Tutor Perini Corporation

Item 1.01. Entry into a Material Definitive Agreement. 6.625% Senior Notes due 2033 On July 2, 2026 (the “Closing Date”), Tutor Perini Corporation (the “Company”) completed the previously announced offering and sale of $400 million in aggregate principal amount of 6.625% Senior Notes due 2033 (the “Notes”) at an offering price of 100.000% (the “Notes Offering”). The Company is using the net proceeds from this offering, together with cash on hand, to redeem $400 million aggregate principal amount of the 11.875% Senior Notes due 2029 (the “2029 Notes”) and pay related premiums, accrued interest and fees and expenses associated with such redemption. The Company may temporarily invest amounts that are not immediately needed for these purposes in cash or cash equivalents or other short-term investments, including marketable securities. The Notes and related guarantees were offered and sold only to persons reasonably believed to be qualified institutional buyers in accordance with Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”), and, outside the United States, in compliance with Regulation S under the Securities Act. The Notes and related guarantees have not been registered under the Securities Act, or the securities laws of any other jurisdiction, and may not be offered or sold in the United States without registration or an applicable exemption from registration requirements. This report shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of the Notes and related guarantees in any state in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state. Indenture The terms of the Notes are governed by the indenture, dated as of the Closing Date (the “Indenture”), among the Company, the guarantors named therein (the “Guarantors”) and Wilmington Trust, National Association, as trustee (the “Trustee”). The Notes bear interest at a rate of 6.625% and mature on July 15, 2033. Interest is payable on the Notes on January 15 and July 15 of each year, commencing on January 15, 2027. The obligations of the Company under the Notes and the Indenture are, jointly and severally, unconditionally guaranteed on a senior unsecured basis by each existing and future wholly-owned subsidiary that guarantees the Company’s obligations under the Credit Agreement (as defined below). The Notes and the guarantees are the Company’s and the Guarantors’ senior unsecured obligations and rank equally in right of payment with the Company’s and the Guarantors’ existing and future senior unsecured obligations. The Notes and the guarantees are effectively subordinated to all of the Company’s and the Guarantors’ secured indebtedness, including the Credit Agreement (to the extent of the value of the collateral securing such indebtedness) and are structurally subordinated to all existing and future liabilities of each of the Company’s existing and future subsidiaries that do not guarantee the Notes. The Indenture contains restrictive covenants that limit the ability of the Company and its restricted subsidiaries to, among other things, incur additional indebtedness, make certain restricted payments, make investments, create liens or use assets as security in other transactions, effect mergers and consolidations, enter into transactions with affiliates, sell or transfer certain assets, and agree to certain restrictions on the ability of restricted subsidiaries to make payments to the Company. Certain of these covenants will be suspended if the Notes are assigned an investment grade rating from any two of S&P Global Ratings, Moody’s Investors Service, Inc. and Fitch Ratings, Inc. and no default or event of default has occurred and is continuing under the Indenture. The Indenture provides for events of default (subject in certain cases to customary grace and cure periods), which include, among others, nonpayment of principal or interest when due, breach of covenants or other agreements in the Indenture, defaults in payment of certain other indebtedness and certain events of bankruptcy or insolvency. Generally, if an event of default occurs, the Trustee or the holders of 30% in principal amount of the outstanding Notes may declare the principal of and accrued and unpaid interest on all of the Notes to be immediately due and payable. At any time prior to July 15, 2029, the Company may redeem the Notes in whole or in part at a redemption price equal to 100% of the principal amount of the Notes, plus accrued and unpaid interest, if any, to, but excluding, the date of redemption plus a “make-whole” premium, as set forth in the Indenture. At any time on or after July 15, 2029, the Company may redeem the Notes at the redemption prices set forth in the Indenture, plus accrued and unpaid interest, if any, to, but excluding, the redemption date. In addition, at any time prior to July 15, 2029, the Company may redeem up to 40% of the original aggregate principal amount of the Notes with the “net cash proceeds” of one or more equity offerings, as described in the Indenture, at a price equal to 106.625% of the aggregate principal amount thereof, plus accrued and unpaid interest, if any, to, but excluding, the redemption date. If the Company experiences certain change of control events, holders of the Notes may require it to repurchase all or part of their Notes at 101% of the principal amount thereof, plus accrued and unpaid interest, if any, to, but excluding, the repurchase date. Credit Agreement Amendment and Restatement On July 2, 2026, the Company entered into an amendment and restatement of its existing credit agreement (as amended and restated from time to time, the “Credit Agreement”) with BMO Bank N.A. (f/k/a BMO Harris Bank N.A.), as administrative agent and collateral agent, and each lender from time to time party thereto, that modified the terms of the existing revolving credit facility thereunder (the “Revolving Credit Facility”), including (a) extending the maturity of the Revolving Credit Facility to July 2, 2031, (b) increasing the commitments under the Revolving Credit Facility from $170.0 million to $350.0 million, (c) reducing the Adjusted Term Secured Overnight Financing Rate (SOFR) margin to a range between 1.75% and 2.50% based on a Total Net Leverage Ratio (compared to the previous range between 4.25% and 4.75% based on a First Lien Net Leverage Ratio) and eliminating the credit spread adjustment (10 bps), (d) reducing the base rate margin to a range between 0.75% and 1.50% based on a Total Net Leverage Ratio (compared to the previous range between 3.25% and 3.75% based on a First Lien Net Leverage Ratio), and (e) replacing the maximum First Lien Net Leverage Ratio financial maintenance covenant (of 2.25 to 1.00) with (1) a maximum Total Net Leverage Ratio of 3.50 to 1.00 and (2) a minimum cash Interest Coverage Ratio of 3.00 to 1.00. Capitalized terms used but not defined herein have the meanings ascribed to such terms in the Credit Agreement. The foregoing summaries of the Indenture and the amended and restated Credit Agreement are qualified in their entirety by reference to the Indenture and the Credit Agreement, copies of which are filed herewith as Exhibits 4.1 and 10.1, respectively, and incorporated by reference herein.

Item 2.03 Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant . The information set forth under Item 1.01 above is incorporated by reference into this Item 2.03.

Item 8.01 Other Events. On July 2, 2026, the Company redeemed all of the remaining outstanding 2029 Notes pursuant to the indenture governing the 2029 Notes, at a redemption price equal to 108.906% of the principal amount thereof (or $1,089.06 per $1,000.00 in principal amount), plus accrued and unpaid interest to, but excluding, the redemption date.