MP

Represents deferred stock units ("DSUs") awarded in connection with the election to defer cash retainers by the reporting person. Each DSU represents a right to receive a share of the registrant's common stock and are fully vested on grant. The DSUs will be settled upon the earlier to occur of the following: (i) June 15th occurring following the close of the fifth calendar year following the close of the calendar year in which the cash retainers are earned; (ii) certain changes in control of the registrant; and (iii) the date of the reporting person's separation from service.

Restricted stock units convert into common stock on a one-for-one basis.

On November 17, 2020, the reporting person was granted 3,998 restricted stock units, which vested on June 1, 2021, and the reporting person's receipt of the shares of common stock was deferred until June 15, 2026.

On November 17, 2020, the reporting person was granted 3,998 restricted stock units, which vested on June 1, 2021, and the reporting person's receipt of the shares of common stock was deferred until June 15, 2026.

Restricted stock units convert into common stock on a one-for-one basis.

On November 17, 2020, the reporting person was granted 3,998 restricted stock units, which vested on June 1, 2021, and the reporting person's receipt of the shares of common stock was deferred until June 15, 2026.

Restricted stock units convert into common stock on a one-for-one basis.

Restricted stock units convert into common stock on a one-for-one basis.

On November 17, 2020, the reporting person was granted 3,998 restricted stock units, which vested on June 1, 2021, and the reporting person's receipt of the shares of common stock was deferred until June 15, 2026.

Restricted stock units convert into common stock on a one-for-one basis.

Each restricted stock unit ("RSU") represents a contingent right to receive one share of MP Materials Corp. ("Issuer") common stock. These RSUs vest on the earlier of: (i) June 15, 2027; and (ii) the next annual meeting of the Issuer's stockholders, subject to the reporting person's continued service through the applicable vesting date, and settled upon the earlier to occur of (x) June 15th following the fifth anniversary of the vesting date; (y) a "change in control event" within the meaning of Section 409A of the Internal Revenue Code; and (z) the date of the director's separation from service. These RSUs fully vest upon a change in control of the Issuer or the director's termination of service due to death or disability.

Each restricted stock unit ("RSU") represents a contingent right to receive one share of MP Materials Corp. ("Issuer") Class A common stock. These RSUs vest on the earlier of: (i) June 15, 2027; and (ii) the next annual meeting of the Issuer's stockholders, subject to the reporting person's continued service through the applicable vesting date, and settled upon the earlier to occur of (x) June 15th following the fifth anniversary of the vesting date; (y) a "change in control event" within the meaning of Section 409A of the Internal Revenue Code; and (z) the date of the director's separation from service. These RSUs fully vest upon a change in control of the Issuer or the director's termination of service due to death or disability.

Each restricted stock unit ("RSU") represents a contingent right to receive one share of MP Materials Corp. ("Issuer") common stock. These RSUs vest on the earlier of: (i) June 15, 2027; and (ii) the next annual meeting of the Issuer's stockholders, subject to the reporting person's continued service through the applicable vesting date, and settled upon the earlier to occur of (x) June 15th following the fifth anniversary of the vesting date; (y) a "change in control event" within the meaning of Section 409A of the Internal Revenue Code; and (z) the date of the director's separation from service. These RSUs fully vest upon a change in control of the Issuer or the director's termination of service due to death or disability.

Each restricted stock unit ("RSU") represents a contingent right to receive one share of MP Materials Corp. ("Issuer") Class A common stock. These RSUs vest on the earlier of: (i) June 15, 2027; and (ii) the next annual meeting of the Issuer's stockholders, subject to the reporting person's continued service through the applicable vesting date, and settled upon the earlier to occur of (x) June 15th following the fifth anniversary of the vesting date; (y) a "change in control event" within the meaning of Section 409A of the Internal Revenue Code; and (z) the date of the director's separation from service. These RSUs fully vest upon a change in control of the Issuer or the director's termination of service due to death or disability.

