MP Materials (MP) 8-K Settlement Method Election Notice

Exhibit 99.1

SETTLEMENT METHOD ELECTION NOTICE

MP Materials Corp.

0.25% Convertible Senior Notes due 2026

CUSIP 553368 AA9

March 20, 2024

U.S. Bank Trust Company, National Association

60 Livingston Ave

Saint Paul, MN 55107

Attn: Corporate Trust Administrator for MP Materials Corp.

AND

Holders of MP Materials Corp.’s 0.25% Convertible Senior Notes due 2026

Re: Election of Settlement Method

Reference is hereby made to the Indenture (the “Indenture”), dated as of March 26, 2021, between MP Materials Corp. (the “Company”) and U.S. Bank Trust Company, National Association (as successor in intertest to U.S. Bank National Association), as Trustee, relating to the 0.25% Convertible Senior Notes due 2026 (the “Notes”) of the Company. Capitalized terms used but not defined herein have the meanings given to such terms in the Indenture. Pursuant to Section 14.02(a)(vi) of the Indenture, the Company hereby irrevocably elects Combination Settlement with a Specified Dollar Amount per $1,000 principal amount of Notes equal to $1,000, with respect to any Conversion Dates occurring on or after the date hereof.

Sincerely,

MP MATERIALS CORP.

By: /s/ Elliot D. Hoops

Name: Elliot D. Hoops

Title: General Counsel and Secretary