Organization and Description of Business	3 Months Ended
Mar. 31, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	1. Organization and Description of Business Business Operations Cardinal Infrastructure Group Inc. (“PubCo,” the “Company,” or “Cardinal Group”) is a Delaware corporation formed on June 12, 2025, for the purpose of facilitating an initial public offering (the “IPO”) and related organizational transactions in order to acquire an investment in Cardinal Civil Contracting Holdings LLC (“Cardinal” or "OpCo"). Cardinal Group is a holding company with no direct operations whose principal asset is its equity interest in Cardinal, acquired in connection with the IPO. Cardinal is a Delaware limited liability company formed on September 16, 2025, whose primary asset is its 100% ownership interest in Cardinal Civil Contracting, LLC (“Cardinal NC”), a North Carolina limited liability company organized on January 16, 2013 that conducts all operations of the Company through its wholly owned subsidiaries. The Company is a leading provider of site development and infrastructure services in the southeastern United States. The Company serves residential, commercial and municipal end markets and operates primarily in North Carolina and surrounding regions. Up-C Structure The Company’s organizational structure following the IPO is commonly referred to as an umbrella partnership–C corporation (“Up-C”) structure, which is often used by partnerships and limited liability companies undertaking an initial public offering. The Up-C structure allows the Continuing Equity Holders (as defined below) to retain their equity ownership in Cardinal, an entity treated as a partnership for U.S. federal income tax purposes, and to continue to realize tax benefits associated with owning interests in a flow-through entity. Investors in the Company hold their equity ownership through shares of Class A Common Stock of PubCo, a Delaware corporation subject to corporate-level taxation. As the sole managing member of Cardinal, the Company operates and controls all of the business and affairs of Cardinal and, through Cardinal and its subsidiaries, conducts all of the Company’s business. Accordingly, the Company consolidates the financial results of Cardinal and reports the economic interests in Cardinal held by the Continuing Equity Holders as noncontrolling interests in the consolidated financial statements. Initial Public Offering On December 11, 2025, the Company completed its IPO of 11,500,000 shares of Class A Common Stock, par value $0.0001 per share, at a price to the public of $21.00 per share. On December 12, 2025, pursuant to the exercise in full of the underwriters’ option to purchase additional shares, the Company completed the sale of an additional 1,725,000 shares of Class A Common Stock at the IPO price. Gross proceeds from the IPO, including the overallotment, were approximately $277.7 million before deducting underwriting discounts and other offering costs. The Company used the net proceeds from the IPO to purchase 14,943,750 newly issued LLC units from Cardinal for net payment of approximately $252.3 million in the aggregate and became the sole managing member of Cardinal. Cardinal in turn used $157.5 million of the net proceeds to exchange and redeem 7,500,000 LLC units of Cardinal certain equity holders of Cardinal (the “Continuing Equity Holders”) and repay approximately $24.3 million of borrowings outstanding under our October 2025 Credit Facility. In connection with the IPO, the Company also issued 23,387,813 shares of Class B Common Stock to the Continuing Equity Holders, which was equal to the number of LLC units held by such Continuing Equity Holders at the time of issuance, for nominal consideration. Reorganization Transactions Prior to the IPO, all of the Company’s business was conducted through Cardinal NC. In connection with the IPO, the Company completed a series of organizational transactions (the “Reorganization Transactions”) to reorganize its corporate structure. The IPO and the Reorganization Transactions are collectively referred to herein as the “Transactions.” The Reorganization Transactions consisted of two discrete transactions, the “September 2025 Reorganization” and the “IPO Reorganization,” which are each described below. September 2025 Reorganization Effective September 30, 2025, the Company completed the first step of the Reorganization Transactions (the “September 2025 Reorganization”). The Company merged newly formed merger subsidiaries of Cardinal NC with and into each of Cardinal NC’s non-wholly owned subsidiaries so that the minority equity holders of such non-wholly owned subsidiaries became equity holders of Cardinal and such non-wholly owned subsidiaries became wholly owned subsidiaries of Cardinal NC. Subsequently, a newly formed merger subsidiary of Cardinal was merged with and into Cardinal NC so that the members of Cardinal NC became members of Cardinal and Cardinal NC became a wholly owned subsidiary of Cardinal. As a result of the September 2025 Reorganization, the existing ownership interests of Cardinal NC were recapitalized from multiple classes (Class A, B and C units) into a single common class of LLC units. The minority equity holders of the non-wholly owned subsidiaries received newly issued LLC units in Cardinal in exchange for their subsidiary-level interests, which were cancelled. In the accompanying consolidated statement of changes in equity, the September 2025 Reorganization is reflected