Ownership Submission
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, Section 17(a) of the Public Utility Holding Company Act of 1935 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 *
Shelnitz Mark A
  2. Issuer Name and Ticker or Trading Symbol
W R GRACE & CO [GRA]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Sr. VP, GC and Secretary
(Last)
(First)
(Middle)
C/O W. R. GRACE & CO., 7500 GRACE DRIVE
3. Date of Earliest Transaction (Month/Day/Year)
02/22/2019
(Street)

COLUMBIA, MD 21044
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, par value $0.01 per share 02/22/2019   M   1,323 (1) A (2) 61,238 D  
Common Stock, par value $0.01 per share 02/22/2019   F   672 D $ 77.65 60,566 D  
Common Stock, par value $0.01 per share 02/25/2019   M   912 (3) A (2) 61,478 D  
Common Stock, par value $0.01 per share 02/25/2019   F   439 D $ 77.93 61,039 D  
Common Stock, par value $0.01 per share 02/25/2019   A   6,572 A $ 0 67,611 D  
Common Stock, par value $0.01 per share 02/25/2019   F   3,150 D $ 77.93 64,461 D  
Common Stock, par value $0.01 per share               12,097 I By Trust (4)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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
Restricted Stock Units (5) 02/22/2019   M     1,323   (1)   (1) Common Stock 1,323 $ 0 2,915 D  
Employee Stock Options (rights to buy) $ 78.115 02/25/2019   A   7,569     (6) 02/25/2029 Common Stock 7,569 $ 0 7,569 D  
Restricted Stock Units (5) 02/25/2019   A   1,760     (7)   (7) Common Stock 1,760 $ 0 4,675 D  
Restricted Stock Units (5) 02/25/2019   M     912   (3)   (3) Common Stock 912 $ 0 3,763 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Shelnitz Mark A
C/O W. R. GRACE & CO.
7500 GRACE DRIVE
COLUMBIA, MD 21044
      Sr. VP, GC and Secretary  

Signatures

 /s/ Sean E. Dempsey, Attorney-in-Fact   02/26/2019
**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) On February 23, 2017, the reporting person was granted 1,926 stock units, vesting annually in three substantially equal installments beginning on February 23, 2018, 642 of these stock units vested and settled on February 22, 2019. On February 22, 2018, the reporting person was granted 2,042 stock units, vesting in three substantially equal installments beginning on February 22, 2019, 681 of these stock units vested and settled on that date.
(2) Restricted stock units converted into Common Stock on a one-for-one basis.
(3) On February 25, 2016, the reporting person was granted 2,738 stock units, vesting annually in three substantially equal installments beginning on February 24, 2017, 912 of these stock units vested and settled on February 25, 2019.
(4) Such shares are held in a trust established by the issuer for the benefit of certain officers and directors.
(5) Each Restricted Stock Unit represents a contingent right to receive one share of Common Stock or at the Issuer's election, the cash value thereof.
(6) Options become exercisable in three substantially equal annual installments beginning on February 25, 2020.
(7) Restricted Stock Units vest in three substantially equal annual installments beginning on February 25, 2020, and will be settled within 60 days of those vesting dates.

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