Corporate Structure and Nature of Operations: Basis of Presentation	9 Months Ended
Sep. 30, 2025
Corporate Structure and Nature of Operations; Basis of Presentation
Corporate Structure and Nature of Operations; Basis of Presentation	Note 1 – Corporate Structure and Nature of Operations; Basis of Presentation NB Bancorp, Inc., a Maryland corporation (the “Company”) (referred to herein as the “Company,” “we,” “us,” or “our”), is a bank holding company. Through its wholly-owned subsidiary, Needham Bank (the “Bank”), the Company provides a variety of banking services, through its full-service bank branches, located primarily in eastern Massachusetts. The activities of the Company are subject to the regulatory supervision of the Board of Governors of the Federal Reserve System. The activities of the Bank are subject to the regulatory supervision of the Massachusetts Commissioner of Banks and the Federal Deposit Insurance Corporation (“FDIC”). The Company and the activities of the Bank and its subsidiaries are also subject to various Massachusetts business and banking-related regulations. On June 5, 2025, the Company announced the signing of a definitive merger agreement under which the Company will acquire Provident Bancorp, Inc., with the Company as the surviving entity, and the Bank will acquire BankProv, the wholly owned subsidiary of Provident Bancorp, Inc., with the Bank as the surviving entity (the “Merger”). The transaction is valued at approximately $211.8 million. The closing of the Merger, which is expected to occur during the fourth quarter of 2025, was approved by the affirmative vote of the holders of a majority of Provident Bancorp, Inc. common stock and the receipt of required regulatory approvals from applicable state and federal regulators. Basis of Presentation The Company’s Consolidated Financial Statements have been prepared in conformity with accounting principles generally accepted in the United States (“U.S. GAAP”) as set forth by the Financial Accounting Standards Board (“FASB”) and its Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) as well as the rules and interpretive releases of the U.S. Securities and Exchange Commission (“SEC”) under the authority of federal securities laws. The Consolidated Financial Statements of the Company include the balances and results of operations of the Company and the Bank, its wholly-owned subsidiary, as well as the Bank’s wholly-owned subsidiaries, NeedCo-op Investment Corporation, Inc., 1892 Investments LLC and Eaton Square Realty LLC. All intercompany accounts and transactions have been eliminated in consolidation. Certain amounts, previously reported, have been reclassified to state all periods on a comparable basis and had no effect on shareholders’ equity or net income. The accompanying Consolidated Balance Sheet as of September 30, 2025, the Consolidated Statements of Income, Consolidated Statements of Comprehensive Income, Consolidated Statements of Changes in Shareholders’ Equity and Consolidated Statements of Cash Flows for the three and nine months ended September 30, 2025 and 2024 are unaudited. The Consolidated Balance Sheet as of December 31, 2024 was derived from the Audited Consolidated Financial Statements as of that date. The interim Consolidated Financial Statements and the accompanying notes should be read in conjunction with the annual Consolidated Financial Statements and the accompanying notes contained within the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2024, as filed with the SEC. In the opinion of management, the Company’s Consolidated Financial Statements reflect all adjustments, which include only normal recurring adjustments, necessary for a fair statement of the results of operations for the periods presented. The results for the three and nine months ended September 30, 2025 are not necessarily indicative of results to be expected for the year ending December 31, 2025, any other interim period, or any future year or period. The Company qualifies as an emerging growth company (“EGC”) under the Jumpstart Our Business Startups Act of 2012 and has elected to defer the adoption of new or revised accounting standards until the nonpublic company effective dates. As such, the Company will adopt standards on the nonpublic company effective dates until such time that we no longer qualify as an EGC. Subsequent events are events or transactions that occur after the consolidated balance sheet date but before consolidated financial statements are issued. Recognized subsequent events are events or transactions that provide additional evidence about conditions that existed at the date of the consolidated balance sheet, including the estimates inherent in the process of preparing consolidated financial statements. Non-recognized subsequent events are events that provide evidence about conditions that did not exist at the date of the consolidated balance sheet but arose after that date. Operating Segments The Company adopted FASB ASU 2023-07 “Segment Reporting (Topic 280) - Improvement to Reportable Segment Disclosures” on January 1, 2024, which requires that information be reported about a company’s operating segments using a “management approach.” Reportable segments are identified in these standards as those revenue producing components for which separate financial information is produced internally and which are subject to evaluation by the chief operating decision maker (“CODM”). The Company has determined that its CODM is its Chief Executive Officer. The Company has one reportable segment: its banking business, which consists of a full range of banking, lending, savings, and small business offerings. The CODM regularly assesses performance of the aggregated single operating and reporting segment and decides how to allocate resources based on net income calculated on the same basis as is net income reported in the Company’s consolidated statements of income and other comprehensive income. The CODM is also regularly provided with expense information at a level consistent with that disclosed in the Company’s consolidated statements of income and other comprehensive income.

