Exhibit 99.1

•Net income was a record $124.93 million for the year of 2023, up 3.67% from 2022 and was $28.43 million for the fourth quarter of 2023, down 13.69% from the previous quarter and down 8.49% from the fourth quarter of 2022. Diluted net income per common share was a record $5.03 for the year of 2023, up 3.93% from 2022 and was $1.15 for the fourth quarter of 2023, down 12.88% from the previous quarter and down 8.00% from the prior year’s fourth quarter due primarily to repositioning of the investment securities portfolio and a contribution to the 1st Source Foundation as described below.

•Cash dividend of $0.34 per common share was approved, up 6.25% from the cash dividend declared a year ago.

•Average loans and leases grew $637.16 million in 2023, up 11.45% from 2022 and grew $141.98 million during the fourth quarter, up 2.27% (9.08% annualized growth) from the previous quarter.

•Tax-equivalent net interest margin was 3.51% for 2023, up six basis points from 2022 and was 3.51% for the fourth quarter of 2023, up five basis points from the prior quarter and down 18 basis points from the fourth quarter of 2022.

•During the fourth quarter, repositioning of the investment securities portfolio resulted in losses of $2.88 million on the sale of available-for-sale securities. Approximately $40 million of securities with an average yield of 1.10% were sold and used to purchase approximately $40 million of securities with an average yield of 4.80%.

•Charitable contribution of $1 million was made to the 1st Source Foundation during the fourth quarter.

•During 2023, gains on the sale of renewable energy tax equity investments of $3.43 million were recognized - $1.11 million during the first quarter and $2.32 million during the third quarter.

South Bend, IN — 1st Source Corporation (NASDAQ: SRCE), parent company of 1st Source Bank, today reported record net income of $124.93 million for 2023, an increase of 3.67% compared to $120.51 million earned in 2022. Fourth quarter net income was $28.43 million, a decrease of 8.49% compared to $31.07 million earned in the fourth quarter of 2022 after losses due to repositioning the Company’s investment securities portfolio and a contribution to the 1st Source Foundation. Diluted net income per common share for the year was a record $5.03, up 3.93% from the $4.84 earned a year earlier. Diluted net income per common share for the fourth quarter was $1.15, down 8.00% from the $1.25 earned in the fourth quarter of the previous year.

At its January 2024 meeting, the Board of Directors approved a cash dividend of $0.34 per common share, up 6.25% from the $0.32 per common share declared a year ago. The cash dividend is payable to shareholders of record on February 5, 2024 and will be paid on February 15, 2024.

Christopher J. Murphy III, Chairman and Chief Executive Officer, commented, “We are pleased to announce record net income for the third year in a row and we reached our 36th consecutive year of dividend growth. We were able to grow average loans and leases by $637.16 million or 11.45% from 2022. Our tax-equivalent net interest margin expanded during 2023 to 3.51% from 3.45% in 2022. During the fourth quarter, we also experienced margin expansion of six basis points after experiencing slight compression during the third quarter. New loans at higher rates, variable rate loan repricing and management of deposit rates contributed to the improvement. Our credit quality remained very strong as we had net recoveries to average loans and leases of 0.04% in 2023 compared to net charge-offs to average loans and leases of only 0.03% in 2022. I am extremely proud my colleagues were able to achieve such positive results during the unique challenges of 2023.

“In addition, we were most pleased to learn that 1st Source Bank received the Gold Level Award in the Community Lender category from the U.S. Small Business Administration (SBA) for the 11th consecutive year. The award, which focused on community banks headquartered in Indiana with less than $10 billion in assets, recognizes 1st Source Bank for delivering the greatest number of SBA loans in the State of Indiana in 2023. Since the inception of the award, it has been an honor to see the great work done by our SBA team and it is a testament to 1st Source Bank’s commitment to serving local small businesses in all our markets.

