a3q23earningspresentatio

October 23, 2023 Third Quarter 2023 Earnings Presentation

2 Nasdaq: BMRC This discussion of financial results includes forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, (the "1933 Act") and Section 21E of the Securities Exchange Act of 1934, as amended, (the "1934 Act"). Those sections of the 1933 Act and 1934 Act provide a "safe harbor" for forward-looking statements to encourage companies to provide prospective information about their financial performance so long as they provide meaningful, cautionary statements identifying important factors that could cause actual results to differ significantly from projected results. Our forward-looking statements include descriptions of plans or objectives of management for future operations, products or services, and forecasts of revenues, earnings or other measures of economic performance. Forward-looking statements can be identified by the fact that they do not relate strictly to historical or current facts. They often include the words "believe," "expect," "intend," "estimate" or words of similar meaning, or future or conditional verbs preceded by "will," "would," "should," "could" or "may." Forward-looking statements are based on management's current expectations regarding economic, legislative, and regulatory issues that may affect our earnings in future periods. Factors that could cause future results to vary materially from current management expectations include, but are not limited to, general economic conditions and the economic uncertainty in the United States and abroad, including economic or other disruptions to financial markets caused by acts of terrorism, war or other conflicts such as Russia's military action in Ukraine and more recently between Israel and Hamas, impacts from inflation, supply change disruptions, changes in interest rates (including the actions taken by the Federal Reserve to control inflation), California's unemployment rate, deposit flows, real estate values, and expected future cash flows on loans and securities; costs or effects of acquisitions; competition; changes in accounting principles, policies or guidelines; changes in legislation or regulation; natural disasters (such as wildfires and earthquakes in our area); adverse weather conditions; interruptions of utility service in our markets for sustained periods; and other economic, competitive, governmental, regulatory and technological factors (including external fraud and cybersecurity threats) affecting our operations, pricing, products and services; and successful integration of acquisitions. Important factors that could cause results or performance to materially differ from those expressed in our prior forward-looking statements are detailed in ITEM 1A, Risk Factors section of our December 31, 2022 Form 10-K as filed with the SEC, copies of which are available from us at no charge. Forward-looking statements speak only as of the date they are made. Bancorp undertakes no obligation to release publicly the result of any revisions to these forward-looking statements that may be made to reflect events or circumstances after the date of this press release or to reflect the occurrence of unanticipated events. GAAP to Non-GAAP Financial Measures This presentation includes some non-GAAP financial measures as shown in the Appendix of this presentation. Please refer to the reconciliation of GAAP to Non-GAAP financial measures included on pages 6 and 7 of our Form 8-K under Item 9 - Financial Statements and Exhibit 99.1 filed with the SEC on October 23, 2023. Forward-Looking Statements

Third Quarter 2023 Highlights 3 Nasdaq: BMRC Earnings and Profitability • Net Income of $5.3 million • Diluted EPS of $0.33 • Return on Average Assets of 0.52% • Return on Average Equity of 4.94% Key Operating Trends Loans and Credit Quality Deposits and Liquidity Capital • Tax-equivalent NIM of 2.48% • Tax-equivalent yield on interest-earning assets of 3.55%, up 4 bps from 2Q23 • Interest-bearing liabilities costs of 2.17%, up 8 bps from 2Q23 • Stable non-interest expense • Total deposits increased 3.6% from 2Q23, due to proactive prospect and customer outreach • Non-interest bearing deposits represent 48% of total deposits • Insured deposits estimated to represent 71% of total deposits • Strong liquidity provides 211% coverage of estimated uninsured deposits • Cash and unencumbered investment securities of $716.3 million • Other immediately available contingent funding of $1.4 billion • Bancorp total risk-based capital of 16.6% • Bancorp TCE / TA of 8.6%, 6.1% when adjusted for HTM securities 1 1See Reconciliation of Non-GAAP Financial Measures in the Appendix • Total portfolio loan balances decreased 0.8% from 2Q23 • Classified and non-accrual loans of 1.90% and 0.27% of total loans, respectively • Reported NOO-CRE office portfolio average LTV and DCR were materially unchanged

