Estimation Uncertainty and Accounting policy judgments

Impairment of investments in associates and joint ventures

The application of the Company’s accounting policy for impairment assessment of its investments in associates and joint ventures requires significant judgment to determine whether objective evidence of impairment exists. The investment in Cauchari-Olaroz includes the Company’s equity-accounted investments in associates, Minera Exar and Exar Capital, which are equity investees holding interests in the underlying Cauchari-Olaroz project. The Company’s interest in Sal de la Puna is considered a joint venture and is accounted for using the equity method.

Management’s assessment of whether objective evidence of impairment exists considers whether any events have impacted estimated future cash flows (loss events) or if there is any information regarding significant changes with an adverse effect on the investments in associates and joint ventures. These considerations include (i) significant financial difficulties of the associates and joint ventures; (ii) a breach of contract, such as default or delinquency in payments by the associates and joint ventures; (iii) changes in the development plan or strategy for the underlying Cauchari-Olaroz or Sal de la Puna; or (iv) changes in significant assumptions that drive the valuation of the underlying Cauchari-Olaroz or Sal de la Puna, including forecasted commodity prices, reserve and resource estimates, and capital expenditure requirements.

Management has performed an assessment and concluded that no objective evidence of impairment exists as of December 31, 2025.

Impairment of Exploration and Evaluation Assets

The application of the Company’s accounting policy for impairment of exploration and evaluation assets requires judgment to determine whether indicators of impairment exist, including information such as, the period for which the Company has the right to explore including expected renewals, whether substantive expenditures on further exploration and evaluation of resource properties are budgeted and evaluation of the results of exploration and evaluation activities up to the reporting date. Management has performed an impairment indicator assessment on the Company’s exploration and evaluation assets and has concluded that no impairment indicators exist as of December 31, 2025.

Accounting for Joint Arrangements

A joint arrangement is defined as an arrangement over which two or more parties have joint control, which is the contractually agreed sharing of control. Joint control exists only when decisions about the relevant activities (those that significantly affect the returns of the arrangement) require unanimous consent of the parties sharing control. There are two types of joint arrangements: joint operations and joint ventures.

A joint operation is a joint arrangement where the parties with joint control have rights to the assets and are responsible for funding the liabilities related to the arrangement. The Company recognizes its share of the assets, liabilities, revenues, and expenses of a joint operation. A joint venture is a joint arrangement where the parties with joint control have rights to the net assets of the arrangement. Investments in joint ventures are accounted for using the equity method.

The Company’s 65% ownership interest in Sal de la Puna is considered to be a joint venture and accounted for using the equity method (Note 6).

Fair value of derivatives

The fair values of financial instruments that are not traded in an active market are determined using valuation techniques. The valuation of the convertible notes embedded derivative liability required management to make significant estimates. Management exercises judgment in selecting the appropriate valuation method and in making estimates of specific model inputs based on conditions existing at the reporting date.

The valuation of the convertible note embedded derivatives was performed using a partial differential equation method with Monte Carlo simulation, which required significant assumptions, including expected volatility of traded instruments, credit spreads, and estimates related to other inputs.

Refer to Note 13 for further details on the methods and assumptions used in the measurement of the convertible note embedded derivatives.

Determination of Commercial Production for the Cauchari Olaroz project

Judgment is a requirement in determining whether a project’s assets are available for use (referred to as “commercial production”). In making this determination, management considers specific facts and circumstances, including, but not limited to, whether the product produced by the plant is saleable, the completion of a reasonable commissioning period, and the achievement of consistent operating results at a predetermined level of design capacity for a reasonable period of time.

Minera Exar determined that commercial production was achieved at the Cauchari-Olaroz project as of October 1, 2024. As a result, the project’s assets were considered ready for their intended use, and depreciation of these assets commenced on October 1, 2024.

The following is the condensed financial information of Sal de la Puna Holdings S.a.r.l. on a 100% basis.

The following is the condensed financial information of Exar Capital on a 100% basis.

The Convertible Notes represent financial instruments that include a debt host accounted for at amortized cost, and a conversion option and a redemption option derivative, which are separated from the debt host and accounted for at fair value, with changes in fair value recorded in the statement of comprehensive loss. These derivatives are accounted for together as a single compound derivative when separated from the debt host.

On January 23, 2025, the Company completed the Continuation from Canada to Switzerland. As a result of the Continuation, Lithium Argentina's shares were established with a nominal par value of $0.01 per share, resulting in share capital of $1,619 and a capital reserve of $1,499,682. The number of shares outstanding remained unchanged.

The share capital is fully paid-in, meaning that the entire issue price of the shares has been fully paid to Lithium Argentina. Lithium Argentina has one class of shares outstanding, being the Common Shares. The Common Shares are not convertible into shares of any other class or series.

Equity Incentive Plan

The Company has an equity incentive plan (the “Plan”) whereby, from time to time at the discretion of the Board of Directors, eligible directors, officers, employees and consultants are awarded restricted share units (“RSUs”) and performance share units (“PSUs”) that convert automatically into common shares upon vesting, subject to any applicable deferral provisions under the terms of the Plan. In addition, independent directors are awarded deferred share units (“DSUs”), generally as partial compensation for their services as directors. DSUs may be redeemed by directors for common shares upon retirement or termination from the Board.

The Plan also permits the grant of incentive stock options exercisable to purchase common shares of the Company (“stock options”). The Plan is a “rolling plan”, under which the aggregate number of common shares to be issued shall not exceed 8% of the outstanding shares from time to time.

Restricted Share Units

During the year ended December 31, 2025, the Company granted 4,529 RSUs (2024 – 1,913) to its employees and consultants. The total estimated fair value of the RSUs granted was $12,560 (2024 – $7,346) based on the market value of the Company’s shares on the grant date. Subsequent to year-end, the Company granted 1,405 RSUs to employees and consultants in lieu of annual performance bonuses, with an estimated fair value of $10,859 based on the market price of the Company’s shares on the grant date.

As at December 31, 2025, there was $8,678 (2024 – $6,969) of total unamortized compensation cost relating to unvested RSUs. During the year ended December 31, 2025, equity compensation expense related to RSUs of $11,027 was recognized in expenses (2024 – $3,118).

Deferred Share Units

During the year ended December 31, 2025, the Company granted 324 DSUs (2024 – 203) with a total estimated fair value of $900 (2024 – $780).

Stock Options

During the year ended December 31, 2025, no stock options were granted by the Company (2024 – 1,225). None of the stock options were exercisable as at December 31, 2025.

As at December 31, 2025, there was $1,368 (2024 – $4,179) of total unamortized compensation cost relating to unvested stock options. During the year ended December 31, 2025, stock-based compensation expense related to stock options of $2,811 (2024 – $3,285) was recognized in operating expenses on the statement of comprehensive loss.

Performance Share Units

During the year ended December 31, 2025, the Company did not grant any PSUs (2024 – none). As at December 31, 2025, there was $108 (2024 – $412) of total unamortized compensation cost relating to unvested PSUs.

During the year ended December 31, 2025, equity compensation expense related to PSUs of $304 was charged to operating expenses (2024 – $554).

A summary of changes to the number of outstanding RSUs is as follows: