Washington, D.C. 20549


Pursuant to Section 13 or 15(d) of
The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): May 25, 2017

(Exact name of registrant as specified in its charter)

(State or other jurisdiction of incorporation)
(Commission File Number)
(I.R.S. Employer Identification No.)
350 Merrimack Street, Lawrence, MA
(Address of principal executive offices)
(Zip Code)

(978) 687-4700
(Registrant's telephone number, including area code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

o Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))
Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company o

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  o

Explanatory Note
The sole purpose of this amendment is to disclose, pursuant to Item 5.07(d) of Form 8-K, how frequently NxStage Medical, Inc. (“NxStage”) will conduct future advisory stockholder votes on its named executive officers’ compensation (“say-on-pay votes”).

Item 5.07 Submission of Matters to a Vote of Security Holders.
On May 25, 2017, NxStage held its 2017 Annual Meeting of Stockholders at which stockholders, among other actions, conducted an advisory vote on the frequency of future say-on-pay votes. As previously reported, a majority of the votes cast on this proposal were cast in favor of holding such say-on-pay votes annually. In light of these voting results, NxStage will continue to conduct a say-on-pay vote annually. The next advisory stockholder vote on the frequency of future say-on-pay votes will occur no later than NxStage’s 2023 Annual Meeting of Stockholders.

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

NxStage Medical, Inc.

By: /s/ Winifred L. Swan    
Winifred L. Swan
General Counsel    
Date: October 6, 2017