Deep Industry Experience IRM INVESTOR PRESENTATION 12#13OVERVIEW OF OUR BUSINESS UNITS IRON MOUNTAIN IRM INVESTOR PRESENTATION#14GLOBAL RIM AT A GLANCE Records/Data Management O Global Digital Solutions Consumer Storage Transportation Services ► Integrated physical and digital information management offerings ► Trusted by ~95% of Fortune 1000 ▸ Over 225K customers spanning 60 countries ► Consistent ~98% customer retention ‣ Custodian of critical information for decades $ Revenue Management Core Services IRON MOUNTAINⓇ Support, Streamline, and Enhance Customer's Business Strategy and Operations IRM INVESTOR PRESENTATION 14#15DATA CENTER AT A GLANCE 0000 Smart Hands Data Center Installations & Builds O Data Center Migration Network Operations Center Portal & Support Serve 1,300+ customers including 5 of largest global hyperscalers Existing portfolio has capacity to nearly quadruple from current operations Global footprint - 21 markets, 24 data centers Leading sustainability efforts: data center platform matches 100% of consumption with renewable electricity procurement and benefits from low PUE One of the top 30 buyers of renewable energy among Fortune 1000 Offer Green Power Pass IRON Note: All figures as of 9/30/23 MOUNTAINⓇ Deepening Customer Relationships with Recurring Revenue Services IRM INVESTOR PRESENTATION 15#16DATA CENTER: GLOBALLY CONNECTED PLATFORM OF ~860 MEGAWATTS Includes ~415 Megawatts of Capacity to Sell To Be Sold Northern Virginia 52 Madrid 78 Phoenix 38 Chicago 36 Mumbai 54 Amsterdam 20 New Jersey 5 Frankfurt 1 All Other Operating 18 WW and Other Future Development 114 IRM Markets Operational Data Centers Data Center Markets Under Construction Sub-total: To Be Sold Under Contract, Leased Under Contract, Pre-leased ~415 207 239 Total ~860 IRON MOUNTAINⓇ Note: All figures as of 9/30/23#17ASSET LIFECYCLE MANAGEMENT AT A GLANCE Configuration Imaging Asset Tagging Decommissioning & Data Erasure Reclaiming Inventory Management & Deployment Remarketing ▸ Global footprint and trusted customer relationships ► Best-in-class data security and chain of custody ▸ Market leader in cloud/hyperscale decommissioning ► Strongly synergistic with core and data center businesses Recycling Unique Services Delivery Platform Developed on Scope, Capabilities, and Exclusive Built-for-Purpose Technology IRON MOUNTAINⓇ IRM INVESTOR PRESENTATION 17#18FINANCIAL OVERVIEW AND SUSTAINABILITY IRON MOUNTAIN IRM INVESTOR PRESENTATION#19STRONG OPERATING PERFORMANCE Revenue ($M) $4,492 $4,147 $5,500 - $5,600 $5,104 Adj. EBITDA¹ ($M) $1,635 $1,476 $1,940- $1,975 $1,827 $888 AFFO1 ($M) AFFO/Share1 $1,150 - $1,175 $1,110 $1,012 $3.91 - $4.00 $3.80 $3.48 $3.07 2020 2021 2022 2023E 2 2020 2021 2022 2023E 2 2020 2021 2022 2023E 2 2020 2021 2022 2023E 2 IRON MOUNTAIN 1 Non-GAAP measure, please see Appendix for reconciliation. 2 Iron Mountain financial guidance for 2023. IRM INVESTOR PRESENTATION 19#20UPDATE ON THIRD QUARTER 2023 Q3 ACCOMPLISHMENTS Record quarterly performance О Revenue of $1.4 billion O Adjusted EBITDA of $500 million O AFFO of $290 million O AFFO/Share of $0.99 Net income of $91 million Storage: Organic storage rental revenue growth of 10%, led by Global RIM at 8%, reflecting continued benefit of pricing combined with positive volume trends ALM: Consistent revenue performance and strengthening Enterprise bookings O Signed agreement to acquire Regency Technologies Data Center: Leased 65 megawatts of capacity in the quarter, for a total of 120 megawatts this year IRON MOUNTAIN® ($M, Except per Share Data) Three Months Ended 9/30/23 9/30/22 YOY % A Reported $ Constant Fx Storage Rental Revenue $859 $760 13% 12% Service Revenue $530 $527 1% Total Revenue $1,389 $1,287 8% 7% Net Income $91 $193 (53)% Reported EPS $0.31 $0.66 (53)% Adj. EPS $0.45 $0.48 (6)% Adj. EBITDA $500 $469 7% 6% Adj. EBITDA Margin 36.0% 36.5% -50 bps AFFO $290 $288 1% AFFO per Share $0.99 $0.98 1% IRM INVESTOR PRESENTATION 20#21UPDATE ON FULL YEAR 2022 FY22 