as: (i) the reclassification of the carrying amounts of previously reported noncontrolling interests in subsidiaries to members’ equity, and (ii) the recapitalization of the existing unit classes into a single class of LLC units, with no change in the total carrying amount of equity. IPO Reorganization On December 10, 2025, immediately prior to and in connection with the closing of the IPO, the Company completed the second step of the Reorganization Transactions (the “IPO Reorganization”). The IPO Reorganization consisted of the following: • The Company amended and restated the Cardinal operating agreement to, among other things, (i) recapitalize all existing ownership interests, (ii) appoint Cardinal Infrastructure Group Inc. as the sole managing member of Cardinal upon its acquisition of LLC units in connection with the IPO, and (iii) provide certain redemption rights to the Continuing Equity Holders. • Cardinal Infrastructure Group Inc. amended and restated its certificate of incorporation to, among other things, (i) reclassify all outstanding shares of common stock into 1,718,750 shares of Class A Common Stock, as adjusted for an approximately 86-to-one forward stock split, (ii) provide for Class A Common Stock and Class B Common Stock, each entitling the holder to one vote per share on all matters presented to stockholders, (iii) provide that shares of Class B Common Stock may only be held by the Continuing Equity Holders and their permitted transferees, and (iv) authorize 10,000,000 shares of preferred stock, par value $0.0001 per share, issuable by the Board of Directors in one or more series without stockholder approval. • Cardinal Infrastructure Group Inc. acquired newly issued LLC units from Cardinal using the net proceeds of the IPO and became the sole managing member of Cardinal. • Cardinal Infrastructure Group Inc. issued 23,387,813 shares of Class B Common Stock to the Continuing Equity Holders, on a one-for-one basis with their LLC units, for nominal consideration. In the accompanying condensed consolidated statements of changes in stockholders'/members' equity, the IPO Reorganization is reflected as: (i) the conversion of members’ equity to the recapitalized equity structure of Cardinal Infrastructure Group Inc. (Class A Common Stock, Class B Common Stock, and additional paid-in capital), (ii) the receipt of net IPO proceeds in exchange for newly issued LLC units, (iii) the recognition of noncontrolling interests representing the Continuing Equity Holders’ 61.0% economic interest in Cardinal, and (iv) the establishment of Cardinal Infrastructure Group Inc. as a reporting entity with the accompanying reclassification of the predecessor equity accounts. Both the September 2025 Reorganization and the IPO Reorganization are accounted for as transactions among entities under common control. As Cardinal Infrastructure Group Inc. had no substantive operations prior to the IPO and the Continuing Equity Holders retained their majority economic interest (61.0%) in Cardinal, the Transactions are treated as a recapitalization rather than a business combination. The September 2025 Reorganization, in which the pre-existing minority equity holders of Cardinal NC’s non-wholly owned subsidiaries exchanged their subsidiary-level interests for LLC units of Cardinal, was accounted for as an acquisition of noncontrolling interests in accordance with Accounting Standards Codification ("ASC") 810-10-45-23, with the carrying amounts of noncontrolling interests reclassified to members’ equity with no gain or loss recognized. The IPO Reorganization, in which Cardinal Infrastructure Group Inc. became the sole managing member of Cardinal and completed the IPO, was accounted for as a recapitalization of the predecessor operating entity. The accompanying consolidated financial statements represent a continuation of the historical financial statements of Cardinal, with the exception of the recapitalized equity structure. Comparative information for periods prior to the Transactions reflects the historical financial statements of Cardinal. Basis of Accounting The accompanying condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The unaudited interim condensed consolidated financial statements include the results of the Company and its wholly owned or controlled subsidiaries. All significant intercompany transactions and balances have been eliminated during consolidation. In the opinion of management, the condensed consolidated financial statements reflect all adjustments, which are necessary for the fair presentation of the financial condition, and results of operations for the interim periods presented. The accompanying condensed consolidated financial statements were prepared in accordance with the requirements for interim financial information. Accordingly, these interim financial statements have not been audited and exclude certain disclosures required for annual financial statements. We have historically experienced, and in the future expect to continue to experience, variability in our results on a quarterly basis. Due to the seasonality of the Company's businesses, the operating results presented for interim periods are not necessarily indicative of the results that may be expected for any other interim period or for the entire year. These interim financial statements should be read in conjunction with the audited consolidated financial statements of the Company included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025.