Strong Deposit Franchise 4 Nasdaq: BMRC • Total deposits increased $118.5 million or 3.6%, compared to June 30, 2023 • Deposit mix continues to favor a high percentage of non-interest bearing deposits • Total cost of deposits was 0.94% (interest-bearing 1.81%) for the quarter and 1.00% (interest-bearing 1.91%) for the month of September • Time deposit balances grew $28.9 million in Q3 with the total time deposit portfolio average maturity of approximately nine months and an average rate of 2.84% NIB DDA 47.7% Money Markets 31.7% Savings 7.5% IB DDA 6.4% Time Deposits 6.7% Total Deposit Mix ($3.44B) at 3Q23 NIB DDA 47.8% Money Markets 30.9% Savings 8.3% IB DDA 6.9% Time Deposits 6.1% Total Deposit Mix ($3.33B) at 2Q23

5 • YTD new accounts total over 3,600. • Q3 new accounts 50% interest-bearing by count • Q3 new accounts 83% interest-bearing in dollars at a weighted rate of 3.42% • Reciprocal deposit network program (expanded FDIC insurance products) utilization grew by $62.3 million in Q3. New Relationships 38% Existing - New $ 26% Existing - Movement 36% 1,267 New Accounts Mix (by count) 3Q23 Granular Deposit Account Composition 5 Nasdaq: BMRC (in thousands; except for # of Accounts) Interest Bearing Non-Interest Bearing Total Total Consumer $ 979,960 $ 362,389 $ 1,342,348 # of Accounts 15,387 17,596 32,983 Avg Balance Per Account $ 64 $ 21 $ 41 Total Business $ 822,766 $ 1,272,110 $ 2,094,876 # of Accounts 4,512 11,550 16,062 Avg Balance Per Account $ 182 $ 110 $ 130 *Excludes internal operating accounts totaling $6.5 million.

Strong Liquidity: $2.1 Billion in Net Availability 6 Nasdaq: BMRC At September 30, 2023 ($ in millions) Total Available Amount Used Net Availability Internal Sources Unrestricted Cash $ 102.6 $ — $ 102.6 Unencumbered Securities 613.7 — 613.7 External Sources FHLB 1,023.2 — 1,023.2 FRB 331.9 (120.0) 211.9 Contingent Lines at Correspondents 135.0 — 135.0 Total Liquidity $ 2,206.4 $ (120.0) $ 2,086.4 • The Bank has long-established minimum liquidity and diversification requirements using tools similar to large banks such as the Liquidity Coverage Ratio and multi-scenario, long-horizon stress testing • Deposit outflow assumptions for liquidity monitoring and stress testing are conservative relative to actual experience and have been reevaluated and updated subsequent to events of the first quarter • Markets and internal activity monitored daily for signs of systemic and idiosyncratic risk • Immediately available contingent funding represented 211% of 9/30/23 estimated uninsured deposits Note: Access to brokered deposit purchases through networks such as Intrafi and Reich & Tang and brokered CD sales not included above.

HTM Securities Portfolio Agency MBS/CMO 74% GSEs 16% Municipal Bonds 7% Corporate Bonds 3% AFS Securities Portfolio Agency MBS/CMO 59%GSEs 18% Municipal Bonds 13% SBA 4% Corporate Bonds & Other 5% USTs 1% High-Quality Securities Portfolio Generates Cash Flow Data as of 9/30/23 7 Nasdaq: BMRC $658.8MM $935.1MM Average Yield — 1.94% Approx. Duration — 4.07 Unrealized Losses (after tax) — $67.8MM TCE Bancorp — 8.6% Average Yield — 2.47% Approx. Duration — 5.95 Unrealized Losses (after tax) — $107.0MM TCE Bancorp w/ HTM — 6.1% 1 ($ in millions at Fair Value) ($ in millions at Cost) 1 See Reconciliation of Non-GAAP Financial Measures in the Appendix.

