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 *
POPIK WILLAIM C MD
  2. Issuer Name and Ticker or Trading Symbol
Darwin Professional Underwriters Inc [DR]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
9 FARM SPRINGS ROAD
3. Date of Earliest Transaction (Month/Day/Year)
05/19/2006
(Street)

FARMINGTON, CT 06032
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 05/19/2006   A   151.52 A $ 0 151.52 (1) D  
Common Stock 05/19/2006   P   354.55 A $ 264 506.07 (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
Share Units (3) 05/19/2006   A   246.24     (4)   (4) Common Stock 246.24 (5) 246.24 (6) D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
POPIK WILLAIM C MD
9 FARM SPRINGS ROAD
FARMINGTON, CT 06032
  X      

Signatures

 Melanie Wilhelm (attorney-in-fact)   05/23/2006
**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) Amount reflected does not give effect to a 33-for-two stock split that will be effective upon the completion of the initial public offering of Darwin Professional Underwriters, Inc. (the "stock split"). After giving effect to the stock split, the amount would be 2,500 shares of Common Stock.
(2) Amount reflected does not give effect to the stock split. After giving effect to the stock split, the amount would be 8,350 shares of Common Stock.
(3) 1-for-1
(4) The share units were credited under the Stock and Unit Plan for Non-Employee Directors (the "Plan") of Darwin Professional Underwriters, Inc. (the "Company") and will be paid in either cash or in shares of the Company's common stock (the "Common Stock") or some combination thereof at the discretion of the Board of Directors of the Company based on the Fair Market Value (as defined in the Plan) of the Common Stock on the first business day following the earlier of (i) the date that is five calendar years following the calendar year in which the reporting person's fees were originally converted to share units, and (ii) the date the reporting person ceases to be a member of the Board of Directors of the Company or of a "change in control" (as defined in the Plan).
(5) Not applicable
(6) Amount reflected does not give effect to the stock split. After giving effect to the stock split, the amount would be 4,063 share units.

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