ACCOMPLISHMENTS • Record full year performance ($M, Except per Share Data) Full Year YOY % A Revenue of $5.1B, up 14% YoY, or 17% excluding Fx impact 12/31/22 12/31/21 Reported $ Constant Fx Adjusted EBITDA of $1.8B, growth of 12% YoY, or 15% excluding Fx impact Storage Rental Revenue $3,034 $2,870 6% 9% Service Revenue $2,070 $1,621 28% 32% Total Revenue $5,104 $4,492 14% 17% • Net Income of $562M . AFFO of $1.1B, up 10% YoY ● AFFO/Share of $3.80, up 9% YoY Organic storage rental revenue growth of 8.9%, reflecting continued benefit of pricing combined with positive volume trends and data center growth · Leased 139 megawatts in the full year; exceeded 130 megawatt projection for 2022; expect to lease 80 megawatts or more in 2023 IRON MOUNTAIN® Net Income $562 $453 24% Reported EPS $1.90 $1.55 23% Adj. EPS $1.79 $1.51 19% Adj. EBITDA $1,827 $1,635 12% 15% Adj. EBITDA Margin 35.8% 36.4% (60) bps AFFO $1,110 $1,012 10% AFFO per Share $3.80 $3.48 9% IRM INVESTOR PRESENTATION 21#22CAPITAL ALLOCATION STRATEGY Investing to Support Growth Capital Return Prudent Leverage IRON MOUNTAINⓇ 1 As of 12/31/22, net debt was ~78% fixed rate and -22% floating rate. • Dividend policy: Target AFFO payout ratio of low to mid-60s With strong operating performance, we increased our dividend in Q4 2023 7533355533 Dividend Payout Ratio 81% 80% 2019 2020 71% 65% 2021 Net Lease Adjusted Leverage 2022 Leverage target: long-term net lease adjusted leverage ratio of 4.5x – 5.5x 5.7x 5.5x 5.3x 5.3x • No significant debt maturities until 2027 5.1x 4.5x Vast majority of debt is fixed rate¹ 2019 2020 2021 2022 IRM INVESTOR PRESENTATION 22#23SUSTAINABILITY IS IN OUR DNA: MILESTONES AND GOALS Achieved Significant Milestones 2017: Data Center reached 100% renewable electricity 2019: Surpassed science-based target six years early by reducing emissions by 52% from a 2016 baseline 2020: Exceeded women and BIPOC in leadership goals set in 2016 2021: Launched 20 new public ESG goals 2022: Implemented a global human rights policy ✓ 2022: Completed climate scenario analysis 2022: Increased our reporting coverage of waste and recycling data to cover 90% of global operations ✓ 2022: Expanded gender pay parity to cover all global operations IRON MOUNTAINⓇ GOALS Leadership Awards RE100 key collaborator NEGO Winner By 2025... • • Achieve 25% reduction of GHG emissions from Scope 1 & 2 energy sources from our 2019 baseline All new construction of multi-tenant data center facilities will be certified to BREEAM Green Building Standard By 2040... • Drive Circular Economy innovation by working • Achieve 90% renewable electricity coverage globally (maintain 100% coverage in Data Center) toward zero waste in our operations Achieve Net Zero GHG emissions goal, 10 years ahead of the Paris Climate Accord • Collectively volunteer 100,000 hours in our communities Commitments & Awards GRI SCIENCE BASED TARGETS DRIVING AMBITIOUS CORPORATE CLIMATE ACTION THE GLOBAL COMPACT WE SUPPORT CDP RE 100 By 2030... • All IRM data centers worldwide will be Climate Neutral • 100% of company cars and 50% of company van fleet to be fully electric IRM INVESTOR PRESENTATION 23#24SUSTAINABLE OFFERINGS: ENABLING CUSTOMERS TO BECOME MORE SUSTAINABLE THROUGH POSITIVE IMPACT PRODUCTS Global RIM Document Shredding and Recycling Data Center Renewable Energy- Powered Data Centers ALM Refurbishment and Recycling Crozier Fine Arts Sustainable Shipping Secure Shredding Securely destroy and recycle documents while providing a Green Report including data for customers to include in ESG reporting Data Centers and Green Power Pass 100% clean energy: Assist customers in claiming renewable energy credits (RECs) for use toward Net Zero goals Landfill Diversion GHG Emissions Secure IT Asset Disposal Help customers refurbish and recycle IT assets and provide an Environmental Benefits Report to quantify landfill diversion and GHG emissions avoided. MATERIAL ISSUES Landfill Diversion "e-waste" Reduction Sustainable