SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* Ruppert Michael (Last) (First) (Middle) 50 MINUTEMAN ROAD (Street) ANDOVER MA 01810 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol MERCURY SYSTEMS INC [ MRCY ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner X Officer (give title below) Other (specify below) EVP, CFO and Treasurer
	3. Date of Earliest Transaction (Month/Day/Year) 02/16/2021
	4. If Amendment, Date of 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

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	02/16/2021		S		6,207(1)	D	$72.5434(2)	115,048	D

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 Securities Underlying Derivative Security (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: 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

Explanation of Responses:

1. Represents the number of shares required to be sold by the reporting person to cover tax withholding obligations in connection with the vesting of RSAs and PSAs. This sale was made to satisfy tax withholding obligations by a sell to cover transaction and does not represent a discretionary trade by the reporting person

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $72.32 to $72.70, inclusive.

Remarks:

	/s/ Michelle McCarthy, Attorney-in-Fact for Ruppert, Michael	02/18/2021
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* 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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

		LIMITED POWER OF ATTORNEY
FOR
MERCURY SYSTEMS, INC.
SECTION 16(a) FILINGS
Know all by these presents, that the undersigned
hereby constitutes and appoints each of
the Chief Financial Officer, the General Counsel,
and the Chief Accounting Officer of Mercury
Systems, Inc., acting singly, the undersigned's
true and lawful attorney-in-fact to:
(1)	prepare, execute in the undersigned's name
and on the undersigned's behalf, and submit to
the U.S. Securities and Exchange Commission (the
"SEC") a Faun ID, including amendments thereto,
and any other documents necessary or appropriate
to obtain codes and passwords enabling the
undersigned to make electronic filings with the
SEC of reports required by Section 16(a) of the
Securities Exchange Act of 1934, as amended (the
"Exchange Act"), or any rule or regulation of the
SEC;
(2)	execute for and on behalf of the
undersigned, in the undersigned's capacity as an
officer, director, and/or shareholder of Mercury
Systems, Inc. (the "Company"), Forms 3, 4, 5, and
144 and amendments thereto, in accordance with
Section 16(a) of the Exchange Act and the rules
thereunder;
(3)	do and perform any and all acts for and on
behalf of the undersigned which may be necessary
or desirable to complete and execute any such
Form 3, 4, 5 or 144, or amendments thereto, and
timely file such form with the SEC and any stock
exchange or similar authority; and
(4)	take any other action of any type
whatsoever which, in the opinion of such
attorney-in-fact, may be necessary or desirable
in connection with the foregoing authority, it
being understood that the documents executed by
each such attorney-in-fact on behalf of the
undersigned pursuant to this Limited Power of
Attorney shall be in such form and shall contain
such terms and conditions as such attorney-in-
fact may approve, provided, however, that the
undersigned does not grant to each such power-of-
attorney the right to engage in any transactions
involving the securities of the Company on behalf
of the undersigned, including without limitation,
the right to purchase or sell any securities of
the Company.
The undersigned hereby grants to each such
attorney-in-fact full power and authority to do'
and perform any and every act and thing
whatsoever requisite, necessary, or proper to be
done in the exercise of any of the rights and
powers herein granted, as fully to all intents
and purposes as the undersigned might or could do
if personally present, with full power of
substitution or revocation, hereby ratifying and
confirming all that each such attorney-in-fact,
or each such attorney-in-fact's substitute or
substitutes (any such substitute also being
referred to herein as an "attorney-in-fact"),
shall lawfully do or cause to be done by virtue
of this Limited Power of Attorney and the rights
and powers herein granted. The undersigned
acknowledges that each attorney-in-fact, in
serving in such capacity at the request of the
undersigned or such attorney-in-

fact, is not assuming, nor is the Company
assuming, any of the undersigned's
responsibilities to comply with Section 16 of the
Exchange Act.
The undersigned agrees that each such attorney-
in-fact shall not be liable for any error of
judgment or for any act done or omitted to be
done or for any mistake of fact or law except for
each such attorney-in-fact's own bad faith, and
the undersigned agrees to indemnify and to hold
each such attorney-in-fact harmless against any
loss, claim, damage, liability, or cost incurred
on each such attorney-in-fact's part arising out
of or in connection with acts undertaken or
omitted to be taken as an attorney-in-fact
hereunder.
This Limited Power of Attorney shall remain in
full force and effect until the undersigned is no
longer required to file Forms 3, 4, 5, and 144
with respect to the undersigned's holdings of and
transactions in securities of Mercury Systems,
Inc., unless earlier revoked by the
undersigned in a signed writing delivered to the
foregoing attorneys-in-fact. This Limited Power
of Attorney may be filed with the SEC as a
confirming statement of the authority granted
herein.
IN WITNESS WHEREOF, the undersigned has caused
this Limited Power of Attorney to be executed as
of this 5th day of February, 2018.

/s/ Michael Ruppert