Organization and Description of Business

3 Months Ended

Mar. 31, 2026

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization and Description of Business

1. Organization and Description of Business

Business Operations

Cardinal Infrastructure Group Inc. (“PubCo,” the “Company,” or “Cardinal Group”) is a Delaware corporation formed on June 12, 2025, for the purpose of facilitating an initial public offering (the “IPO”) and related organizational transactions in order to acquire an investment in Cardinal Civil Contracting Holdings LLC (“Cardinal” or "OpCo"). Cardinal Group is a holding company with no direct operations whose principal asset is its equity interest in Cardinal, acquired in connection with the IPO.

Cardinal is a Delaware limited liability company formed on September 16, 2025, whose primary asset is its 100% ownership interest in Cardinal Civil Contracting, LLC (“Cardinal NC”), a North Carolina limited liability company organized on January 16, 2013 that conducts all operations of the Company through its wholly owned subsidiaries.

The Company is a leading provider of site development and infrastructure services in the southeastern United States. The Company serves residential, commercial and municipal end markets and operates primarily in North Carolina and surrounding regions.

Up-C Structure

The Company’s organizational structure following the IPO is commonly referred to as an umbrella partnership–C corporation (“Up-C”) structure, which is often used by partnerships and limited liability companies undertaking an initial public offering. The Up-C structure allows the Continuing Equity Holders (as defined below) to retain their equity ownership in Cardinal, an entity treated as a partnership for U.S. federal income tax purposes, and to continue to realize tax benefits associated with owning interests in a flow-through entity. Investors in the Company hold their equity ownership through shares of Class A Common Stock of PubCo, a Delaware corporation subject to corporate-level taxation.

As the sole managing member of Cardinal, the Company operates and controls all of the business and affairs of Cardinal and, through Cardinal and its subsidiaries, conducts all of the Company’s business. Accordingly, the Company consolidates the financial results of Cardinal and reports the economic interests in Cardinal held by the Continuing Equity Holders as noncontrolling interests in the consolidated financial statements.

Initial Public Offering

On December 11, 2025, the Company completed its IPO of 11,500,000 shares of Class A Common Stock, par value $0.0001 per share, at a price to the public of $21.00 per share. On December 12, 2025, pursuant to the exercise in full of the underwriters’ option to purchase additional shares, the Company completed the sale of an additional 1,725,000 shares of Class A Common Stock at the IPO price. Gross proceeds from the IPO, including the overallotment, were approximately $277.7 million before deducting underwriting discounts and other offering costs.

The Company used the net proceeds from the IPO to purchase 14,943,750 newly issued LLC units from Cardinal for net payment of approximately $252.3 million in the aggregate and became the sole managing member of Cardinal. Cardinal in turn used $157.5 million of the net proceeds to exchange and redeem 7,500,000 LLC units of Cardinal certain equity holders of Cardinal (the “Continuing Equity Holders”) and repay approximately $24.3 million of borrowings outstanding under our October 2025 Credit Facility. In connection with the IPO, the Company also issued 23,387,813 shares of Class B Common Stock to the Continuing Equity Holders, which was equal to the number of LLC units held by such Continuing Equity Holders at the time of issuance, for nominal consideration.

Reorganization Transactions

Prior to the IPO, all of the Company’s business was conducted through Cardinal NC. In connection with the IPO, the Company completed a series of organizational transactions (the “Reorganization Transactions”) to reorganize its corporate structure. The IPO and the Reorganization Transactions are collectively referred to herein as the “Transactions.” The Reorganization Transactions consisted of two discrete transactions, the “September 2025 Reorganization” and the “IPO Reorganization,” which are each described below.

September 2025 Reorganization

Effective September 30, 2025, the Company completed the first step of the Reorganization Transactions (the “September 2025 Reorganization”). The Company merged newly formed merger subsidiaries of Cardinal NC with and into each of Cardinal NC’s non-wholly owned subsidiaries so that the minority equity holders of such non-wholly owned subsidiaries became equity holders of Cardinal and such non-wholly owned subsidiaries became wholly owned subsidiaries of Cardinal NC. Subsequently, a newly formed merger subsidiary of Cardinal was merged with and into Cardinal NC so that the members of Cardinal NC became members of Cardinal and Cardinal NC became a wholly owned subsidiary of Cardinal.

