FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
King Elizabeth
   2. Issuer Name and Ticker or Trading Symbol
QUANTUM CORP /DE/ [QMCO] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Chief Revenue Officer
(Last)
(First)
(Middle)
C/O QUANTUM CORPORATION, 224 AIRPORT PARKWAY, SUITE 550		 3. Date of Earliest Transaction (Month/Day/Year)
03/11/2021
(Street)

SAN JOSE, CA 95110		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock (1) 03/11/2021   M   6,875 A $ 0 310,008 (2) D  

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Performance-Based Restricted Stock Units (1) 03/11/2021   M     6,875   (1) 07/01/2025 Common Stock 6,875.00 $ 0 6,875 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
King Elizabeth
C/O QUANTUM CORPORATION
224 AIRPORT PARKWAY, SUITE 550
SAN JOSE, CA 95110		       Chief Revenue Officer  

Signatures

 /s/ Josie Buensuceso, Attorney-in-Fact for Elizabeth King   03/17/2021
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Performance-Based Restricted Stock Units were previously reported on July 2, 2020, which vest in two equal components upon the later of achievement of specified levels of the average closing prices of a share of QMCO common stock during any hundred (100) calendar day period, and upon specified service dates, whichever is later. The first achievement date occurred on March 11, 2021, as certified by the leadership and compensation committee of QMCO, resulting in 6,875 units meeting the appropriate performance-based conditions. However, these shares remain subject to time-based vesting conditions and will therefore vest on January 1, 2022, subject to continued employment. These shares are reflected on Table I, and 6,875 units remaining subject to these performance-based and time-based vesting conditions.
(2) Includes 5,977 shares acquired under Quantum Corporation's Employee Stock Purchase Plan on February 5, 2021.

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