Shipping Solutions that provide environmentally conscious and cost-saving opportunity for customers to minimize their environmental impact GHG Emissions IRON MOUNTAIN IRM INVESTOR PRESENTATION 24#25OUR DIVERSE BOARD OF DIRECTORS Skills Matrix Capital Allocation / Strategy Pamela Arway Non-executive Chairperson, Jennifer Allerton Iron Mountain; Former President of Former CIO, Roche Clarke Bailey Former CEO, EDCI Holdings Kent Dauten Chairman and Former Managing Director, Keystone Capital Monte Ford Principal Partner, CIOSE C-suite Leadership Japan/APAC/Australia, American Express Global Expertise Risk Management Board Leadership 80% Robin Matlock Former SVP & CMO, VMware Bill Meaney President & CEO Iron Mountain Wendy Murdock Former CPO MasterCard Walter Rakowich Former CEO, Prologis Ted Samuels Doyle Simons Former President, Former CEO Capital Guardian Trust Co. Weyerhaeuser Technology 80% Operations Experience 70% IRON Strong Expertise to Support Our Strategy and Value Creation MOUNTAINⓇ Independent Director 90% 90% 100% 100% IRM INVESTOR PRESENTATION 25#26APPENDIX Reconciliation Tables IRON MOUNTAIN IRM INVESTOR PRESENTATION#27Q3 2023 RECONCILIATION OF NET INCOME TO ADJUSTED EBITDA IRON MOUNTAIN Q3 2023 $91,391 Q3 2022 Net Income Add / (Deduct): Interest Expense, Net Provision (Benefit) for Income Taxes Depreciation and Amortization Acquisition and Integration Costs Restructuring and Other Transformation $192,931 152,801 121,767 9,912 23,934 198,757 175,077 9,909 5,554 38,861 3,382 (Gain) Loss on Disposal/Write-Down of PP&E, Net (Including Real Estate) (4,416) (14,170) Other (Income) Expense, Net, Excluding our Share of Losses (Gains) from our Unconsolidated Joint Ventures Stock-Based Compensation Expense (17,626) (56,226) 18,313 14,326 Our Share of Adjusted EBITDA Reconciling Items from our Unconsolidated Joint Ventures 2,060 2,859 Adjusted EBITDA $499,962 $469,434 IRM INVESTOR PRESENTATION 27#28Q3 2023 RECONCILIATION OF REPORTED EPS TO ADJUSTED EPS Q3 2023 Q3 2022 Reported EPS - Fully Diluted from Net Income (Loss) Attributable to Iron Mountain Incorporated $0.31 $0.66 Add / (Deduct): Acquisition and Integration Costs 0.03 0.02 Restructuring and Other Transformation 0.13 0.01 (Gain) Loss on Disposal/Write-Down of PP&E, Net (0.02) (0.05) Other (Income) Expense, Net, Excluding our Share of Losses (Gains) from our Unconsolidated Joint Ventures Stock-Based Compensation Expense (0.06) (0.19) 0.06 0.05 Non-Cash amortization related to derivative instruments 0.02 Tax Impact of Reconciling Items and Discrete Tax Items (1) (0.03) (0.01) Adjusted EPS - Fully Diluted from Net Income (Loss) Attributable to Iron Mountain Incorporated $0.45 $0.48 IRON MOUNTAINⓇ (1) The difference between our effective tax rates and our structural tax rate (or adjusted effective tax rates) for the three months ended September 30, 2023 and 2022 is primarily due to (i) the reconciling items above, which impact our reported net income (loss) before provision (benefit) for income taxes but have an insignificant impact on our reported provision (benefit) for income taxes and (ii) other discrete tax items. Our structural tax rate for purposes of the calculation of Adjusted EPS for the quarters and year to date ended September 30, 2023 and 2022 was 13.3% and 16.5%, respectively. The Tax Impact of Reconciling Items and Discrete Tax Items is calculated using the current quarter's estimate of the annual structural tax rate. This may result in the current period adjustment plus prior reported quarterly adjustments not summing to the year to date adjustment. IRM INVESTOR PRESENTATION 28#29Q3 2023 RECONCILIATION OF NET INCOME TO FFO & AFFO Q3 2023 $91,391 Q3 2022 $192,931 Net Income Add / (Deduct): Real Estate Depreciation (1) Loss (Gain) on Sale of Real Estate, Net of Tax Data Center Lease-Based Intangible Assets Amortization (2) 80,430 750 7,482 74,652 (15,666) 3,687 Our Share of FFO (Nareit) Reconciling Items from our Unconsolidated Joint Ventures 679 FFO (Nareit) $180,732 $255,604 Add / (Deduct): Acquisition and Integration Costs 9,909 5,554 Restructuring and Other Transformation 38,861 3,382 (Gain) Loss on Disposal/Write-Down of PP&E, Net (Excluding Real Estate) (5,116) 2,616 Other (income) expense, Net, Excluding our Share of Losses (Gains) from our Unconsolidated Joint Ventures (17,626) (56,226) Stock-Based Compensation Expense 18,313 14,326 Non-Cash amortization related to derivative instruments 5,270 Real Estate Financing Lease Depreciation 3,001 3,020 Tax Impact of Reconciling Items and Discrete Tax Items (3) (10,220) (5,184) Our Share of FFO (Normalized) Reconciling Items from our Unconsolidated Joint Ventures (44) FFO (Normalized) $223,080 223 $223,315 Add / (Deduct): Non-Real Estate Depreciation 49,500 36,458 Amortization Expense (4) 47,280 46,764 Amortization of Deferred Financing Costs 5,485 4,472 Revenue Reduction Associated with Amortization of Customer Inducements and Above- and Below-Market Leases 1,715 1,851 Non-Cash Rent Expense (Income) 6.119 5,522 Reconciliation to Normalized Cash Taxes (8,364) 7,366 Our Share of AFFO Reconciling Items from our Unconsolidated Joint Ventures Less: 182 1,193 Recurring Capital Expenditures AFFO Per Share Amounts (Fully Diluted Shares): FFO (Nareit) FFO (Normalized) AFFO Per Share IRON Weighted Average Common Shares Outstanding - Basic MOUNTAIN Weighted Average Common Shares Outstanding - Diluted 34,861 $290,136 38,972 $287,971 50.61 $0.87 $0.76 $0.76 $0.99 292,148 $0.98 290,937 294,269 292,552 (1) Includes depreciation expense related to owned real estate assets (land improvements, buildings, building improvements, leasehold improvements and racking), excluding depreciation related to real estate financing leases. (2) Includes amortization expense for Data Center In-Place Lease Intangible Assets and Data Center Tenant Relationship Intangible Assets. (3) Represents the tax impact of (i) the reconciling items above, which impact our reported net income (loss) before provision (benefit) for income taxes but have an insignificant impact on our reported provision (benefit) from income taxes and (ii) other discrete tax items. (4)) Includes customer and supplier relationship value, intake costs, acquisition of customer relationships and other intangibles. Excludes amortization of capitalized commissions. IRM INVESTOR PRESENTATION 29#30FY22 RECONCILIATION OF NET INCOME TO ADJUSTED EBITDA Full Year 2022 Full Year 2021 $562,149 $452,725 Net Income Add / (Deduct): Interest Expense, Net Provision (Benefit) for Income Taxes Depreciation and Amortization 488,014 417,961 69,489 176,290 727,595 680,422 Acquisition and Integration Costs 47,746 12,764 Restructuring and Other Transformation 41,933 206,426 (Gain) Loss on Disposal/Write-Down of PP&E, Net (Including Real Estate) (93,268) (172,041) Other (Income) Expense, Net, Excluding our Share of Losses (Gains) from our Unconsolidated Joint Ventures Stock-Based Compensation Expense (83,268) (205,746) 56,861 61,001 Our Share of Adjusted EBITDA Reconciling Items from our Unconsolidated Joint Ventures Adjusted EBITDA 9,806 $1,827,057 4,897 $1,634,699 IRON MOUNTAIN IRM INVESTOR PRESENTATION 30#31FY22 RECONCILIATION OF REPORTED EPS TO ADJUSTED EPS Reported EPS - Fully Diluted from Net Income (Loss) Attributable to Iron Mountain Incorporated Add / (Deduct): Full Year 2022 Full Year 2021 $1.90 $1.55 Acquisition and Integration Costs 0.16 0.04 Restructuring and Other Transformation 0.14 0.71 Amortization Related to the Write-Off of Certain Customer Relationship Intangible Assets 0.02 (Gain) Loss on Disposal/Write-Down of PP&E, Net (0.31) (0.59) Other (Income) Expense, Net, Excluding our Share of Losses (Gains) from our Unconsolidated Joint Ventures (0.28) (0.71) Stock-Based Compensation Expense 0.19 0.21 Non-Cash amortization related to derivative instruments 0.03 Tax Impact of Reconciling Items and Discrete Tax Items (1) (0.08) 0.28 Net Income Attributable to Noncontrolling Interests 0.02 