The Preferred Provider of Mission Critical Real Estate Solutions

Corporate Office Properties Trust

Nareit REITworld: Virtual Annual

ConferenceNovember 17-19, 2020

2

Table of ContentsSafe HarborUnless otherwise noted, information in this presentation represents the Company’sconsolidated portfolio as of or for the quarter ended September 30, 2020.

This presentation may contain “forward-looking” statements, as defined inSection 27A of the Securities Act of 1933 and Section 21E of theSecurities Exchange Act of 1934, that are based on the Company’scurrent expectations, estimates and projections about future events andfinancial trends affecting the Company. These statements may include,without limitation, statements regarding: our belief that we are well-positioned to maintain relative normal operations through the COVID-19crisis; our expectations as to renewal leasing, rent relief requests,development leasing and development projects; our liquidity situation; andour dividend. Forward-looking statements are inherently subject to risksand uncertainties, many of which the Company cannot predict withaccuracy and some of which the Company might not even anticipate.Although the Company believes that expectations, estimates andprojections reflected in such forward-looking statements are based onreasonable assumptions at the time made, the Company can give noassurance that these expectations, estimates and projections will beachieved. Future events and actual results may differ materially fromthose discussed in the forward-looking statements and the Companyundertakes no obligation to update or supplement any forward-lookingstatements.

The areas of risk that may affect these expectations, estimates andprojections include, but are not limited to, those risks described in Item 1Aof the Company’s Annual Report on Form 10-K for the year endedDecember 31, 2019 and subsequent Quarterly Reports on Form 10-Q.

I. Overview…………...…............................Page 3

II. Factors Supporting Growth……………Page 6

III. Minimal Impact from COVID-19……...Page 17

IV. 2020 Guidance………....………..……...Page 25

V. Appendices……………………………...Page 29

A. Definitions & GlossaryB. Reconciliations

3

I. Results for 4Q & FY 2018I. Overview

100 Secured Gateway, Huntsville, AL

4

Mission Critical LocationsCOPT owns 167 buildings1 in Defense/IT Locations adjacent or in close proximity to proven, growing U.S. Government Defense Installations

State#

BldgsCore

SF2 Demand Driver

MD 101 8,996 Fort Meade, NAVAIR

VA 253 4,4953 Cloud Computing, NAP for MAE-East

19 2,193

Intelligence Community, NGA, NRO, FBI Cyber &

Other

TX 7 953Lackland AFB,

Air Force & Other Cyber

AL 13 1,278 Redstone Arsenal

DC 2 358 Washington Navy Yard, NAVSEA

167 18,273

1. Excludes seven Regional Office buildings and two buildings in our Other segment. 2. In thousands.3. Includes 100% of the SF in 17 data center shells that are owned through unconsolidated joint ventures at October 30, 2020.

5

COPT Virtually Unaffected by ShutdownsDurable Revenues;

Rent Collections Minimally Impacted

› Rent relief granted totals <1.0% of ARR1

› Extremely strong rent collections2:2Q20 – 99.7% (100% net)3Q20 – 99.6% (100% net)

October3 – 99.4% (99.9% net)November3 – 98.2% (98.7% net)

1. Annualized rental revenue (“ARR”).2. Net = total monthly billings adjusted to exclude rent relief granted.3. Reflects rents collected through November 12th.

Resilient Operations› 1Q, 2Q & 3Q20 results beat

guidance› All office & data centers open

& functioning› Majority of COPT tenants

deemed essentialDividend

Well-Covered

Strong Balance Sheet with Ample Liquidity

Leasing:› Developments Unaffected› Renewals at Record Levels› Vacancy Leasing Tempered

by Shutdowns; Now Rebuilding

Development Projects On-Track for

Timely Deliveries

6

I. Results for 4Q & FY 2018

6708 Alexander Bell Drive, Columbia, MD

II. Factors Supporting Growth

7

Healthy DOD Spending Levels» FY 2015–FY 2020, DOD’s Base Budget has grown at a compound annual rate of 5%» Strong bi-partisan support to fund defense:

» HASC voted in favor of FY 2021 NDAA 295-to-125; SASC voted 86-to-14

» As expected, Congress passed a continuing resolution on the FY 2021 budget through December 11, 2020

DOD’s Discretionary Budget Authority (“Base Budget”)*

Current dollars, in billions. Sources: Historical data through FY 2016 are pulled from Tables 1-9 and 2-1 of the National Defense Budget Estimates ("Green Books") for FY 2017 or earlier; data for FY 2017 through FY 2019 are pulled from Tables 1-2 and 2-1 of the FY 2020 Green Book; Capital Alpha Partners; COPT’s IR Department. † DOD base budget (051) numbers exclude funding for overseas contingency operations ("OCO"), Atomic Energy Defense Activities (053), Other Defense-Related Activities (054),

and mandatory spending. * FY 2017 includes $8.25 billion of "OCO for base budget purposes." Source: CRS report on the final authorizations.** FY 2018 includes $5.8 billion of supplemental authorizations for Missile Defense.‡ Estimated, using the 2020 DOD Appropriations Act and the 2020 Military Construction, Veterans Affairs, and Related Agencies Appropriations Act.

8

Mandate to Restore & Fund U.S. Military» A 2018 Pentagon Study reported that the DOD funding deficit created by the

Budget Control Act of 2011 and the multi-year failure to provide timely appropriations had eroded U.S. Military power “to a dangerous degree,” and provided the imperative to correct it

Prior Spending Deficit in Base Budget (050)

Source: National Defense Strategy Commission’s Providing for the Common Defense (2018):https://www.usip.org/publications/2018/11/providing-common-defense

9

Growth from Development Leasing

* As of October 29, 2020. Note: COPT’s Development Leasing Pipeline formerly was called its Shadow Development Pipeline.