“In alignment with that commitment and our strategic initiative to grow 1st Source’s commercial banking footprint, we opened a loan production office in Lake County, Indiana in early January 2024. It is currently open by appointment only and serves the community with small business loans and other commercial credit needs. We are thrilled to expand into Lake County to help businesses in the area grow. Also, in line with our growth initiative, we have been moving forward with our efforts in Indianapolis. We opened a loan production office in the second quarter of 2023, and we have been continuing to build our presence in this market.

“Finally, in an ongoing effort to help our clients and to continue investment in our traditional markets, we are happy to announce that our new Niles Banking Center located at 1401 S. 11th St. in Niles, Michigan is now open to serve our clients. Recognizing the need for a new space as well as a drive-thru in Niles, the location opened successfully on December 21, 2023, and we are welcoming clients to come and experience enhanced levels of convenience and service,” Mr. Murphy concluded.

Annual average loans and leases of $6.20 billion increased $637.16 million, up 11.45% loans from the full year 2022. Quarterly average loans and leases of $6.39 billion increased $547.27 million, up 9.37% loans in the fourth quarter of 2023 from the year ago quarter and have increased $141.98 million, up 2.27% from the third quarter. Strong growth primarily within our Auto and Light Truck and Construction Equipment portfolios and selective growth in our Commercial Real Estate portfolio drove total average loans and leases higher during the year.

Annual average deposits for 2023 were $6.96 billion, an increase of $245.87 million, up 3.66% from 2022. Quarterly average deposits of $7.07 billion grew $310.20 million, up 4.59% for the quarter ended December 31, 2023 compared to the year ago quarter and have increased $118.56 million, up 1.71% compared to the third quarter. Deposit growth over the last year came from increased time deposits, public funds, and brokered deposits. The deposit mix change from 2022 continued through 2023 with clients moving their funds from non-maturity accounts to higher yielding certificates of deposit and money market accounts due to the interest rate environment.

For the twelve months of 2023, tax-equivalent net interest income was $279.39 million, an increase of $15.29 million, up 5.79% compared to the full year 2022. Fourth quarter 2023 tax-equivalent net interest income of $71.50 million decreased $0.17 million, down 0.24% from the fourth quarter a year ago and increased $2.09 million, or 3.01% from the third quarter.

Net interest margin for the year ending December 31, 2023 was 3.50%, an increase of six basis points from the 3.44% for the year ending December 31, 2022. Net interest margin on a tax-equivalent basis for the year ending December 31, 2023 was 3.51%, an increase of six basis points from the 3.45% for the year ending December 31, 2022. Net interest recoveries positively contributed two basis points to the tax-equivalent net interest margin compared to a positive three basis point impact during 2022.

Fourth quarter 2023 net interest margin was 3.51%, a decrease of 17 basis points from the 3.68% for the same period in 2022 and an increase of six basis points from the prior quarter. Fourth quarter 2023 net interest margin on a fully tax-equivalent basis was 3.51%, a decrease of 18 basis points from the 3.69% for the same period in 2022 and an increase of five basis points from the 3.46% in the prior quarter. Net interest recoveries had a positive four basis point impact on the fourth quarter net interest margin compared to a one basis point impact during the fourth quarter of 2022.

Noninterest income for the twelve months ended December 31, 2023 was $90.62 million, down $0.64 million or 0.70% compared to the twelve months ended December 31, 2022. Fourth quarter 2023 noninterest income of $20.08 million decreased $3.20 million, or 13.76% from the fourth quarter a year ago and decreased $4.38 million or 17.91% from the third quarter.

Noninterest income during the twelve months ended December 31, 2023 was lower compared to a year ago mainly from lower equipment rental income due to a decrease in the size of the equipment rental portfolio as demand for operating leases continues to decline. Also contributing to lower income was realized losses of $2.88 million from repositioning the available-for-sale investment securities portfolio during the fourth quarter. Noninterest income in 2023 was also impacted by reduced mortgage banking origination volumes resulting in lower income from loans sold into the secondary market. These decreases were offset by partnership investment gains on sale of renewable energy tax equity investments of $3.43 million, a rise in interest rate swap fees, and higher deposit account fees.