Well-diversified Loan Portfolio As of 9/30/23 - No material changes to Q2 2023 8 Nasdaq: BMRC • The loan portfolio is well-diversified across borrowers, industries, loan and property types within our geographic footprint — 93% of loans are guaranteed by borrower guarantors • Non-owner occupied commercial real estate ("NOO-CRE") is well-diversified by property type with 89% of loans being guaranteed by borrower guarantors • Since 2001, net charge-offs for all NOO-CRE total $1.2 million • Construction loans represent a small portion of the overall portfolio OO-CRE 17% C&I 8% Consumer 13% Construction 5% NOO-CRE 57% Office 30% Mixed Use 8% Retail 19% Warehouse & Industrial 12% Multi-Family 13% Other, 18% 3Q23 Total Loans 3Q23 Total NOO-CRE Loans $2.1B $1.2B

9 Nasdaq: BMRC • $364 million in exposure spread across our lending footprint comprised of 142 loans • $2.6 million average loan balance – largest loan at $17.0 million • 56% weighted average loan-to-value and 1.68x weighted average debt-service coverage ratio* • City of San Francisco NOO-CRE office exposure is 3% of total loan portfolio and 6% of total NOO-CRE loans Marin, 26% Sonoma, 14% San Francisco, 19% Alameda, 7% Sacramento, 6% Napa, 10% Other Bay Area, 14% Other, 4% NOO-CRE Office Portfolio by County City of S.F. NOO-CRE Office Portfolio Total Balance: $71.1MM Average Loan Bal: $6.5MM Number of Loans: 11 loans Wtd. Average LTV*: 66% Wtd. Average DCR*: 1.07x Average Occupancy*: 88% 10 of the 11 properties are low rise buildings, the other is 10 stories. $364MM *Based on the most recent annual review process Non-owner Occupied Office Exposure As of 9/30/23 - No material changes to Q2 2023

10 Nasdaq: BMRC Retail as of 3Q23 Warehouse & Industrial as of 3Q23 Multi-Family as of 3Q23 Marin, 18% Sonoma, 17% San Francisco, 3% Alameda, 6% Sacramento, 14% Napa, 18% Other Bay Area, 14% Other, 10% Marin, 14% Sonoma, 15% San Francisco, 26% Alameda, 15% Sacramento, 4% Napa, 6% Other Bay Area, 4% Other, 16% Marin, 11% Sonoma, 27% San Francisco, 11% Alameda, 18% Sacramento, 17% Napa, 3% Other Bay Area, 4% Other, 9% $233MM $150MM $143MM Avg. Loan Bal: $2.0MM Largest Bal: $15.0MM # of Loans: 70 Wtd. Avg. LTV*: 52% Avg. Loan Bal: $1.5MM Largest Bal: $11.9MM # of Loans: 103 Wtd. Avg. LTV*: 55% Avg. Loan Bal: $1.7MM Largest Bal: $14.2MM # of Loans: 135 Wtd. Avg. LTV*: 57% *Loan-to-values largely based on appraisal values at origination and loan balances as of 09/30/23 NOO-CRE Portfolio Diversified Across Property Types & Geographies As of 9/30/23 - No material changes to Q2 2023

Owner-Occupied CRE Portfolio As of 9/30/23 11 Nasdaq: BMRC Alameda, 14% Marin, 23% Napa, 17% Sacramento, 12% Sonoma, 10% Other, 24% OO CRE by Type as of 3Q23 OO CRE by County as of 3Q23 Office, 18% Industrial, 23% Retail, 7% School, 15% Wine, 10% Church, 7% Gas station/auto, 8% Heath club, 4% Mixed use, 3%Other, 5% Total Balance: $346.3MM # of Loans: 299 Avg. Loan Bal: $1.2MM Largest Loan Bal: $15.8MM Wtd. Avg. LTV*: 44% *Loan-to-value largely based on appraisal values at origination and loan balances as of 09/30/23 $346MM $346MM