Development Leasing» After record year in 2019, demand for new facilities remains strong

» Major lease executions to-date include three defense contractor build-to-suits and a large U.S. Government lease at Redstone Gateway

» Our Development Leasing Pipeline of 2.4 million SF*supports future growth and our goal of executing 1 million SF of development leasing in 2020

Robust Development Leasing Pipeline bodes well for future development leasing & NOI growth

0

500,000

1,000,000

1,500,000

2,000,000

Actual SF Forecasted Initial Goal

10

Highly Leased Developments Drive NOI Growth» Between 2013–3Q20,

we placed 7.8 million SF into service that, on average, were 96% leased

» This includes 1.2 million SF placed in service during 2020 that were 99% leased

» During 4Q20, we expect to place another 540,000 SF in service that are 100% leased, contributing to FFO growth into 2021/2022

Square Feet of Development Placed Into Service*

* As of September 30, 2020.

0%

20%

40%

60%

80%

100%

-

200,000

400,000

600,000

800,000

1,000,000

1,200,000

1,400,000

1,600,000

1,800,000

2,000,000

2013 2014 2015 2016 2017 2018 2019 2020 E

SF PIS Forecasted % Leased

973,000 SF PIS annually, 96% leased

11

Vacancy Leasing Tempered by Shutdowns» Strong Vacancy Leasing of 143,000 SF in 1Q20 was 13% higher than 1Q19 results» 2Q & 3Q20 Vacancy Leasing volumes totaling 131,000 SF were light due to pandemic

shutdowns affecting tenant decisions and brokerage firms» Leasing Activity Ratio† is rebuilding; expect solid volume in 4Q20 and momentum going

into 2021

† Leasing Activity Ratio = total vacant SF divided by total prospects* Percent occupied & leased statistics are for COPT’s core portfolio.

Vacancy Leasing in COPT’s Operating Portfolio*

50%

55%

60%

65%

70%

75%

80%

85%

90%

95%

100%

0

50

100

150

200

250

300

350

Core

Por

tfolio

% L

ease

d an

d O

ccup

ied

Squa

re F

eet o

f Vac

ancy

Lea

sed

(000

s)

Defense/IT Regional Office* % Leased % Occ

2016 2017 2018 2019 2020

12

Tenant co-investment creates “stickiness” and supports COPT’s sector-leading tenant retention rates and low renewal CapX

Strong Tenant Retention

» Proven track record of strong tenant retention rates, averaging:

» 73% between 2010−2019

» 78% between 2016−2019

» In April, increased 2020 tenant retention guidance to 75–80% and again in July, to new range of 80–85%

» FFO & AFFO benefits of high renewal rates more than offset impact of cash rent roll downs

Source: Company Supplemental Information Reports* 20-year record renewal rate of 80% was established in 2017.

COPT’s Renewal Rates Since 2000

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

» Expect renewal rate of 80–85% in 2020 to set 20-year record*

13

Low Leasing CapX on Renewals» During 2019, we maintained our track record of low leasing costs / SF / year

on renewing leases» During the first nine months of 2020, our 84% renewal rate exceeded

internal expectations and our CapX / SF / year of term was only $2.05

2019 Leasing CapX per SF per Year of Term* ─ Renewing Leases

* Average for the trailing four quarters ended December 31, 2019a. Office portfolio only.The following office REITs do not disclose enough information to be included in this analysis: BDN, DEA, FSP, HIW, KRC, PGRE

$9.52

$7.54

$7.29

$6.24

$5.91

$5.41

$5.38

$5.10

$4.88

$4.82

$2.53

$2.25

$0.00 $1.00 $2.00 $3.00 $4.00 $5.00 $6.00 $7.00 $8.00 $9.00 $10.00

BXP

CXP

JBGS

CUZ

PDM

CLI

WRE (a)

DEI

SLG (a)

HPP

OFC

OPI

14

Large Leases Update

» 2020 Large Leases» 1H20 renewals (1.1 million SF) included one

contractor and one USG lease

» As expected, tenant at 6721 Columbia Gateway Drive did not renew on 4/30 One floor (31,000 SF) already back-filled

» Two USG renewals in San Antonio, TX are in process

» 2021–Zero Large Lease Exposure» During 2020, we executed early renewals for all

four Large Leases previously scheduled to expire in 2021:

Boeing executed early renewals on all three full-building leases at Redstone Gateway and Booz Allen Hamilton executed an early renewal on its 130,000 SF lease at The National Business Park

Continued Strong Retention of Large Tenants*

2020 Large Leases

# Leases SF

Actual or Expected

% Renewal

USG:▫ Executed▫ In Process

12

125,000250,000

100%100%

Contractors:▫ Executed▫ Non-Renewal

11

157,000131,000

100%0%

Commercial -- -- --

5 663,000 80%

2021 Large Leases

# Leases SF

Actual % Renewal

USG -- -- --

Contractors 4 493,000 100%

Commercial -- -- --

4 493,000 100%

* Large lease is defined as 100,000 SF or more.

15

Manageable Future Lease Expirations» Concentration of expirations at mission critical Defense/IT Locations

mitigates rollover risk (Barriers to Exit)» As of September 30, 2020, less than 7% of SF and only 7.7% of core

ARR scheduled to expire in 2021

Based on the Company's core portfolio.2017─2019 SF represent the total expiring SF for those time periods, as reported in the 4Q supplemental packages.The percentages above the bars are the percent of leased SF scheduled to expire; the dollar amounts in the boxes are the associated annualized rental revenues.† Four large leases with defense contractors scheduled to expire in 2021 early renewed during 3Q20 (493,000 total SF).

