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    <dei:AmendmentDescription contextRef="P01_01_2025To12_31_2025" id="ixv-176">Lithium Americas Corp. (&#x201c;LAC&#x201d; or the &#x201c;Company&#x201d;) is filing this Amendment No.&#160;1 on Form 10-K/A for the year ended December&#160;31, 2025 (the &#x201c;Form 10-K/A&#x201d;) to amend our Annual Report on Form 10-K for the year ended December&#160;31, 2025, originally filed with the Securities and Exchange Commission (the &#x201c;SEC&#x201d;) on March&#160;19, 2026 (the &#x201c;Original Form 10-K&#x201d;). We are filing this Form 10-K/A to, among other things, present the information required by Part III of Form 10-K that was previously not included in the Original Form 10-K in reliance on General Instruction G.(3) to Form 10-K. The Company is hereby amending the Original Form 10-K as follows: On the cover page, (i)&#160;to delete the reference in the Original Form 10-K to the incorporation by reference of the Company&#x2019;s definitive proxy statement for its 2026 annual meeting of stockholders (the &#x201c;Annual Meeting&#x201d;) and (ii)&#160;to update the date as of which the number of outstanding shares of the Company&#x2019;s common stock is being provided; &#x2022;To present the information required by Part III of Form 10-K, which information we originally indicated in the Original Form 10-K would be incorporated by reference in our definitive proxy statement to be delivered to our stockholders in connection with our Annual Meeting; and &#x2022;To file new certifications of the Company&#x2019;s principal executive officer and principal financial officer as Exhibits 31.3 and 31.4 to this Form&#160;10-K/A under Item 15 of Part IV hereof, pursuant to Rule 12b-15 under the Securities Exchange Act of 1934, as amended (the &#x201c;Exchange Act&#x201d;). Because no financial statements have been included in this Form 10-K/A and this Form 10-K/A does not contain or amend any disclosure with respect to Items 307 and 308 of Regulation S-K, paragraphs 3, 4, and 5 of the certifications have been omitted. Except as described above, no other changes have been made to the Original Form 10-K. This Form 10-K/A does not otherwise update information in the Original Form 10-K to reflect facts or events occurring subsequent to the filing date of the Original Form 10-K. This Form&#160;10-K/A should be read in conjunction with the Original Form 10-K and with any of our filings made with the SEC subsequent to filing of the Original Form 10-K. </dei:AmendmentDescription>
    <ecd:InsiderTrdPoliciesProcAdoptedFlag contextRef="P01_01_2025To12_31_2025" id="ixv-6936">true</ecd:InsiderTrdPoliciesProcAdoptedFlag>
    <ecd:AwardTmgMnpiDiscTextBlock contextRef="P01_01_2025To12_31_2025" id="ixv-3791">&lt;div style="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:ARIAL"&gt;&lt;div style="color:#3a7ca3;display:inline;"&gt;&lt;div style="font-weight:bold;display:inline;"&gt;Policies and Practices Related to the Grant of Certain Equity Awards in Relation to the Release of Material Nonpublic Information &lt;/div&gt;&lt;/div&gt;&lt;/div&gt;&lt;div style="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:ARIAL"&gt;LAC does not currently grant stock options or option-like equity awards to the Company&#x2019;s executive officers, employees or directors, therefore LAC does not currently have a formal practice or policy with respect to the grant of stock options or option-like awards. &lt;/div&gt;</ecd:AwardTmgMnpiDiscTextBlock>
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