Each restricted stock unit ("RSU") represents a contingent right to receive one share of MP Materials Corp. ("Issuer") common stock. These RSUs vest on the earlier of: (i) June 15, 2027; and (ii) the next annual meeting of the Issuer's stockholders, subject to the reporting person's continued service through the applicable vesting date, and settled upon the earlier to occur of (x) June 15th following the fifth anniversary of the vesting date; (y) a "change in control event" within the meaning of Section 409A of the Internal Revenue Code; and (z) the date of the director's separation from service. These RSUs fully vest upon a change in control of the Issuer or the director's termination of service due to death or disability.

Each restricted stock unit ("RSU") represents a contingent right to receive one share of MP Materials Corp. ("Issuer") Class A common stock. These RSUs vest on the earlier of: (i) June 15, 2027; and (ii) the next annual meeting of the Issuer's stockholders, subject to the reporting person's continued service through the applicable vesting date, and settled upon the earlier to occur of (x) June 15th following the fifth anniversary of the vesting date; (y) a "change in control event" within the meaning of Section 409A of the Internal Revenue Code; and (z) the date of the director's separation from service. These RSUs fully vest upon a change in control of the Issuer or the director's termination of service due to death or disability.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $71.00 to $71.81. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (1) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $68.27 to $69.25. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (4) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $70.00 to $70.98. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (3) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $64.09 to $65.09. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (10) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $65.10 to $65.23. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (9) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $68.13 to $68.29. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (4) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $65.14 to $66.12. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (7) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $66.13 to $67.12. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (6) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $64.13 to $65.12. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (8) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $67.13 to $68.12. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (5) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $65.00 to $65.80. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (3) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $66.00 to $66.19. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (1) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $65.10 to $65.60. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (4) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $64.10 to $65.09. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (5) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $67.00 to $67.46. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (1) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $65.50 to $65.94. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (3) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 16, 2025.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $75.00 to $75.09. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 20, 2025.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 16, 2025.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $64.00 to $64.24. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (4) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 16, 2025.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $64.00 to $64.28. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.

James Litinsky as sole trustee of the James Henry Litinsky, Trustee of James Henry Litinsky Revocable Trust u/a/d 10/19/2011.

Represents shares withheld to satisfy tax withholding obligations applicable to the vesting of restricted stock units that vested on April 1, 2026.

Represents deferred stock units ("DSUs") awarded in connection with the election to defer cash retainers by the reporting person. Each DSU represents a right to receive a share of the registrant's common stock and are fully vested on grant. The DSUs will be settled upon the earlier to occur of the following: (i) June 15th occurring following the close of the fifth calendar year following the close of the calendar year in which the cash retainers are earned; (ii) certain changes in control of the registrant; and (iii) the date of the reporting person's separation from service.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 16, 2025.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $60.00 to $60.06. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 20, 2025.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $60.00 to $60.10. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.

Represents shares withheld to satisfy tax withholding obligations applicable to the vesting of restricted stock units that vested on January 22, 2026.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on February 26, 2025.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $68.00 to $68.55. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.

Represents shares withheld to satisfy tax withholding obligations applicable to the vesting of restricted stock units that vested on January 14, 2026.

Represents shares withheld to satisfy tax withholding obligations applicable to the vesting of restricted stock units that vested on January 14, 2026.

Represents shares withheld to satisfy tax withholding obligations applicable to the vesting of restricted stock units that vested on January 14, 2026.

Represents shares withheld to satisfy tax withholding obligations applicable to the vesting of restricted stock units that vested on January 13, 2026.

Represents shares withheld to satisfy tax withholding obligations applicable to the vesting of restricted stock units that vested on January 13, 2026.

Represents shares withheld to satisfy tax withholding obligations applicable to the vesting of restricted stock units that vested on January 13, 2026.

Represents shares withheld to satisfy tax withholding obligations applicable to the vesting of restricted stock units that vested on January 13, 2026.