Scheduled Office Lease Maturities

0

500

1,000

1,500

2,000

2,500

3,000

3,500

2017 A 2018 A 2019 A 2020 2021 2022 2023 2024

Squa

re F

eet E

xpiri

ng (

000s

)

SF Renewed Defense/IT SF Regional Office SF

6.8%

11.4%

9.9%

13.5% 2.1%

$17.3

$41.2

$68.5

$65.0

$70.1

†

16

Strong Balance Sheet & Liquidity» 2020 guidance now includes

raising ~$165 million of equity in 4Q through selling joint venture interests; reduces Debt/EBITDA to 6.2x–6.4x by year-end Larger sale lowers risk to future

equity funding and maintains strong balance sheet

Less than 1-cent dilution to internal 2021 forecast

» Operating at conservative leverage levels

» $693 million of liquidity** to complete the remaining $241 million of development commitments

* The Company launched its Strategic Reallocation Plan (“SRP”) in April 2011 and completed its programmatic selling in October 2017.** Excludes approximately $84 million of equity proceeds the Company expects to raise from a secured Blackstone joint venture in 4Q20.† Net debt to in-place adjusted EBITDA ratio.†† Net debt plus preferred equity to in-place adjusted EBITDA ratio.

Current Status Fitch Moody’s S&P

Rating BBB- Baa3 BBB-

Outlook Stable Stable Stable

4.0 x

5.0 x

6.0 x

7.0 x

8.0 x

9.0 x

10.0 x

11.0 x

Debt/EBITDA† (D + P)/EBITDA††

7.0 x

7.7 x

8.3 x

9.2 x

9.8 x

9.0 x

6.3 x

8.4 x

7.1 x

6.8 x

6.2 x

6.5 x

7.2 x

5.7 x

6.1 x6.0 x ~ 6.0x6.1 x

6.8 x

Maintaining Our Strong Balance Sheet

17

I. Results for 4Q & FY 2018III. Minimal Impact from COVID-19

Rendering of 4600 River Road, College Park, MD

18

COPT Virtually Unaffected by ShutdownsDurable Revenues;

Rent Collections Minimally Impacted

› Rent relief granted totals <1.0% of ARR1

› Extremely strong rent collections2:2Q20 – 99.7% (100% net)3Q20 – 99.6% (100% net)

October3 – 99.4% (99.9% net)November3 – 98.2% (98.7% net)

1. Annualized rental revenue (“ARR”).2. Net = total monthly billings adjusted to exclude rent relief granted.3. Reflects rents collected through November 12th.

Resilient Operations› 1Q, 2Q & 3Q20 results beat

guidance› All office & data centers open

& functioning› Majority of COPT tenants

deemed essentialDividend

Well-Covered

Strong Balance Sheet with Ample Liquidity

Leasing:› Developments Unaffected› Renewals at Record Levels› Vacancy Leasing Tempered

by Shutdowns; Now Rebuilding

Development Projects On-Track for

Timely Deliveries

19

1Q20 2Q20 3Q20Guidance Actual Guidance Actual Guidance Actual

FFOPS* $0.47 – $0.49 $0.51 $0.48 – $0.50 $0.51 $0.51 – $0.53 $0.54

Same-Property:

Occupancy 91.5% – 92.5% 92.7% 91% – 92% 92.3% 92 – 93% 92.5%

Cash NOI Growth -- 5.0% (3%) – (1.5%) 1.7% (1%) – 0% (0.2%)

Tenant Retention** 70% – 75% 89% 75% – 80% 76% in 2Q

81% for 1H 80 – 85%** 89.0% in 3Q84.3% YTD†

Development Spend -- ~$100 mm -- ~$100 mm -- ~$100 mm

Development Leasing Achieved:

1Q

2Q

3Q

Total to-date

‡ -- ‡

‡

--

276,000 SF

‡

‡

‡

--

276,000 SF

244,000 SF

520,000 SF

Nine-Month Results

* FFOPS = diluted funds from operations per share, as adjusted for comparability.** Tenant retention guidance was for the full year and as of April 30, 2020. Effective July 30, management increased

this range for the full year to 80%–85%.‡ The Company’s goal for 2020 is to execute 1 million SF of development leasing.

COPT has outperformed throughout pandemic

20

Collections Update

» Rent relief granted to-date totals ~0.9% of ARR » 0.2% of ARR in abatements, 0.4% in deferred rent, and 0.3% in rent reserves

and write-offs of uncollectible rents» No relief granted to U.S. Government tenants or major defense contractors» Most relief granted to food/amenity tenants in our office parks

» Rent collections minimally impacted by shutdowns:

Total Tenant Rent Relief Impact <1.0% of ARR

* Net = total monthly billings adjusted to exclude rent relief granted.† October data reflects rents collected through November 12th.

