2017 Fourth Quarter Results Earnings Release Presentation January 18, 2018

This communication contains certain “forward-looking statements” about PacWest Bancorp (the “Company”) and its subsidiaries within the meaning of the Private Securities Litigation Reform Act of 1995, including certain plans, strategies, goals, and projections and including statements about our expectations regarding our allowance for loan and lease losses, credit trends, deposit growth, profitability, capital management, interest rate risk, estimated impacts of the Tax Cuts and Jobs Act and operating expenses. All statements contained in this communication that are not clearly historical in nature are forward-looking, and the words “anticipate,” “assume,” “intend,” “believe,” “forecast,” “expect,” “estimate,” “plan,” “continue,” “will,” “should,” “look forward” and similar expressions are generally intended to identify forward-looking statements. All forward-looking statements (including statements regarding future financial and operating results and future transactions and their results) involve risks, uncertainties and contingencies, many of which are beyond our control, which may cause actual results, performance, or achievements to differ materially from anticipated results, performance or achievements. Actual results could differ materially from those contained or implied by such forward-looking statements for a variety of factors, including without limitation: higher than anticipated delinquencies, charge-offs and loan and lease losses; reduced demand for our services due to strategic or regulatory reasons; changes in economic or competitive market conditions could negatively impact investment or lending opportunities or product pricing and services; credit quality deterioration or pronounced and sustained reduction in market values or other economic factors which adversely affect our borrowers’ ability to repay loans and leases and/or require an increased provision for loan and lease losses; compression of the net interest margin due to changes in our interest rate environment, loan products, spreads on newly originated loans and leases and/or asset mix; the impact of asset/liability repricing risk and liquidity risk on net interest margin and the value of investments; higher than anticipated increases in operating expenses; increased costs to manage and sell foreclosed assets; the need to retain capital for strategic or regulatory reasons; the financial performance of the Company; increased litigation; increased asset workout or loan servicing expenses; higher compensation costs and professional fees to retain and/or incent employees; our ability to complete future acquisitions, and to successfully integrate such acquired entities or achieve expected benefits, synergies and/or operating efficiencies within expected timeframes or at all; the impact of the Dodd-Frank Wall Street Reform and Consumer Protection Act on our business and business strategies; and other risk factors described in documents filed by the Company with the U.S. Securities and Exchange Commission (“SEC”). All forward-looking statements included in this communication are based on information available at the time of the communication. Pro forma, projected and estimated numbers are used for illustrative purposes only and are not forecasts, and actual results may differ materially. We are under no obligation to (and expressly disclaim any such obligation to) update or alter our forward-looking statements, whether as a result of new information, future events or otherwise except as required by law. Forward-Looking Statements

Fourth Quarter Highlights 4 Investment Securities 11 Loans and Leases 13 Credit Quality 17 Deposits 21 Controlled Expenses 24 Non-GAAP Measurements 27 Presentation Index

Fourth Quarter Highlights

Fourth Quarter Highlights Robust Earnings Net earnings of $84.0 million EPS of $0.66 ROAA and ROATE of 1.34% and 13.75% (1) Q4 includes $16.1 million of acquisition and integration costs related to CUB acquisition Industry Leading Net Interest Margin Tax equivalent NIM of 4.97% Yield on average loans and leases of 5.89% Low Efficiency Ratio Efficiency ratio of 41.0% Average branch size of $245 million in deposits Noninterest expense to average assets of 2.29% Profitable Deposit Base Cost of average total deposits of 30 bps $2.4 billion net core deposit growth, primarily from CUB acquisition Core deposits now represent 85% of total deposits Loan and Lease Production and Credit Quality Loan and lease production of $1.6 billion Organic loan and lease growth of 17% annualized NPAs to total loans and leases and foreclosed assets, excluding PCI loans, of 0.93% compared to 1.08% at September 30, 2017 Classified loans and leases to total loans and leases of 1.64% compared to 2.20% at September 30, 2017 Strong Capital Levels Tangible common equity ratio of 10.50% (1) CET1 and total capital ratios of 10.92% and 13.77% Tangible book value per share of $18.24 (1) See “Non-GAAP Measurements” slide on page 27.