12 Nasdaq: BMRC Marin, 8% Sonoma, 1% San Francisco, 47% Alameda, 29% Other Bay Area, 15% Construction by Type as of 3Q23 Construction by County as of 3Q23 Multi-family, 65% Self Storage, 10% 1-4 Residential, 24% Land & Ag, 1% Total Balance: $109.3MM Unfunded Commitments: $17.9MM # of Loans: 18 Avg. Loan Bal: $6.1MM Largest Loan Bal: $17.8MM Wtd. Avg. LTV*: 61% *Loan-to-value largely based on appraisal values at origination and loan balances as of 09/30/23 $109MM $109MM Construction Portfolio Concentrated in Lower-Risk Property Segments As of 9/30/23 - No material changes to Q2 2023

Low Refinance Risk in NOO CRE Portfolio through 2024 13 Nasdaq: BMRC # of loans Commitment Outstanding Balance Wtd. Avg. Rate Wtd. Avg. DSC Q4 2023 4 $12.6MM $11.6MM 3.80% 1.28x 2024 15 $43.0MM $36.9MM 4.73% 1.66x TOTAL 19 $55.6MM $48.5MM # of loans Commitment Outstanding Balance W.A. Rate Wtd. Avg. DSC Q4 2023 3 $7.2MM $7.2MM 4.76% 1.69x 2024 14 $34.7MM $34.7MM 4.26% 2.01x TOTAL 17 $41.9MM $41.9MM Maturing Loan Commitments > $1.0MM Repricing Loan Commitments > $1.0MM • We conducted a DEEP DIVE on loans maturing or repricing before year-end 2024 • PORTFOLIO IS WELL-POSITIONED TO ABSORB HIGHER RATE ENVIRONMENT AT MATURITY OR REPRICE • DSC Assumptions: Current interest rates, fully drawn commercial real estate lines of credit, 25-year amortization

History of Excellent Asset Quality 14 Nasdaq: BMRC • Consistent, robust credit culture and underwriting principles have supported excellent asset quality • Non-accrual loans continue to remain at historically low levels • Net charge-offs have consistently been negligible for the last five years • Adequate reserves with allowance for credit losses to total loans of 1.16% Non-accrual Loans / Total Loans 0.01% 0.44% 0.37% 0.12% 0.27% 2019 2020 2021 2022 3Q23 Non-accrual Loans / Total Loans Quarterly Progression 0.12% 0.10% 0.10% 0.27% 4Q22 1Q23 2Q23 3Q23

15 Nasdaq: BMRC 6.5% 8.0% 10.0% 5.0% 15.6% 15.6% 16.6% 10.2% 8.6% 6.1% Well Capitalized Threshold Bank of Marin Bancorp Bancorp TCE adj. for HTM securities* Common Equity Tier-One Risk-Based Capital Total Tier-One Risk-Based Capital Total Risk-Based Capital Tier-One Leverage Tangible Common Equity *See Reconciliation of Non-GAAP Financial Measures in the Appendix. Robust Capital Ratios As of 9/30/23

Net Interest Margin Drivers 16 Nasdaq: BMRC • Linked-quarter NIM increased 3 basis points, due primarily to the securities sales proceeds maintained in higher interest-bearing cash balances. • The cost of deposits increased to 100 basis points in the month of September compared to 82 basis points in June 2023. • The current cycle beta of 31% on non-maturity, interest-bearing deposits compares to our interest rate risk modeling assumption of 36%, which is doubled for stress testing. 0.17% 0.16% 0.17% 0.20% 0.23% 0.83% 1.15% 1.36% 1.60% 1.71% 1.81% 1.91% 3.08% 3.78% 4.10% 4.33% 4.57% 4.65% 4.83% 5.05% 5.08% 5.12% 5.33% 5.33% IB Deposits Fed Funds 10-22 11-22 12-22 1-23 2-23 3-23 4-23 5-23 6-23 7-23 8-23 9-23 2.45% 0.01% (0.07)% 0.11% (0.25)% 0.23% 2.48% 2Q23 Loans Securities Cash Deposits Borrowings 3Q23 Net Interest Margin Linked-Quarter Change Average Monthly Cost of IB Deposits vs. Fed Funds