Collections

Month Gross Net*

2Q20 99.7% 100%

3Q20 99.6% 100%

October† 99.4% 99.9%

November† 98.2% 98.7%

21

Vacancy Leasing Update

» Strong achievement through April; 1Q20 volume exceeded 1Q19 by 13%

» Tenant broker shutdowns late March through late June precluded new showings» 2Q and 3Q20 volumes of 70,000 SF and 61,000 SF, respectively, were softer than original

forecast» Vacancy Leasing activity declined during the shutdowns, recovered to pre-pandemic levels

during September, and points to solid future leasing volumes

» Interest savings from senior notes tender offer and new issuance in September provide cushion to absorb impact of Vacancy Leasing delays on 2021 results

Solid Demand; Timing Less Certain

22

Development Leasing Update

» Nearly all discussions & negotiations commenced before COVID-19 have been executed or continue to advance

» Expected to meet or surpass goal of executing 1 million SF of Development Leasing in 2020» 520,000 SF of development leasing completed in 2020* includes: 3 defense contractor build-to-suits totaling 260,000 SF A large U.S. Government lease at 100 Secured Gateway 3 expansions of existing data center shells totaling 42,000 SF ~35% of 2020 development leasing has been with the U.S. Government

» Pursuing 2.4† million SF of opportunities in Development Leasing Pipeline

Largely Unaffected by Shutdowns and Restrictions

* Development leasing to-date, as of October 7, 2020.† As of October 29, 2020.

23

Balance Sheet

» We invested approximately $300 million in developments during the first nine months of 2020, leaving $50–$75 million to fund during 4Q20

» $693 million of liquidity as follows:

» A second JV transaction expected to close before year-end is on-track to generate an additional $84 million of equity proceeds

Ample liquidity to bridge an extended crisis

Dollars are in millions.* At September 30, 2020.

Cash on-hand* $11.5

Capacity on 2100 L Street construction loan* 37.4

Line of credit availability* 743.0

– October 19th redemption of 2021 Notes (180.0)

+ October 30th JV with Blackstone 81.0

Liquidity* $692.9

24

Dividend is Well-Covered

» Our $0.275/share quarterly dividend ($1.10/share annualized) is well-covered by operations

» Solid AFFO Payout Ratio:» 2020 plan incorporates a dividend/AFFO payout ratio of 65–70%, leaving

30–35% to invest in development pipeline

» Attractive 4.2% yield*

* As of the closing price on November 16, 2020.

25

I. Results for 4Q & FY 2018

8000 Rideout Road, Huntsville, AL

IV. 2020 Updated Guidance

26

2020 Guidance Highlights» On October 29, we increased the mid-point of full year FFO per

share* guidance by 2-cents, to $2.09» New mid-point represents 3% growth 2019 and is 1-cent higher than original

guidance

» Same-property:» Cash NOI to increase 1–1.5% for the full year

» Occupancy of 92–92.5% at year-end reflects impact of removing eight, 100% occupied data centers shells from the same-property pool in 4Q20, impacting year-end occupancy by approximately 60 basis points

» Invest $350–$375 million in developments throughout the year

» Place 1.75 million SF of developments into service that we expect to be fully leased » Includes the 1.2 million SF placed into service during first nine months of the year

* FFOPS, as adjusted for comparability.

27

2020 Guidance–Summary of AssumptionsUpdated Full Year 2020

Guidance 4Q20 Guidance

Diluted EPS $0.77 – $0.79 $0.63 – $0.65FFOPS1 $2.08 – $2.10 $0.52 – $0.54

Portfolio Metrics

Same-Property:» Cash NOI Growth» Occupancy (End of Period) – Pre-JV’s» Occupancy (End of Period) – Post-JV’s

1.0% – 1.5%92.5% – 93%92% – 92.5%

(2%) – 0%92.5% – 93%92% – 92.5%

Diluted AFFO Payout Ratio 65% – 70% *

Leasing

Expirations2 397,000 SF (3.2%) remaining 397,000 SF (3.2%)

Tenant Retention 80% – 85% *

Change in Cash Rents (2.5%) – (1.5%) *

Investment Activity ($mm)

Development $350 – $375 million $50 – $75 million

Acquisitions N/A N/A

Dispositions (Equity) $165 million3 $165 million3

1. FFOPS, as adjusted for comparability. Nareit FFOPS is forecasted to be $1.44–$1.46 and includes a 10-cent allocation to noncontrolling interests and a 54-cent loss on derivative financial instruments and the early extinguishment of debt.

2. SF expiring, plus the percent of core annualized rental revenues in parenthesis. 3. Equity proceeds the Company expects to raise from selling JV interests in two wholly-owned data center shells and six

others currently owned in another joint venture.* Incorporated in full-year guidance.

28

U.S. Government moves deliberately & slowly – and is

essential

COVID-19 pandemic’s

duration unknown;

unforeseen impacts possible

Healthy defense spending

environment & 12–18 month

demand tail support new leasing opportunities

› Occupancy gains

› New development

DOD Budget:› Prompt Payment Act ensures

U.S. Government pays rent, even during federal shutdowns

› Continuing Resolutions in any budget year may delay lease executions on contract contingent deals

Lease-up 310 NBP (135,500 SF

in 4 floors)

Modest equity raise included in 2020 plan

› Expect to raise ~$84 million of equity proceeds during 4Q20 by selling JV interests in data shells

› Debt/EBITDA ratio of 6.2x–6.4x at year-end

Reminders Risks Opportunities

Positioned for very healthy FFO growth of 3–6% in

2021

Ultimate timing of lease executions & commencements

DC-6 › 11.25 MW anchor

tenant renewal in final negotiations

29

V. AppendicesA. Definitions & Glossary

B. Reconciliations

30

A. Definitions & Glossary» Acquisition costs – transaction costs expensed in connection with executed or anticipated acquisitions of operating

properties.» Adjusted Book – total assets presented on our consolidated balance sheet, net of lease liabilities associated with

property right-of-use assets, and excluding the effect of cash and cash equivalents, accumulated depreciation on realestate properties, accumulated amortization of intangible assets on real estate acquisitions, accumulated amortization ofdeferred leasing costs, disposed properties included in assets held for sale, unconsolidated real estate joint venturescash and cash equivalents, liabilities, and accumulated depreciation and amortization (of real estate intangibles anddeferred leasing costs) allocable to our ownership interest in the joint ventures and the effect of properties serving ascollateral for debt in default that we extinguished (or intend to extinguish) via conveyance of such properties.