Financial Highlights See “Non-GAAP Measurements” slide on page 27. ? ($ in millions, except per share amounts) 4Q17 3Q17 Q / Q Total Assets 24,995 $ 22,243 $ 12% Loans and Leases Held for Investment, net of deferred fees 16,973 $ 15,691 $ 8% Total Deposits 18,866 $ 16,773 $ 12% Core Deposits 15,937 $ 13,531 $ 18% Net Earnings 84.0 $ 101.5 $ -17% Earnings Per Share 0.66 $ 0.84 $ -21% Return on Average Assets ("ROAA") 1.34% 1.82% -0.48 Return on Average Tangible Equity ("ROATE") (1) 13.75% 16.85% -3.10 Tangible Common Equity Ratio (1) 10.50% 12.02% -1.52 Tangible Book Value Per Share (1) 18.24 $ 19.84 $ -8% Net Interest Margin 4.97% 5.08% -0.11 Efficiency Ratio 41.0% 40.4% 0.6

Solid Earnings Track Record ($ in millions, except Diluted EPS) 1Q16 2Q16 3Q16 4Q16 1Q17 2Q17 3Q17 4Q17 Net Earnings 90.5 $ 82.2 $ 93.9 $ 85.6 $ 78.7 $ 93.6 $ 101.5 $ 84.0 $ Diluted EPS 0.74 $ 0.68 $ 0.77 $ 0.71 $ 0.65 $ 0.77 $ 0.84 $ 0.66 $ $- $0.10 $0.20 $0.30 $0.40 $0.50 $0.60 $0.70 $0.80 $0.90 $0 $10 $20 $30 $40 $50 $60 $70 $80 $90 $100 $110 1Q16 2Q16 3Q16 4Q16 1Q17 2Q17 3Q17 4Q17 Diluted EPS Millions Net Earnings Diluted EPS

Source: SNL Financial. Peer data through 3Q17. Solid Capital Position – 4Q17 (Preliminary) 11.38% 11.87% 12.12% 12.19% 11.54% 11.67% 11.75% 12.02% 10.50% 8.54% 8.77% 8.68% 8.79% 8.63% 8.60% 8.75% 8.67% 4Q15 1Q16 2Q16 3Q16 4Q16 1Q17 2Q17 3Q17 4Q17 TCE / TA PACW Median Banks $15-$25B 11.67% 11.51% 11.92% 12.13% 11.91% 11.87% 11.90% 12.02% 10.66% 9.16% 8.99% 9.06% 9.11% 9.21% 9.30% 9.27% 9.37% 4Q15 1Q16 2Q16 3Q16 4Q16 1Q17 2Q17 3Q17 4Q17 T1 Leverage PACW Median Banks $15-$25B 15.65% 15.96% 16.08% 16.18% 15.56% 15.56% 15.42% 15.56% 13.77% 13.20% 13.16% 13.09% 12.99% 13.22% 12.95% 13.17% 13.00% 4Q15 1Q16 2Q16 3Q16 4Q16 1Q17 2Q17 3Q17 4Q17 Total Capital PACW Median Banks $15-$25B 12.58% 12.63% 12.72% 12.83% 12.31% 12.31% 12.28% 12.52% 10.92% 10.68% 10.64% 10.67% 10.48% 11.26% 11.15% 11.00% 10.67% 4Q15 1Q16 2Q16 3Q16 4Q16 1Q17 2Q17 3Q17 4Q17 CET1 PACW Median Banks $15-$25B

4Q17 Loan Sales/Loans Held For Sale Deemphasized cash flow lending; in 4Q17 made decision to sell cash flow loans totaling $1.5 billion and exit the CapitalSource Division origination operations related to general, technology and healthcare cash flow loans. Approximately $1.0 billion sold and settled prior to year-end Approximately $481 million sold of which 99% settled as of January 17, 2018 No nonaccrual loans sold $4.7 million of sold loans were classified Retained general, technology and healthcare cash flow portfolio contains approximately $39 million of classified loans at December 31, 2017 Impact to 4Q17 results and financial statements $481.1 million classified as LHFS on balance sheet at December 31, 2017 Gain on sale of loans of $2.0 million and other related costs of $1.3 million recorded to noninterest income Gross charge-offs in 4Q include $2.2 million to record LHFS at lower of cost or market (“LOCOM”) Decreased provision for loan losses of $14.1 million due in part to release of general reserves on loans transferred to LHFS in excess of LOCOM charge-offs Compensation expense of $2.9 million related to exiting certain lending operations $0.6 million noninterest expense charge related to sold unfunded commitments Increase in DTA valuation allowance of $2.0 million related to loans sold which generated foreign-sourced income utilized for foreign tax credits Healthcare Cash Flow, $411mm General Cash Flow, $356mm Technology Cash Flow, $705mm Loans Sold by Loan Type Total = $1.5 billion Healthcare, $29mm General, $20mm Technology, $200mm Retained General, Technology & Healthcare Cash Flow Loans Total = $249 million

