Edgar Filing: Brown Robert S.

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 ^*

Brown Robert S.

2. Issuer Name and Ticker or Trading Symbol
NxStage Medical, Inc. [NXTM]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

_____ Director	_____ 10% Owner
__X__ Officer (give title below)	_____ Other (specify below)
Sr. Vice President, CFO

(Last)

(First)

(Middle)

C/O NXSTAGE MEDICAL, INC., 350 MERRIMACK STREET

3. Date of Earliest Transaction (Month/Day/Year)
12/31/2012

(Street)

LAWRENCE, MA 01843

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)
1.Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	12/31/2012		M		11,981 ⁽¹⁾	A	$ 0	27,116	D
Common Stock	12/31/2012		F⁽²⁾		3,798	D	$ 11.25	23,318	D

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

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Restricted Stock Unit

⁽³⁾

12/31/2012

11,981

⁽⁴⁾

Common Stock

11,981

$ 0

Reporting Owners

Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
Brown Robert S. C/O NXSTAGE MEDICAL, INC. 350 MERRIMACK STREET LAWRENCE, MA 01843			Sr. Vice President, CFO

Signatures

/s/ Winifred L. Swan, attorney-in-fact		01/03/2013
^**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)	Shares of common stock acquired upon the vesting of restricted stock units.
(2)	This transaction reflects the withholding of shares of the Company's common stock to satisfy the reporting person's tax liability incurred in connection with the final tranche of awards granted to the reporting person on March 8, 2011 pursuant to the Company's 2010 Performance Share Plan.
(3)	Each restricted stock unit represents a contingent right to receive one share of the Company's common stock.
(4)	In March 2010, the Compensation Committee established the Company's 2010 Performance Share Plan with the amount of awards to be determined based upon the satisfaction of 2010 revenue and cash consumption targets. On March 8, 2011, the Compensation Committee granted the reporting person 35,945 restricted stock units based on its evaluation of the achievement of performance criteria under the Company's 2010 Performance Share Plan. The award vested 33 1/3rd% on the date of grant (March 8, 2011), with the balance vesting in two equal installments on December 31, 2011 and December 31, 2012.

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