Loans & Securities — Repricing & Maturity $ in millions, unless otherwise indicated 17 Nasdaq: BMRC Total Loans1 (1) Amounts represent amortized cost. Based on maturity date for fixed rate loans and variable rate loans at their floors and ceilings and next repricing date for all other variable rate loans. Does not included prepayment assumptions. (2) Includes both available-for-sale and held-to-maturity investment securities with prepayment assumptions applied. Repricing Term Rate Structure 3 mo or less 3-12 mos 1-3 years 3-5 years 5-15 years Over 15 years Total Floating Rate Variable Rate Variable Rate at Floor or Ceiling Fixed Rate C&I $ 76.3 $ 15.0 $ 23.2 $ 10.9 $ 45.6 $ 3.1 $ 174.1 $ 61.1 $ 12.5 $ 5.0 $ 95.5 Real estate: Owner-occupied CRE 4.5 8.3 36.2 65.7 224.5 7.1 346.3 0.6 24.2 117.4 204.1 Non-owner occupied CRE 25.5 50.4 176.1 225.0 699.2 14.6 1,190.8 0.7 89.5 340.7 759.9 Construction 53.2 26.3 0.7 — 29.1 — 109.3 3.5 — 9.8 96.0 Home equity 82.6 — — — 0.6 — 83.2 82.6 — — 0.6 Other residential 2.2 3.2 0.8 0.1 1.7 108.7 116.7 — 4.9 109.2 2.6 Installment & other consumer 0.5 0.6 8.0 4.3 52.9 0.2 66.5 0.2 6.0 10.5 49.8 Total $ 244.8 $ 103.8 $ 245.0 $ 306.0 $ 1,053.6 $ 133.7 $ 2,086.9 $ 148.7 $ 137.1 $ 592.6 $ 1,208.5 % of Total 12 % 5 % 12 % 15 % 50 % 6 % 100 % 7 % 7 % 28 % 58 % Weighted Average Rate 7.63 % 5.43 % 4.50 % 4.66 % 4.18 % 3.82 % 4.73 % * At September 30, 2023 Investment Securities2 Maturity & Projected Cash Flow Distribution 3 mo or less 3-12 mos 1-3 years 3-5 years 5-10 years Over 10 years Total Principal (par) & interest $ 31.3 $ 128.8 $ 388.1 $ 418.5 $ 634.3 $ 352.2 $ 1,953.2 % of Total 2 % 7 % 20 % 21 % 32 % 18 % 100 % * At September 30, 2023

Appendix

Reconciliation of GAAP to Non-GAAP Financial Measures 19 Nasdaq: BMRC (in thousands, unaudited) September 30, 2023 Tangible Common Equity - Bancorp Total stockholders' equity $ 418,618 Goodwill and core deposit intangible (76,850) Total TCE a 341,768 Unrealized losses on HTM securities, net of tax (107,011) TCE, net of unrealized losses on HTM securities (non-GAAP) b $ 234,757 Total assets $ 4,035,549 Goodwill and core deposit intangible (76,850) Total tangible assets c 3,958,699 Unrealized losses on HTM securities, net of tax (107,011) Total tangible assets, net of unrealized losses on HTM securities (non-GAAP) d $ 3,851,688 Bancorp TCE ratio a / c 8.6 % Bancorp TCE ratio, net of unrealized losses on HTM securities (non-GAAP) b / d 6.1 % For further discussion about our non-GAAP financial measures, refer to page 5 and 6 of our Form 8-K under Item 9 - Financial Statements and Exhibit 99.1 filed with the SEC on October 23, 2023.