Impacts in 4th quarter 2017: Net DTAs reduced from $65.3 million at 9/30/17 to a net DTL of $2.3 million at 12/31/17 driven by: Approximately $100 million of bonus tax depreciation for leased assets placed in service in Q4 which resulted in increased deferred tax liabilities of approximately $40 million Accelerated deduction of a portion of the 2017 bonuses deemed fixed and determinable (to be paid in 2018) which resulted in decreased deferred tax assets of approximately $15 million Re-measured federal deferred tax assets and liabilities at newly enacted federal tax rate of 21% which resulted in a $1.2 million tax benefit Sold approximately $173 million of securities to realize the loss of $3.3 million at the higher 35% tax rate; reinvested into higher yielding securities; recapture of loss expected in approximately one year Expected impacts going forward: Federal statutory corporate income tax rate reduced from 35% to 21% Allows for immediate capital expensing of certain qualified property Tax-equivalent net interest margin will be reduced by approximately 5 bps beginning in 2018 Performance based executive compensation now subject to $1 million deduction cap and definition of “covered person” expanded for senior executive officer compensation greater than $1 million Approximately 35% to 40% of our FDIC insurance assessments will no longer be deductible; deduction fully phased out at $50 billion in assets Analysis ongoing currently estimates that our 2018 effective tax rate will range from 27% to 29% Continue to analyze the new tax law and monitor guidance as issued Impacts of the Tax Cuts and Jobs Act

Investment Securities

3.73% overall portfolio tax equivalent yield (2) (1) Fair value (2) Yield is for 4Q17 Investment Portfolio Average Life and Effective Duration Municipal Securities Composition Diversified Investment Portfolio 6.1 7.0 6.7 6.8 7.0 4.8 5.7 5.7 5.9 6.0 3 4 5 6 7 8 4Q16 1Q17 2Q17 3Q17 4Q17 Years Average Life Effective Duration S&P Ratings % Total Issue Type % Total AAA 12% G.O. Limited 6% AA 79% G.O. Unlimited 45% A 3% Revenue 49% Not rated 6% 100% 100% Municipal Securities Collateralized Loan Obligations, $7.0mm, 0% SBA Securities, $160.3mm, 4% Agency Residential MBS, $246.3mm, 7% Agency Residential CMOs, $275.7mm, 7% Agency Commercial MBS, $1,164.0mm, 31% Private CMOs, $126.0mm, 3% Municipal Securities, $1,680.1mm, 45% Other, $115.1mm, 3% $3.8 Billion Total Portfolio (1)

Loans and Leases

Diversified Loan and Lease Portfolio Lender Finance & Timeshare Equipment Finance Healthcare Asset - Based Other Asset - Based Security Cash Flow Technology Cash Flow General and Other Cash Flow Healthcare Cash Flow Commercial Real Estate Income Producing Residential Construction and Land Healthcare Real Estate Small Business Owner - Occupied Residential Venture Capital Other As of December 31, 2017 ($ in millions) $ Mix $ Mix Lender Finance & Timeshare 1,610 $ 9% 1,667 $ 11% Equipment Finance 657 4% 692 4% Healthcare Asset-Based 93 1% 181 1% Other Asset-Based 1,308 8% 764 5% Total Asset-Based 3,668 22% 3,304 21% Security Cash Flow 573 3% 440 3% Technology Cash Flow 200 2% 1,048 7% General and Other Cash Flow 183 1% 564 4% Healthcare Cash Flow 29 0% 799 5% Total Cash Flow 985 6% 2,851 19% Commercial Real Estate 3,990 24% 2,987 19% Income Producing Residential 2,245 13% 1,169 8% Construction and Land 1,591 9% 965 6% Healthcare Real Estate 844 5% 955 6% Small Business 552 3% 454 3% Owner-Occupied Residential 222 1% 145 1% Total Real Estate 9,444 55% 6,675 43% Venture Capital 2,123 13% 1,988 13% Other 753 4% 638 4% Total Loans HFI (1) 16,973 $ 100% 15,456 $ 100% (1) Net of deferred fees and costs 12/31/2017 12/31/2016