» Adjusted EBITDA – net income (loss) adjusted for the effects of interest expense, depreciation and amortization, gainon sales and impairment losses of real estate, gain or loss on early extinguishment of debt, net gain (loss) on otherinvestments, credit loss expense or recoveries, operating property acquisition costs, gain (loss) on interest ratederivatives, income taxes, business development expenses, demolition costs on redevelopment and nonrecurringimprovements, executive transition costs, certain other expenses that we believe are not closely correlated with ouroperating performance, and excluding the effect of properties that served as collateral for debt in default that weextinguished via conveyance of such properties. Adjusted EBITDA also includes adjustments to net income for theeffects of the items noted above pertaining to unconsolidated real estate JVs that were allocable to our ownershipinterest in the JV.

» Annualized Rental Revenue – the monthly contractual base rent as of the reporting date multiplied by 12, plus theestimated annualized expense reimbursements under existing leases for occupied space. With regard to propertiesowned through unconsolidated real estate joint ventures, we include the portion of Annualized Rental Revenue allocableto COPT’s ownership interest.

» ATFP – Anti-terrorism force protection.» Baltimore/Washington Region (or B/W Region) – includes counties that comprise the Fort Meade/Baltimore

Washington Corridor. As of September 30, 2020, 88 of COPT’s properties were located within this defined region. Pleaserefer to page 11 of COPT’s Supplemental Information package dated September 30, 2020 for additional detail.

31

A. Definitions & Glossary» Basic FFO available to common share and common unit holders (“Basic FFO”) – FFO adjusted to subtract

(1) preferred share dividends, (2) income attributable to non-controlling interests through ownership of preferred units inCorporate Office Properties, L.P. (the “Operating Partnership”) or interests in other consolidated entities not owned byus, (3) depreciation and amortization allocable to non-controlling interests in other consolidated entities, (4) Basic FFOallocable to share-based compensation awards, and (5) issuance costs associated with redeemed preferredshares. With these adjustments, Basic FFO represents FFO available to common shareholders and holders of commonunits in the Operating Partnership (“common units”). Common units are substantially similar to our common shares ofbeneficial interest (“common shares”) and are exchangeable into common shares, subject to certain conditions.

» BRAC – Base Realignment and Closure Commission of the United States Congress, the most recent of whichCongress established in 2005 to ensure the integrity of the base closure and realignment process. The Commissionprovided an objective, non-partisan, and independent review and analysis of the list of military installationrecommendations issued by the Department of Defense (“DOD”) on May 13, 2005. The Commission's mission was toassess whether the DOD recommendations substantially deviated from the Congressional criteria used to evaluate eachmilitary base. While giving priority to the criteria of military value, the Commission took into account the human impact ofthe base closures and considered the possible economic, environmental, and other effects on the surroundingcommunities.

» C4ISR – Command, Control, Communications, Computers, Intelligence, Surveillance &Reconnaissance» Cash net operating income (“Cash NOI”) – NOI from real estate operations adjusted to eliminate the effects of:

straight-line rental adjustments, amortization of tenant incentives, amortization of intangibles and other assets includedin FFO and NOI, lease termination fees from tenants to terminate their lease obligations prior to the end of the agreedupon lease terms, and rental revenue recognized under GAAP resulting from landlord assets and lease incentivesfunded by tenants. Cash NOI also includes adjustments to NOI from real estate operations for the effects of the itemsnoted above pertaining to unconsolidated real estate JVs that were allocable to our ownership interest in the JVs. UnderGAAP, rental revenue is recognized evenly over the term of tenant leases (through straight-line rental adjustments andamortization of tenant incentives), which, given the long term nature of our leases, does not align with the economics ofwhen tenant payments are due to us under the arrangements. Also under GAAP, when a property is acquired, weallocate the acquisition to certain intangible components, which are then amortized into NOI over their estimated lives,even though the resulting revenue adjustments are not reflective of our lease economics. In addition, revenue fromlease termination fees and tenant-funded landlord improvements, absent an adjustment from us, would result in largeone-time lump sum amounts in Cash NOI that we do not believe are reflective of a property’s long-term value.

32

A. Definitions & Glossary» Core Portfolio – Defense/IT Locations and Regional Office properties.» Debt/Total Market Capitalization – gross debt, divided by our total market capitalization.» Defense/IT Locations – properties in locations that support the United States Government and its contractors, most of

whom are engaged in national security, defense, and information technology (“IT”) related activities servicing what webelieve are growing, durable priority missions.

» Development profit or yield – calculated as cash NOI divided by the estimated total investment, before the impact ofcumulative real estate impairment losses.

» Diluted adjusted funds from operations available to common share and common unit holders (“Diluted AFFO”) –Diluted FFO, as adjusted for comparability, adjusted for the following: (1) the elimination of the effect of (a) noncash rentalrevenues and property operating expenses (comprised of straight-line rental adjustments, which includes the amortizationof recurring tenant incentives, and amortization of acquisition intangibles included in FFO and NOI, both of which aredescribed under “Cash NOI” above), (b) share-based compensation, net of amounts capitalized, (c) amortization ofdeferred financing costs, (d) amortization of debt discounts and premiums and (e) amortization of settlements of debthedges; and (2) replacement capital expenditures (defined below). Diluted AFFO also includes adjustments to DilutedFFO, as adjusted for comparability for the effects of the items noted above pertaining to unconsolidated real estate JVsthat were allocable to our ownership interest in the JVs.