Corporate Structure and Nature of Operations: Basis of Presentation

9 Months Ended

Sep. 30, 2025

Corporate Structure and Nature of Operations; Basis of Presentation

Corporate Structure and Nature of Operations; Basis of Presentation

Note 1 – Corporate Structure and Nature of Operations; Basis of Presentation

NB Bancorp, Inc., a Maryland corporation (the “Company”) (referred to herein as the “Company,” “we,” “us,” or “our”), is a bank holding company. Through its wholly-owned subsidiary, Needham Bank (the “Bank”), the Company provides a variety of banking services, through its full-service bank branches, located primarily in eastern Massachusetts.

The activities of the Company are subject to the regulatory supervision of the Board of Governors of the Federal Reserve System. The activities of the Bank are subject to the regulatory supervision of the Massachusetts Commissioner of Banks and the Federal Deposit Insurance Corporation (“FDIC”). The Company and the activities of the Bank and its subsidiaries are also subject to various Massachusetts business and banking-related regulations.

On June 5, 2025, the Company announced the signing of a definitive merger agreement under which the Company will acquire Provident Bancorp, Inc., with the Company as the surviving entity, and the Bank will acquire BankProv, the wholly owned subsidiary of Provident Bancorp, Inc., with the Bank as the surviving entity (the “Merger”). The transaction is valued at approximately $211.8 million. The closing of the Merger, which is expected to occur during the fourth quarter of 2025, was approved by the affirmative vote of the holders of a majority of Provident Bancorp, Inc. common stock and the receipt of required regulatory approvals from applicable state and federal regulators.

Basis of Presentation

The Company’s Consolidated Financial Statements have been prepared in conformity with accounting principles generally accepted in the United States (“U.S. GAAP”) as set forth by the Financial Accounting Standards Board (“FASB”) and its Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) as well as the rules and interpretive releases of the U.S. Securities and Exchange Commission (“SEC”) under the authority of federal securities laws.

The Consolidated Financial Statements of the Company include the balances and results of operations of the Company and the Bank, its wholly-owned subsidiary, as well as the Bank’s wholly-owned subsidiaries, NeedCo-op Investment Corporation, Inc., 1892 Investments LLC and Eaton Square Realty LLC. All intercompany accounts and transactions have been eliminated in consolidation.

Certain amounts, previously reported, have been reclassified to state all periods on a comparable basis and had no effect on shareholders’ equity or net income.

The accompanying Consolidated Balance Sheet as of September 30, 2025, the Consolidated Statements of Income, Consolidated Statements of Comprehensive Income, Consolidated Statements of Changes in Shareholders’ Equity and Consolidated Statements of Cash Flows for the three and nine months ended September 30, 2025 and 2024 are unaudited. The Consolidated Balance Sheet as of December 31, 2024 was derived from the Audited Consolidated Financial Statements as of that date. The interim Consolidated Financial Statements and the accompanying notes should be read in conjunction with the annual Consolidated Financial Statements and the accompanying notes contained within the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2024, as filed with the SEC. In the opinion of management, the Company’s Consolidated Financial Statements reflect all adjustments, which include only normal recurring adjustments, necessary for a fair statement of the results of operations for the periods presented. The results for the three and nine months ended September 30, 2025 are not necessarily indicative of results to be expected for the year ending December 31, 2025, any other interim period, or any future year or period.

The Company qualifies as an emerging growth company (“EGC”) under the Jumpstart Our Business Startups Act of 2012 and has elected to defer the adoption of new or revised accounting standards until the nonpublic company effective dates. As such, the Company will adopt standards on the nonpublic company effective dates until such time that we no longer qualify as an EGC.

Subsequent events are events or transactions that occur after the consolidated balance sheet date but before consolidated financial statements are issued.

Recognized subsequent events are events or transactions that provide additional evidence about conditions that existed at the date of the consolidated balance sheet, including the estimates inherent in the process of preparing consolidated financial statements. Non-recognized subsequent events are events that provide evidence about conditions that did not exist at the date of the consolidated balance sheet but arose after that date.

Operating Segments

The Company adopted FASB ASU 2023-07 “Segment Reporting (Topic 280) - Improvement to Reportable Segment Disclosures” on January 1, 2024, which requires that information be reported about a company’s operating segments using a “management approach.” Reportable segments are identified in these standards as those revenue producing components for which separate financial information is produced internally and which are subject to evaluation by the chief operating decision maker (“CODM”). The Company has determined that its CODM is its Chief Executive Officer. The Company has one reportable segment: its banking business, which consists of a full range of banking, lending, savings, and small business offerings. The CODM regularly assesses performance of the aggregated single operating and reporting segment and decides how to allocate resources based on net income calculated on the same basis as is net income reported in the Company’s consolidated statements of income and other comprehensive income. The CODM is also regularly provided with expense information at a level consistent with that disclosed in the Company’s consolidated statements of income and other comprehensive income.