Diversified Loan and Lease Portfolio Healthcare, $841mm, 9% SBA, $552mm, 6% Hospitality, $695mm, 7% Retail, $629mm, 7% Multifamily, $2,085mm, 22% Office, $912mm, 10% Owner - occupied, $1,314mm, 14% Construction, $1,591mm, 16% Other, $822mm, 9% Real Estate ($9.4B) Technology, $200mm, 20% Healthcare, $29mm, 3% Security, $573mm, 58% General, $20mm, 2% Municipal, $67mm, 7% SBA, $96mm, 10% Cash Flow ($1.0B) Lender Finance & Timeshare, $1,610mm, 44% Equipment Finance, $657mm, 18% Healthcare, $93mm, 2% Other, $1,308mm, 36% Asset - Based ($3.7B) Later Stage, $263mm, 12% Expansion Stage, $891mm, 45% Equity Funds Group, $471mm, 22% Early Stage, $443mm, 21% Venture Capital ($2.1B)

Loan and Lease Production of $1.6 Billion in 4Q17 The weighted average rate on new production presents contractual rates and does not include amortized fees. Amortized fees added approximately 30 basis points to loan yields in 2017. $1,273 $1,049 $1,078 $1,003 $1,556 $765 $1,057 $700 $722 $724 $709 $1,213 $956 $903 $729 $582 $732 $587 $638 $813 $2,038 $2,106 $1,778 $1,725 $2,280 $1,291 $1,945 $1,543 $1,541 $1,542 4.0% 4.5% 5.0% 5.5% 6.0% $0 $500 $1,000 $1,500 $2,000 $2,500 Q4 Q1 Q2 Q3 Q4 2016 2017 Avg. Rate on Production Millions Production Disbursements Payoffs Paydowns Avg Production/Disbursement Avg Payoffs/Paydowns Rate on Production ($ in millions) Production/ Disbursement Payoffs/ Paydowns Net Change Rate on Production (1) 4Q17 2,280 $ 1,542 $ 738 $ 4.95% 3Q17 1,725 1,541 184 5.04% 2Q17 1,778 1,543 235 4.93% 1Q17 2,106 1,945 161 4.91% 4Q16 2,038 1,291 747 4.83%

Credit Quality

Classified loans and leases are those with a credit risk rating of substandard or doubtful Allowance for credit losses includes allowance for loan and lease losses and reserve for unfunded commitments Non-PCI Credit Quality ($ in thousands) 4Q17 3Q17 2Q17 1Q17 4Q16 Nonaccrual Loans and Leases HFI $ 155,784 157,697 172,576 173,030 170,599 As a % of Loans and Leases HFI % 0.92% 1.00% 1.11% 1.11% 1.11% Nonperforming Assets (NPAs) $ 157,113 169,327 185,854 185,872 183,575 As a % of Loans and Leases & Foreclosed Assets % 0.93% 1.08% 1.20% 1.20% 1.19% Classified Loans and Leases HFI (1) $ 278,405 344,777 339,977 424,399 409,645 As a % of Loans and Leases HFI % 1.64% 2.20% 2.19% 2.73% 2.66% Credit Loss Provision $ 6,500 15,500 12,500 24,500 21,000 As a % of Average Loans and Leases (annualized) % 0.15% 0.40% 0.33% 0.64% 0.56% Trailing Twelve Months Net Charge-offs $ 62,957 53,991 56,802 36,287 21,990 As a % of Average Loans and Leases % 0.40% 0.35% 0.37% 0.24% 0.15% Allowance for Credit Losses (ACL) (2) $ 161,647 173,579 159,142 167,589 161,278 As a % of Loans and Leases HFI % 0.95% 1.11% 1.02% 1.08% 1.05% ACL / Nonaccrual Loans and Leases HFI % 103.77% 110.08% 92.22% 96.86% 94.54%