» Diluted FFO available to common share and common unit holders (“Diluted FFO”) – Basic FFO adjusted to addback any changes in Basic FFO that would result from the assumed conversion of securities that are convertible orexchangeable into common shares. The computation of Diluted FFO assumes the conversion of common units but doesnot assume the conversion of other securities that are convertible into common shares if the conversion of thosesecurities would increase Diluted FFO per share in a given period.

» Diluted FFO available to common share and common unit holders, as adjusted for comparability (“Diluted FFO,as adjusted for comparability”) – Diluted FFO or FFO adjusted to exclude: operating property acquisition costs; gain orloss on early extinguishment of debt; FFO associated with properties that secured non-recourse debt on which wedefaulted and, subsequently, extinguished via conveyance of such properties (including property NOI, interest expenseand gains on debt extinguishment); loss on interest rate derivatives; demolition costs on redevelopment and nonrecurringimprovements; executive transition costs; accounting charges for original issuance costs associated with redeemedpreferred shares; allocations of FFO to holders of noncontrolling interests resulting from capital events; and certain otherexpenses that we believe are not closely correlated with our operating performance. Diluted FFO, as adjusted forcomparability also includes adjustments to Diluted FFO for the effects of the items noted above pertaining tounconsolidated real estate JVs that were allocable to our ownership interest in the JVs.

33

A. Definitions & Glossary» Diluted FFO per share – Defined as (1) Diluted FFO divided by (2) the sum of the (a) weighted average common shares

outstanding during a period, (b) weighted average common units outstanding during a period and (c) weighted averagenumber of potential additional common shares that would have been outstanding during a period if other securities thatare convertible or exchangeable into common shares were converted or exchanged. The computation of Diluted FFO pershare assumes the conversion of common units but does not assume the conversion of other securities that areconvertible into common shares if the conversion of those securities would increase Diluted FFO per share in a givenperiod.

» Diluted FFO per share, as adjusted for comparability – Defined as (1) Diluted FFO available to common share andcommon unit holders, as adjusted for comparability divided by (2) the sum of the (a) weighted average common sharesoutstanding during a period, (b) weighted average common units outstanding during a period and (c) weighted averagenumber of potential additional common shares that would have been outstanding during a period if other securities thatare convertible or exchangeable into common shares were converted or exchanged. The computation of this measureassumes the conversion of common units but does not assume the conversion of other securities that are convertible intocommon shares if the conversion of those securities would increase the per share measure in a given period.

» DISA – Defense Information Systems Agency» EBITDA – see Adjusted EBITDA» EUL – Enhanced Use Lease whereby the DOD grants a lease interest to a private developer in exchange for rent that the

DOD can use to improve the related defense installation.» Funds from operations (“FFO” or “FFO per Nareit”) – Defined as net income computed using GAAP, excluding gains

on sales and impairment losses of real estate (net of associated income tax) and real estate-related depreciation andamortization. FFO also includes adjustments to net income for the effects of the items noted above pertaining tounconsolidated real estate JVs that were allocable to our ownership interest in the JVs. We believe that we use theNational Association of Real Estate Investment Trust’s (“Nareit”) definition of FFO, although others may interpret thedefinition differently and, accordingly, our presentation of FFO may differ from those of other REITs.

» Gross Debt – Defined as total consolidated outstanding debt, which is debt reported per our balance sheet adjusted toexclude net discounts and premiums and deferred financing costs, as further adjusted to include outstanding debt ofunconsolidated real estate JVs that were allocable to our ownership interest in the JVs.

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A. Definitions & Glossary» GSA – United States General Services Administration. In July 1949, President Harry Truman established the GSA to

streamline the administrative work of the federal government. The GSA’s acquisition solutions supplies federalpurchasers with cost-effective high-quality products and services from commercial vendors. GSA provides workplaces forfederal employees, and oversees the preservation of historic federal properties. Its policies covering travel, property andmanagement practices promote efficient government operations.

» In-place adjusted EBITDA – Defined as Adjusted EBITDA, as further adjusted for: (1) the removal of NOI pertaining toproperties in the quarterly periods in which such properties were disposed or removed from service; (2) the addition of proforma adjustments to NOI for (a) properties acquired, placed in service or expanded upon subsequent to thecommencement of a quarter made in order to reflect a full quarter of ownership/operations and (b) significant mid-quarteroccupancy changes associated with properties recently placed in service with no occupancy; and (3) certain adjustmentsto deferred rental revenue associated with changes in our assessment of collectability that we believe are not closelycorrelated with our operating performance. The measure also includes adjustments to Adjusted EBITDA for the effects ofthe items noted above pertaining to unconsolidated real estate JVs that were allocable to our ownership interest in theJVs.

» Interest Duration – The length of time for which an interest rate on debt is fixed.» Market capitalization – sum of (1) consolidated outstanding debt, excluding discounts, premiums and deferred financing

costs, (2) liquidation value of preferred shares and preferred units in our operating partnership and (3) the product of theclosing price of our common shares on the NYSE and the sum of (a) common shares outstanding and (b) common unitsoutstanding.

» NGA – National Geospatial Intelligence Agency» Net debt – gross debt (total outstanding debt reported per our balance sheet as adjusted to exclude net discounts and

premiums and deferred financing costs), as adjusted to subtract cash and cash equivalents as of the end of the periodand debt in default that was extinguished via conveyance of properties. The measure also includes adjustments to Grossdebt for the effects of the items noted above pertaining to unconsolidated real estate JVs that were allocable to ourownership interest in the JVs.