As a result of the September 2025 Reorganization, the existing ownership interests of Cardinal NC were recapitalized from multiple classes (Class A, B and C units) into a single common class of LLC units. The minority equity holders of the non-wholly owned subsidiaries received newly issued LLC units in Cardinal in exchange for their subsidiary-level interests, which were cancelled. In the accompanying consolidated statement of changes in equity, the September 2025 Reorganization is reflected as: (i) the reclassification of the carrying amounts of previously reported noncontrolling interests in subsidiaries to members’ equity, and (ii) the recapitalization of the existing unit classes into a single class of LLC units, with no change in the total carrying amount of equity.

IPO Reorganization

On December 10, 2025, immediately prior to and in connection with the closing of the IPO, the Company completed the second step of the Reorganization Transactions (the “IPO Reorganization”). The IPO Reorganization consisted of the following:

•

The Company amended and restated the Cardinal operating agreement to, among other things, (i) recapitalize all existing ownership interests, (ii) appoint Cardinal Infrastructure Group Inc. as the sole managing member of Cardinal upon its acquisition of LLC units in connection with the IPO, and (iii) provide certain redemption rights to the Continuing Equity Holders.

•

Cardinal Infrastructure Group Inc. amended and restated its certificate of incorporation to, among other things, (i) reclassify all outstanding shares of common stock into 1,718,750 shares of Class A Common Stock, as adjusted for an approximately 86-to-one forward stock split, (ii) provide for Class A Common Stock and Class B Common Stock, each entitling the holder to one vote per share on all matters presented to stockholders, (iii) provide that shares of Class B Common Stock may only be held by the Continuing Equity Holders and their permitted transferees, and (iv) authorize 10,000,000 shares of preferred stock, par value $0.0001 per share, issuable by the Board of Directors in one or more series without stockholder approval.

•

Cardinal Infrastructure Group Inc. acquired newly issued LLC units from Cardinal using the net proceeds of the IPO and became the sole managing member of Cardinal.

•

Cardinal Infrastructure Group Inc. issued 23,387,813 shares of Class B Common Stock to the Continuing Equity Holders, on a one-for-one basis with their LLC units, for nominal consideration.

In the accompanying condensed consolidated statements of changes in stockholders'/members' equity, the IPO Reorganization is reflected as: (i) the conversion of members’ equity to the recapitalized equity structure of Cardinal Infrastructure Group Inc. (Class A Common Stock, Class B Common Stock, and additional paid-in capital), (ii) the receipt of net IPO proceeds in exchange for newly issued LLC units, (iii) the recognition of noncontrolling interests representing the Continuing Equity Holders’ 61.0% economic interest in Cardinal, and (iv) the establishment of Cardinal Infrastructure Group Inc. as a reporting entity with the accompanying reclassification of the predecessor equity accounts.

Both the September 2025 Reorganization and the IPO Reorganization are accounted for as transactions among entities under common control. As Cardinal Infrastructure Group Inc. had no substantive operations prior to the IPO and the Continuing Equity Holders retained their majority economic interest (61.0%) in Cardinal, the Transactions are treated as a recapitalization rather than a business combination.

The September 2025 Reorganization, in which the pre-existing minority equity holders of Cardinal NC’s non-wholly owned subsidiaries exchanged their subsidiary-level interests for LLC units of Cardinal, was accounted for as an acquisition of noncontrolling interests in accordance with Accounting Standards Codification ("ASC") 810-10-45-23, with the carrying amounts of noncontrolling interests reclassified to members’ equity with no gain or loss recognized.

The IPO Reorganization, in which Cardinal Infrastructure Group Inc. became the sole managing member of Cardinal and completed the IPO, was accounted for as a recapitalization of the predecessor operating entity. The accompanying consolidated financial statements represent a continuation of the historical financial statements of Cardinal, with the exception of the recapitalized equity structure. Comparative information for periods prior to the Transactions reflects the historical financial statements of Cardinal.

Basis of Accounting

The accompanying condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The unaudited interim condensed consolidated financial statements include the results of the Company and its wholly owned or controlled subsidiaries. All significant intercompany transactions and balances have been eliminated during consolidation. In the opinion of management, the

condensed consolidated financial statements reflect all adjustments, which are necessary for the fair presentation of the financial condition, and results of operations for the interim periods presented.

The accompanying condensed consolidated financial statements were prepared in accordance with the requirements for interim financial information. Accordingly, these interim financial statements have not been audited and exclude certain disclosures required for annual financial statements. We have historically experienced, and in the future expect to continue to experience, variability in our results on a quarterly basis. Due to the seasonality of the Company's businesses, the operating results presented for interim periods are not necessarily indicative of the results that may be expected for any other interim period or for the entire year. These interim financial statements should be read in conjunction with the audited consolidated financial statements of the Company included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025.