0.01 Adjusted EPS - Fully Diluted from Net Income (Loss) Attributable to Iron Mountain Incorporated $1.79 $1.51 IRON MOUNTAINⓇ 1 The difference between our effective tax rates and our structural tax rate (or adjusted effective tax rates) for the years ended December 31, 2022 and 2021 is primarily due to (i) the reconciling items above, which impact our reported net income (loss) before provision (benefit) for income taxes but have an insignificant impact on our reported provision (benefit) for income taxes and (ii) other discrete tax items. Our structural tax rate for purposes of the calculation of Adjusted EPS for the years ended December 31, 2022 and 2021 was 15.2% and 17.7%, respectively. The Tax Impact of Reconciling Items and Discrete Tax Items is calculated using the current quarter's estimate of the annual structural tax rate for the full year. This may result in the current period adjustment plus prior reported quarterly adjustments not summing to the full year adjustment. IRM INVESTOR PRESENTATION 31#32FY22 RECONCILIATION OF NET INCOME TO FFO & AFFO Net Income Add / (Deduct): Real Estate Depreciation (1) (Gain) Loss on Sale of Real Estate, Net of Tax Data Center Lease-Based Intangible Assets Amortization (2) FFO (Nareit) Add / (Deduct): Acquisition and Integration Costs Restructuring and Other Transformation Full Year 2022 $562,149 Full Year 2021 $452,725 307,895 307,717 (94,059) (142,892) 16,955 42,333 $792,940 $659,883 47,748 12,784 41,933 206,426 Loss (Gain) on Disposal Write-Down of PP&E, Net (Excluding Real Estate) 1,584 (3,751) Other (Income) Expense, Net, Excluding our Share of Losses (Gains) from our Unconsolidated Joint Ventures (83,268) (205,748) Stock-Based Compensation Expense 56,861 61,001 Non-Cash amortization related to derivative instruments 9,100 Real Estate Financing Lease Depreciation 13,197 14,835 Tax Impact of Reconciling Items and Discrete Tax Items (3) (25,190) 56,822 Our Share of FFO (Normalized) Reconciling Items from our Unconsolidated Joint Ventures 2,874 (38) FFO (Normalized) $857,757 $801,996 Add/(Deduct): Non-Real Estate Depreciation 157,892 142,720 Amortization Expense (4) 191,043 142,278 Amortization of Deferred Financing Costs 18,044 16,548 Revenue Reduction Associated with Amortization of Customer Inducements and Above- and Below-Market Lease Non-Cash Rent Expense (Income) 8,119 8,852 19,056 Reconciliation to Normalized Cash Taxes Our Share of AFFO Reconciling Items from our Unconsolidated Joint Ventures (3,822) 4,135 15,258 27,801 4,849 Less: Recurring Capital Expenditures AFFO 142,498 $1,109,930 148,201 $1,011,899 Per Share Amounts (Fully Diluted Shares): FFO (Nareit) FFO (Normalized) $2.71 $2.93 $2.27 $2.76 IRON AFFO Per Share $3.80 $3.48 Weighted Average Common Shares Outstanding - Basic 290,812 289,457 MOUNTAINⓇ Weighted Average Common Shares Outstanding - Diluted 292,444 290,975 1 Includes depreciation expense related to owned real estate assets (land improvements, buildings, building improvements, leasehold of improvements and racking), excluding depreciation related to real estate financing leases. 2 Includes amortization expense for Data Center In-Place Lease Intangible Assets and Data Center Tenant Relationship Intangible Assets. ³ Represents the tax impact of (i) the reconciling items above, which impact our reported net income (loss) before provision (benefit) for income taxes and (ii) other discrete tax items. 4 Includes Customer and Supplier Relationship Value, intake costs, acquisition of customer relationships and other intangibles. Excludes amortization of capitalized commissions. IRM INVESTOR PRESENTATION 32#33APPENDIX Investor Relations Contact Information IRON MOUNTAIN IRM INVESTOR PRESENTATION#34INVESTOR RELATIONS CONTACT INFORMATION GILLIAN TILTMAN SVP and Head of Investor Relations E: Gillian. [email protected] O: (617) 236-4881 IRON MOUNTAIN ERIKA CRABTREE Manager Investor Relations E: [email protected] O: (617) 535-2845 IRM INVESTOR PRESENTATION 34