» Net debt to adjusted book and Net debt plus preferred equity to Adjusted book – these measures divide either Netdebt or Net debt plus preferred equity by Adjusted book.

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A. Definitions & Glossary» Net debt to in-place adjusted EBITDA ratio and Net debt plus preferred equity to in-place adjusted EBITDA ratio –

Net debt (defined above) or Net debt plus preferred equity divided by in-place adjusted EBITDA (defined above) for the three month period that is annualized by multiplying by four.

» Net operating income from real estate operations (“NOI”) – Includes: consolidated real estate revenues; consolidated property operating expenses; and the net of revenues and property operating expenses of real estate operations owned through unconsolidated real estate JVs that are allocable to COPT’s ownership interest in the JVs.

» Payout ratios based on: Diluted FFO; Diluted FFO, as adjusted for comparability; and Diluted AFFO – These payout ratios are defined as (1) the sum of dividends on unrestricted common shares and distributions to holders of interests in the Operating Partnership (excluding unvested share-based compensation awards) and dividends on convertible preferred shares when such distributions and dividends are included in Diluted FFO divided by (2) the respective non-GAAP measures on which the payout ratios are based.

» Portfolio:

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A. Definitions & Glossary» Redevelopment – properties previously in operations on which activities to substantially renovate such properties are

underway or approved.» Regional Office Properties – office properties located in select urban/urban-like submarkets in the Greater

Washington, DC/Baltimore region with durable Class-A office fundamentals and characteristics.» Replacement capital expenditures – Tenant improvements and incentives, building improvements and leasing costs

incurred during the period for operating properties that are not (1) items contemplated prior to the acquisition of aproperty, (2) improvements associated with the expansion of a building or its improvements, (3) renovations to a buildingwhich change the underlying classification of the building (for example, from industrial to office or Class C office to ClassB office), (4) capital improvements that represent the addition of something new to the property rather than thereplacement of something (for example, the addition of a new heating and air conditioning unit that is not replacing onethat was previously there), or (5) replacements of significant components of a building after the building has reached theend of its original useful life. Replacement capital expenditures excludes expenditures of operating properties included indisposition plans during the period that were already sold or are held for future disposition. For cash tenant incentivesnot due to the tenant for a period exceeding three months past the date on which such incentives were incurred, werecognize such incentives as replacement capital expenditures in the periods such incentives are due to the tenant.Replacement capital expenditures, which is included in the computation of Diluted AFFO, is intended to represent non-transformative capital expenditures of existing properties held for long-term investment.

» Same-Properties – Operating office and data center shell properties stably owned and 100% operational since at leastthe beginning of the prior year.

» Same-Properties NOI and Same-Properties cash NOI – NOI, or Cash NOI, from real estate operations of Same-Properties.

» SCIF – a Sensitive (or Secure) Compartmented Information Facility, or “SCIF,” in U.S. military, security and intelligenceparlance is an enclosed area within a building that is used to process classified information within formal accesscontrolled systems (as established by the Director of National Intelligence).

» Stabilization – generally defined as properties that are at least 90% occupied.» Under development – This term includes properties under, or contractually committed for, development.

37

B. Reconciliations

Reconciliations of: EPS to FFOPS

GuidanceEPS to FFOPS per Nareit and as adjusted for comparability (in dollars per share) Low High Low HighEPS 0.63$ 0.65$ 0.77$ 0.79$ Real estate-related depreciation and amortization 0.36 0.36 1.27 1.27 Gain on sales of real estate (0.51) (0.51) (0.51) (0.51) Impairment losses - - 0.01 0.01 FFO allocation to other noncontrolling interest resulting from capital event - - (0.10) (0.10) FFOPS, Nareit definition 0.48$ 0.50$ 1.44$ 1.46$ FFO allocation to other noncontrolling interest resulting from capital event - - 0.10 0.10 Loss on interest rate derivatives and early extinguishment of debt 0.04 0.04 0.54 0.54 FFOPS, as adjusted for comparability 0.52$ 0.54$ 2.08$ 2.10$

Year Ending 12/31/20Three Months Ending 12/31/20

38

B. ReconciliationsFFO Reconciliation

(Dollars and shares in thousands, except per share data)3/31/20 6/30/20 9/30/20

Net income (loss) 25,550$ 25,121$ (31,342)$ Real estate-related depreciation and amortization 32,596 33,612 35,332 Impairment losses on real estate - - 1,530 Gain on sales of real estate (5) - - Depreciation and amortization on unconsolidated real estate JVs 818 818 819

FFO - per Nareit 58,959 59,551 6,339 Noncontrolling interests - preferred units in the Operating Partnership (77) (77) (77) FFO allocable to other noncontrolling interests (12,015) (1,525) (1,074) Basic FFO allocable to share-based compensation awards (193) (254) (119)

Basic FFO available to common share and common unit holders 46,674 57,695 5,069 Dilutive preferred units in the Operating Partnership - 77 - Redeemable noncontrolling interests 32 37 -

Diluted FFO available to common share and common unit holders 46,706 57,809 5,069 Loss on early extinguishment of debt - - 3,237 Loss on interest rate derivatives - - 53,196 Demolition costs on redevelopment and nonrecurring improvements 43 9 11 Dilutive preferred units in the Operating Partnership 77 - 77 FFO allocation to other noncontrolling interests resulting from capital event 11,090 - - Diluted FFO comparability adjustments for redeemable noncontrolling interests - - 34 Diluted FFO comparability adjustments allocable to share-based compensation awards (50) (1) (139)

Diluted FFO available to common share and common unit holders, as adjusted for comparability 57,866$ 57,817$ 61,485$

