EY Consent ESPP 2015

We consent to the incorporation by reference in the Registration Statement (Form S-8) pertaining to the 2005 Employee Stock Purchase Plan of NxStage Medical, Inc. of our reports dated February 26, 2015, with respect to the consolidated financial statements of NxStage Medical, Inc. and the effectiveness of internal control over financial reporting of NxStage Medical, Inc. included in its Annual Report (Form 10-K) for the year ended December 31, 2014, filed with the Securities and Exchange Commission.