Key Credit Trends – Non-PCI Loans HFI 1.05% 1.08% 1.02% 1.11% 0.95% 4Q16 1Q17 2Q17 3Q17 4Q17 ACL / Loans and Leases 2.66% 2.73% 2.19% 2.20% 1.64% 4Q16 1Q17 2Q17 3Q17 4Q17 Classified Loans and Leases/ Average Loans and Leases 1.11% 1.11% 1.11% 1.00% 0.92% 4Q16 1Q17 2Q17 3Q17 4Q17 Nonaccrual Loans and Leases / Loans and Leases 1.19% 1.20% 1.20% 1.08% 0.93% 4Q16 1Q17 2Q17 3Q17 4Q17 NPAs / Loans and Leases and Foreclosed Assets

At December 31, 2017, the Company’s ten largest Non-PCI loan relationships on nonaccrual status had an aggregate book balance of $120 million and represented 77% of total Non-PCI nonaccrual loans and leases. Non-PCI Nonaccrual Loan and Lease Detail Excludes loans held for sale at lower of cost or fair value at December 31, 2017. The majority of the loans representing the increase in Non-PCI accruing and 30-89 days past due loans have subsequently been brought current, renewed or are subject to guarantees. % of Loan % of Loan 12/31/2017 9/30/2017 ($ in thousands) Balance Category Balance Category Balance Balance Real estate mortgage: Commercial 65,563 $ 1.2% 63,096 $ 1.5% 27,234 $ 1,446 $ Residential 3,350 0.1% 3,186 0.2% 6,629 282 Total real estate mortgage 68,913 0.9% 66,282 1.1% 33,863 1,728 Real estate construction and land: Commercial - 0.0% - 0.0% - - Residential - 0.0% - 0.0% 2,081 - Total R.E. construction and land - 0.0% - 0.0% 2,081 - Commercial: Cash flow 23,315 1.8% 33,514 1.2% 924 72 Equipment finance 30,938 4.7% 30,942 5.2% 1,512 - Venture capital 29,424 1.4% 22,686 1.2% 5,959 2,720 Asset-based 3,174 0.1% 3,977 0.2% 344 - Total commercial 86,851 1.2% 91,119 1.2% 8,739 2,792 Consumer 20 0.0% 296 0.1% 562 286 Total (1)(2) 155,784 $ 0.9% 157,697 $ 1.0% 45,245 $ 4,806 $ 12/31/2017 Nonaccrual Loans and Leases 9/30/2017 Accruing and 30 -89 Days Past Due

Deposits

Does not include $2.1 billion and $1.3 billion of client investment funds held at December 31, 2017 and December 31, 2016, respectively. Deposit Detail Core: 85% Core: 79% Noninterest - bearing demand deposits Interest checking deposits Money market deposits Savings deposits Non - core non - maturity deposits Time deposits $250,000 and under Time deposits over $250,000 December 31, 2017 Noninterest - bearing demand deposits Interest checking deposits Money market deposits Savings deposits Non - core non - maturity deposits Time deposits $250,000 and under Time deposits over $250,000 December 31, 2016 ($ in millions) Deposit Category Amount % of Total Amount % of Total Noninterest-bearing demand deposits 8,508 $ 45% 6,659 $ 42% Interest checking deposits 2,227 12% 1,448 9% Money market deposits 4,512 24% 3,706 23% Savings deposits 690 4% 711 5% Total core deposits 15,937 85% 12,524 79% Non-core non-maturity deposits 863 4% 1,175 7% Total non-maturity deposits 16,800 89% 13,699 86% Time deposits $250,000 and under 1,710 9% 1,758 11% Time deposits over $250,000 355 2% 414 3% Total time deposits 2,065 11% 2,172 14% Total deposits (1) 18,865 $ 100% 15,871 $ 100% December 31, 2017 December 31, 2016