The decrease in noninterest income from the third quarter was mainly due to the losses on the sale of available-for-sale securities of $2.88 million as explained above and lower partnership investment gains mainly from the sale of renewable energy tax equity investments of $2.32 million during the third quarter. These were offset by increased trust and wealth advisory income primarily from the positive market performance during the quarter.

Noninterest expense for the twelve months ended December 31, 2023 was $201.72 million, an increase of $17.03 million, or 9.22% compared to the same period a year ago. Fourth quarter 2023 noninterest expense of $52.97 million rose $4.60 million, or 9.50% from the fourth quarter a year ago and increased $2.81 million or 5.59% from the prior quarter.

The increase in noninterest expense for 2023 from 2022 was primarily due to higher base salaries as a result of normal merit increases, the impact of wage inflation and an increase in the number of employees filling prior open positions, lower turn-over and a rise in group insurance claims. There was also increased software maintenance costs related to technology projects, higher FDIC insurance premiums due to a two basis point increase in assessment rates during the first quarter of 2023, an increase in the provision for unfunded loan commitments and a $1 million charitable contribution. These increases were offset by lower leased equipment depreciation and a decrease in professional consulting fees.

The increase in noninterest expense from the third quarter was mainly due to the earlier mentioned $1 million charitable contribution, higher legal fees and increased computer equipment replacement expense. These increases were offset by a lower provision for unfunded loan commitments and reduced leased equipment depreciation.

The allowance for loan and lease losses as of December 31, 2023 was 2.26% of total loans and leases compared to 2.27% at September 30, 2023 and 2.32% at December 31, 2022.

Net recoveries that have been recorded for the full year of 2023 were $2.42 million compared to net charge-offs of $1.47 million in 2022. This resulted in net recoveries to average loans and leases of 0.04% for 2023 compared to a net charge off ratio of 0.03% for 2022. Net recoveries in the fourth quarter of 2023 were $1.57 million compared with net charge-offs of $1.81 million in the same quarter a year ago and $0.33 million of net charge-offs in the previous quarter.

The provision for credit losses was $5.87 million for the twelve months ended December 31, 2023 and included $1.91 million for the fourth quarter of 2023, a decrease of $7.38 million and $3.43 million, respectively, compared with the same periods in 2022. The decrease in the provision expense was mainly due to net recoveries. The ratio of nonperforming assets to loans and leases was 0.37% as of December 31, 2023, compared to 0.27% on September 30, 2023 and 0.45% on December 31, 2022.

As of December 31, 2023, the common equity-to-assets ratio was 11.34%, compared to 10.84% at September 30, 2023 and 10.36% a year ago. The tangible common equity-to-tangible assets ratio was 10.48% at December 31, 2023 compared to 9.96% at September 30, 2023 and 9.45% a year earlier. The Common Equity Tier 1 ratio, calculated under banking regulatory guidelines, was 13.22% at December 31, 2023 compared to 13.31% at September 30, 2023 and 13.19% a year ago.

During 2023, 310,522 shares were repurchased for treasury reducing common shareholders’ equity by $12.47 million. No shares were repurchased during the fourth quarter 2023.

1st Source common stock is traded on the NASDAQ Global Select Market under “SRCE” and appears in the National Market System tables in many daily newspapers under the code name “1st Src.” Since 1863, 1st Source has been committed to the success of its clients, individuals, businesses and the communities it serves. For more information, visit www.1stsource.com.

