Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer,a non-accelerated filer, smaller reportingcompany, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complyingwith any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.oIndicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). YesoNox FORM 10-Q FOR THE QUARTER ENDED MARCH31, 2025 Organizational Structure The following diagram depicts our abbreviated organizational structure with references to the names of certain entities discussed inthis Quarterly Report on Form 10-Q. Unless the context requires otherwise, references to “NextDecade,” the “Company,” “we,” “us” and “our” refer to NextDecadeCorporation (NASDAQ: NEXT) and its consolidated subsidiaries, and references to “Rio Grande” refer to Rio Grande LNG, LLC and its NextDecade CorporationNotes to Consolidated Financial Statements Note 1 —Background and Basis of Presentation NextDecade Corporation, a Delaware corporation, is a Houston-based energy company primarily engaged in construction anddevelopment activities related to the liquefaction of natural gas and sale of LNG and the capture and storage of COemissions. We are2 constructing and developing a natural gas liquefaction and export facility located in the Rio Grande Valley near Brownsville, Texas (the “RioGrande LNG Facility”). The Rio Grande LNG Facility has received Federal Energy Regulatory Commission (“FERC”) approval and Department of Energy(“DOE”) FTA and non-FTA authorizations for the construction of up tofiveliquefaction trains and LNG exports totaling up to27milliontonnes per annum (“MTPA”). The Rio Grande LNG Facility hasthree liquefaction trains and related infrastructure (“Phase 1”) underconstruction, train4has achieved substantial commercial progress and is being advanced toward a final investment decision (“FID”), and train In March 2025, the U.S. Court of Appeals for the D.C. Circuit issued a revision to its August 2024 decision regarding our FERC order,resulting in a remand without vacatur of the FERC order for the first five liquefaction trains at the Rio Grande LNG Facility. The accompanying unaudited consolidated financial statements have been prepared in accordance with accounting principles generallyaccepted in the United States of America (“GAAP”) for interim financial information and with Rule 10-01 of Regulation S-X. Accordingly,they do not include all the information and disclosures required by GAAP for complete financial statements and should be read in conjunctionwith the consolidated financial statements and accompanying notes included in our Annual Report on Form 10-K for the year ended Certain reclassifications have been made to conform prior period information to the current presentation. The reclassifications did nothave a material effect on the Company’s financial position, results of operations or cash flows. Note 2 —Property, Plant and Equipment Property, plant and equipment consisted of the following (in thousands): Note 3 —Derivatives In July 2023, Rio Grande entered into interest rate swaps agreements (the “Swaps”) to protect against interest rate volatility byhedging a portion of the floating-rate interest payments associated with the credit facilities described in Note 6 —Debt. As of March31, 2025, Rio Grande has the following Swaps outstanding (in thousands): Table of Contents The Company values the Swaps using an income-based approach based on observable inputs to the valuation model including interestrate curves, risk adjusted discount rates, credit spreads and other relevant data. The net fair value of the Swaps is approximately $317.5million Note 4 —Leases The Company commenced the Rio Grande LNG Facility site lease on July 12, 2023 and it has an initial term of30years. TheCompany has the option to renew and extend the term of the lease for up totwoconsecutive renewal periods often yearseach, but as theCompany is not reasonably certain that those options will be exercised, none are recognized as part of our right of use assets and lease For the three months ended March 31, 2025 and 2024, our operating lease costs were $2.5million and $3.0million, respectively. Forthe three months ended March 31, 2025 and 2024, we paid approximately $1.9million and $2.1million, respectively, in cash for amounts Note 5 —Accrued Liabilities and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): Note 6 —Debt Debt consisted of the following (in thousands): Senior Secured Notes and Loans The6.67% Senior Secured Notes,6.85% Senior Secured Notes and6.58% Senior Secured Notes (col