Deposit Portfolio Includes brokered deposits of $682 million with a weighted average maturity of 4 months and a weighted average cost of 1.20%. $15.9 $16.3 $16.9 $16.8 $18.9 0.00% 0.10% 0.20% 0.30% 0.40% 0.50% 0.60% 0.0 5.0 10.0 15.0 20.0 25.0 4Q16 1Q17 2Q17 3Q17 4Q17 Cost Balance ($ in Billions) Core Deposits Non-Core Deposits Cost of Interest-Bearing Deposits Cost of Total Deposits ($ in millions) Time Deposits Time Deposits Total $250,000 Over Time Time Deposit Maturities and Under $250,000 Deposits Due in three months or less 632 $ 182 $ 814 $ Due in over three months through six months 516 101 617 Due in over six months through twelve months 446 54 500 Due in over 12 months through 24 months 77 10 87 Due in over 24 months 39 8 47 Total 1,710 $ (1) 355 $ 2,065 $ December 31, 2017

Controlled Expenses

Source: SNL Financial. Peer data through 3Q17. Efficiency Ratio Trend 38.0% 39.6% 39.3% 38.5% 40.6% 40.1% 40.1% 41.4% 40.3% 40.4% 41.0% 63.4% 65.9% 63.2% 64.3% 62.8% 61.8% 63.0% 62.9% 61.3% 60.3% 35.0% 40.0% 45.0% 50.0% 55.0% 60.0% 65.0% 70.0% 2Q15 3Q15 4Q15 1Q16 2Q16 3Q16 4Q16 1Q17 2Q17 3Q17 4Q17 PACW Efficiency Ratio Median Efficiency Ratio Banks $15-$25B

Focus and Execution Drive Efficiency 55.0% 54.0% 56.4% 60.7% 41.6% 38.5% 39.8% 40.8% 2010 2011 2012 2013 2014 2015 2016 2017 Efficiency Ratio $57 $60 $70 $72 $147 $193 $203 $245 2010 2011 2012 2013 2014 2015 2016 2017 Average Branch Size ($ - M)

The Company uses certain non-GAAP financial measures to provide meaningful supplemental information regarding the Company’s operational performance and to enhance investors’ overall understanding of such financial performance. These non-GAAP financial measures should not be considered a substitute for financial measures presented in accordance with GAAP and may be different from non-GAAP financial measures used by other companies. The table below presents reconciliations of certain GAAP to non-GAAP financial measures: Non-GAAP Measurements ($ in thousands, except per share amounts) December 31, 2017 September 30, 2017 June 30, 2017 March 31, 2017 December 31, 2016 Tangible Common Equity Ratio & Tangible Book Value Per Share Stockholders' equity 4,977,598 $ 4,610,668 $ 4,559,905 $ 4,508,106 $ 4,479,055 $ Less: Intangible assets 2,628,296 2,201,137 2,204,186 2,207,251 2,210,315 Tangible common equity 2,349,302 $ 2,409,531 $ 2,355,719 $ 2,300,855 $ 2,268,740 $ Total assets 24,994,876 $ 22,242,932 $ 22,246,877 $ 21,927,254 $ 21,869,767 $ Less: Intangible assets 2,628,296 2,201,137 2,204,186 2,207,251 2,210,315 Tangible assets 22,366,580 $ 20,041,795 $ 20,042,691 $ 19,720,003 $ 19,659,452 $ Tangible common equity ratio (1) 10.50% 12.02% 11.75% 11.67% 11.54% Tangible book value per share (2) 18.24 $ 19.84 $ 19.40 $ 18.95 $ 18.71 $ Shares outstanding 128,782,878 121,449,794 121,448,321 121,408,133 121,283,669 Return on Average Tangible Equity Net earnings 84,037 $ 101,466 $ 93,647 $ 78,668 $ 85,647 $ Average stockholders' equity 4,920,498 $ 4,592,489 $ 4,545,276 $ 4,503,675 $ 4,501,948 $ Less: Average intangible assets 2,495,876 2,202,922 2,205,814 2,209,112 2,212,042 Average tangible common equity 2,424,622 $ 2,389,567 $ 2,339,462 $ 2,294,563 $ 2,289,906 $ Return on average tangible equity (3) 13.75% 16.85% 16.06% 13.90% 14.88% (1) Tangible common equity divided by tangible assets (2) Tangible common equity divided by shares outstanding (3) Annualized net earnings divided by average tangible common equity. PacWest Bancorp Consolidated