1st Source serves the northern half of Indiana and southwest Michigan and is the largest locally controlled financial institution headquartered in the area. While delivering a comprehensive range of consumer and commercial banking services through its community bank offices, 1st Source has distinguished itself with highly personalized services. 1st Source Bank also competes for business nationally by offering specialized financing services for new and used private and cargo aircraft, automobiles for leasing and rental agencies, medium and heavy duty trucks, and construction equipment. The Corporation includes 78 banking centers, 18 1st Source Bank Specialty Finance Group locations nationwide, nine Wealth Advisory Services locations, 10 1st Source Insurance offices, and three loan production offices.

Except for historical information contained herein, the matters discussed in this document express “forward-looking statements.” Generally, the words “believe,” “contemplate,” “seek,” “plan,” “possible,” “assume,” “expect,” “intend,” “targeted,” “continue,” “remain,” “estimate,” “anticipate,” “project,” “will,” “should,” “indicate,” “would,” “may” and similar expressions indicate forward-looking statements. Those statements, including statements, projections, estimates or assumptions concerning future events or performance, and other statements that are other than statements of historical fact, are subject to material risks and uncertainties. 1st Source cautions readers not to place undue reliance on any forward-looking statements, which speak only as of the date made.

1st Source may make other written or oral forward-looking statements from time to time. Readers are advised that various important factors could cause 1st Source’s actual results or circumstances for future periods to differ materially from those anticipated or projected in such forward-looking statements. Such factors, among others, include changes in laws, regulations or accounting principles generally accepted in the United States; 1st Source’s competitive position within its markets served; increasing consolidation within the banking industry; unforeseen changes in interest rates; unforeseen downturns in the local, regional or national economies or in the industries in which 1st Source has credit concentrations; and other risks discussed in 1st Source’s filings with the Securities and Exchange Commission, including its Annual Report on Form 10-K, which filings are available from the SEC. 1st Source undertakes no obligation to publicly update or revise any forward-looking statements.

The accounting and reporting policies of 1st Source conform to generally accepted accounting principles (“GAAP”) in the United States and prevailing practices in the banking industry. However, certain non-GAAP performance measures are used by management to evaluate and measure the Company’s performance. Although these non-GAAP financial measures are frequently used by investors to evaluate a financial institution, they have limitations as analytical tools, and should not be considered in isolation, or as a substitute for analyses of results as reported under GAAP. These include taxable-equivalent net interest income (including its individual components), net interest margin (including its individual components), the efficiency ratio, tangible common equity-to-tangible assets ratio and tangible book value per common share. Management believes that these measures provide users of the Company’s financial information a more meaningful view of the performance of the interest-earning assets and interest-bearing liabilities and of the Company’s operating efficiency. Other financial holding companies may define or calculate these measures differently.

Management reviews yields on certain asset categories and the net interest margin of the Company and its banking subsidiaries on a fully taxable-equivalent (“FTE”) basis. In this non-GAAP presentation, net interest income is adjusted to reflect tax-exempt interest income on an equivalent before-tax basis. This measure ensures comparability of net interest income arising from both taxable and tax-exempt sources. Net interest income on a FTE basis is also used in the calculation of the Company’s efficiency ratio. The efficiency ratio, which is calculated by dividing non-interest expense by total taxable-equivalent net revenue (less securities gains or losses and lease depreciation), measures how much it costs to produce one dollar of revenue. Securities gains or losses and lease depreciation are excluded from this calculation to better match revenue from daily operations to operational expenses. Management considers the tangible common equity-to-tangible assets ratio and tangible book value per common share as useful measurements of the Company’s equity.

See the table marked “Reconciliation of Non-GAAP Financial Measures” for a reconciliation of certain non-GAAP financial measures used by the Company with their most closely related GAAP measures.

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(2) Calculated as common shareholders’ equity divided by common shares outstanding at the end of the period.

(3) Calculated as the sum of available-for-sale securities and loan and leases that mature in over 5 years as a percent of total assets.

The NASDAQ Stock Market National Market Symbol: “SRCE” (CUSIP #336901 10 3)

Please contact us at shareholder@1stsource.com