Denominator for diluted EPS 111,963 112,121 111,811 Weighted average common units 1,226 1,237 1,240 Redeemable noncontrolling interests 110 157 - Anti-dilutive EPS effect of share-based compensation awards - - 274 Dilutive convertible preferred units - 176 -

Denominator for diluted FFO per share 113,299 113,691 113,325 Dilutive convertible preferred units 176 - 176 Redeemable noncontrolling interests - - 109

Denominator for diluted FFO per share, as adjusted for comparability 113,475 113,691 113,610

Diluted FFO per share 0.41$ 0.51$ 0.04$ Diluted FFO per share, as adjusted for comparability 0.51$ 0.51$ 0.54$

Three Months Ended

39

B. ReconciliationsEBITDA Reconciliation

(Dollars in thousands)3/31/11 12/31/11 12/31/12 12/31/13 12/31/14 12/31/15 12/31/16 12/31/17 12/31/18 12/31/19 9/30/20

Reconciliations of GAAP net (loss) income to adjusted earnings before interest, income taxes,depreciation and amortization ("Adjusted EBITDA"):

Net (loss) income (18,566)$ (91,102)$ 19,010$ 92,672$ 5,937$ 62,617$ 26,255$ 11,008$ 18,456$ 44,877$ (31,342)$ Interest expense 26,928 24,914 22,782 23,181 23,286 22,347 18,664 19,211 18,475 16,777 17,152 Income tax (benefit) expense (544) (38) 54 1,917 53 46 272 953 (190) (104) 16 Depreciation and amortization 33,645 33,631 29,170 31,817 31,871 36,834 33,441 34,538 36,623 33,217 35,789 Impairment losses on real estate 27,742 78,674 2,140 921 48 19,744 1,554 13,659 2,367 2 1,530 Gain on sales of real estate (2,701) (3,362) 8 (9,004) (41) (64,047) (6,885) (4,452) (2,367) (20,761) - Adjustments from unconsolidated real estate joint ventures - - - - - - 830 829 832 1,206 1,274 Loss (gain) on early extinguishment of debt - 3 6 (67,808) 9,106 402 1,073 - 258 - 3,237 Loss on interest rate derivatives - 29,805 - - - - - - - - 53,196 Net (gain) loss on other investments (538) (771) (2,992) 221 (74) 6 (117) - (449) (1) 250 Credit loss recoveries - - - - - - - - - - (1,465) Business development expenses 465 1,064 654 644 669 1,512 1,167 1,116 661 512 414 EBITDA from properties to be conveyed to extinguish debt in default - - - - (828) - - - - - - Demolition costs on redevelopment and nonrecurring improvements - - - - - 225 - - 163 104 11 Executive transition costs - - - - 1,056 - 431 - 371 - - Operating property acquisition costs 23 4 - - - 32 - - - - - Non-comparable professional and legal expenses - - - - - - - - - 195 -

Adjusted EBITDA 66,454$ 72,822$ 70,832$ 74,561$ 71,083$ 79,718$ 76,685$ 76,862$ 75,200$ 76,024$ 80,062$ Proforma net operating income adjustment for property changes within period 562 (546) - (5,107) - (1,738) 39 (578) 2,052 463 1,631 Change in collectability of deferred rental revenue - - - - - - - - - 928 224

In-place adjusted EBITDA 67,016$ 72,276$ 70,832$ 69,454$ 71,083$ 77,980$ 76,724$ 76,284$ 77,252$ 77,415$ 81,917$ Annualized in-place adjusted EBITDA 268,064$ 289,104$ 283,328$ 277,816$ 284,332$ 311,920$ 306,896$ 305,136$ 309,008$ 309,660$ 327,668$

3/31/11 12/31/11 12/31/12 12/31/13 12/31/14 12/31/15 12/31/16 12/31/17 12/31/18 12/31/19 9/30/20Gross debt 2,412,821 2,438,471 2,027,792 1,935,718 1,929,810 2,097,230$ 1,950,229$ 1,872,167$ 1,868,504$ 1,893,057$ 2,247,523$ Less: Cash and cash equivalents (12,606) (5,559) (10,594) (54,373) (6,077) (60,310) (209,863) (12,261) (8,066) (14,733) (11,458) Less: Debt in default to be extinguished via conveyance of properties - - - - (150,000) - - - - - - Less: COPT's share of cash of unconsolidated real estate JVs - - - - - - (283) (371) (293) (498) (538) Net debt 2,400,215$ 2,432,912$ 2,017,198$ 1,881,345$ 1,773,733$ 2,036,920$ 1,740,083$ 1,859,535$ 1,860,145$ 1,877,826$ 2,235,527$ Preferred equity 225,133 225,133 342,633 257,883 207,883 207,883 207,883 8,800 8,800 8,800 8,800 Net debt plus preferred equity 2,625,348$ 2,658,045$ 2,359,831$ 2,139,228$ 1,981,616$ 2,244,803$ 1,947,966$ 1,868,335$ 1,868,945$ 1,886,626$ 2,244,327$

Net debt to in-place adjusted EBITDA ratio 9.0x 8.4x 7.1x 6.8x 6.2x 6.5x 5.7x 6.1x 6.0x 6.1x 6.8xNet debt plus preferred equity to in-place adjusted EBITDA ratio 9.8x 9.2x 8.3x 7.7x 7.0x 7.2x 6.3x 6.1x 6.0x 6.1x 6.8x

As of

Three Months Ended

Corporate Office Properties Trust

6711 Columbia Gateway Drive, Suite 300, Columbia, Maryland 21046

443.285.5400 / www.copt.com / NYSE: OFC