Stock Option Agreement
Granted Under NxStage Medical, Inc. 2014 Omnibus Incentive Plan

1.
Grant of Option.

This agreement evidences the grant by NxStage Medical, Inc., a Delaware
corporation (“Company”), to the Grantee listed below of an option to purchase
shares of the Company’s Stock (“Shares”), as outlined below:

Grantee: <first_name> <middle_name> <last_name>
Shares: <shares_awarded>
Option Price per Share: <award_price>
Option Type: <award_type_code>
Grant Date: <award_date>
Final Exercise Date: 5:00 p.m. ET on <expire_date>

Except as otherwise indicated by the context, “Grantee” shall be deemed to
include any person who acquires the right to exercise this option validly under
its terms. If the Option Type listed above is “Non-qualified Stock Option” or
“NQ,” then this option shall not be an incentive stock option as defined in
Section 422 of the Code. If the Option Type listed above is “Incentive Stock
Option” or “ISO,” then this option is intended to qualify as an incentive stock
option as defined in Section 422 of the Code. Notwithstanding the foregoing, if
the Grantee ceases to be an Employee of the Company or any corporate Subsidiary
but continues to provide Service, this option will be deemed a Non-qualified
Stock Option as of the date 3 months and 1 day after the Grantee ceases to be an
Employee of the Company or any corporate Subsidiary. In addition, to the extent
that all or part of an option intended to be an “Incentive Stock Option” exceeds
the “$100,000 per year limitation” rule of Section 422(d) of the Code, the
option or the lesser excess part will be deemed to be a Non-qualified Stock
Option.

This option is granted in consideration of Service rendered and to be rendered
by the Grantee to the Company or an Affiliate. This option is subject to the
terms of this agreement, including any specific provisions for the Grantee’s
country in the attached Schedule B, and the Company’s 2014 Omnibus Incentive
Plan (“Plan”), a copy of which is furnished to the Grantee with this agreement.
Any capitalized term that is not defined in this agreement shall have the
meaning ascribed to it in the Plan.

2.
Vesting Schedule.

This option will become exercisable (“vest”) for the Shares and on the dates
indicated on Schedule A to this agreement, provided that the Grantee continues
to provide Service to the Company or an Affiliate on such dates and has provided
Service at all times since the Grant Date.

3.
Exercise of Option.

(a)
Right of Exercise. The Grantee’s right of exercise will be cumulative so that to
the extent this option is not exercised in any period to the maximum extent
permissible, this option will continue to be exercisable with respect to any
remaining Shares for which it is vested until this option terminates. No partial
exercise of this option may be for any fractional Share or for fewer than ten
whole Shares.

    
(b)
Form of Exercise. Each election to exercise this option must be in writing on
the form specified by the Company and received by the Company at its principal
office.

(c)
Payment of Option Price and Withholding Taxes. The Grantee must pay to the
Company the Option Price and, if the Grantee is an Employee, all applicable
federal, state, local or foreign withholding taxes required by law to be
withheld in respect of this option or the Shares:

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•
in cash;

•
by delivery (on a form acceptable to the Company) of an irrevocable direction to
a licensed securities broker acceptable to the Company to sell Shares and to
deliver proceeds from such sale to the Company in payment of the Option Price
and all applicable withholding taxes; or

•
if the Grantee is a director or officer of the Company subject to Section 16 of
the Exchange Act, by tender or attestation of unencumbered shares of the
Company’s Stock equal in value to the Option Price and all applicable
withholding taxes (including by means of a net exercise directly with the
Company).

Not all forms and methods of payment are available in every country. In
addition, the Company may deduct from payments of any kind otherwise due to the
Grantee the Option Price and all applicable withholding taxes in respect of this
option or the Shares. The Company may, in its discretion, permit the Grantee to
make alternative arrangements for payment of such amounts. The Grantee
understands that the Grantee (and not the Company) shall be responsible for the
Grantee’s own tax liability that may result from this investment or the
transactions contemplated by this agreement.

(d)
Issued Shares. All Shares will be issued in the name of the Grantee in book
entry form only.

4.
Termination – Employees and Consultants.

The termination provisions in this section apply to Grantees who are Employees
of, or consultants or advisors to (excluding Outside Directors), the Company or
an Affiliate as of the Grant Date.

(a)
Continuous Relationship with the Company or an Affiliate Required. Except as
otherwise provided in this section, this option will terminate on the earlier of
(1) the Grantee ceasing to provide Service to the Company or an Affiliate for
any reason and (2) the Final Exercise Date.

(b)
Death or Disability. If the Grantee ceases to provide Service due to his or her
death or disability (within the meaning of Section 22(e)(3) of the Code) and the
Company has not terminated the Grantee for Cause, this option will terminate on
the earlier of (1) 5:00 p.m. ET on the date that is exactly 1 year after the
Grantee ceases to provide Service due to his or her death or disability and (2)
the Final Exercise Date.

(c)
Certain Other Terminations. If the Grantee ceases to provide Service for any
reason other than due to his or her death or disability (within the meaning of
Section 22(e)(3) of the Code) and the Company has not terminated the Grantee for
Cause, this option will terminate on the earlier of (1) 5:00 p.m. ET on the date
that is exactly 3 months after the Grantee ceases to provide Service and (2) the
Final Exercise Date. Notwithstanding the foregoing, if the Grantee violates the
non-competition, confidentiality or non-solicitation provisions of any
employment contract, confidentiality and nondisclosure agreement, or other
agreement between the Grantee and the Company, this option will terminate
immediately upon such violation.

5.
Termination – Directors.

The termination provisions in this section apply to Grantees who are Outside
Directors of the Company as of the Grant Date.

(a)
3+ Years of Service. If the Grantee ceases to provide Service and at such time
has completed three or more full years of Service as a member of the Board, this
option will terminate on the Final Exercise Date.

(b)
< 3 Years of Service. If the Grantee ceases to provide Service and at such time
has completed less than three full years of Service as a member of the Board,
this option will terminate on the earlier of (1) 5:00 p.m. ET on the date that
is exactly 3 months after the Grantee ceases to provide Service and (2) the
Final Exercise Date.

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6.
Transfer Restrictions.

This option may not be sold, assigned, transferred, pledged or otherwise
encumbered by the Grantee, either voluntarily or by operation of law, except by
will or the laws of descent and distribution, and during the lifetime of the
Grantee this option shall be exercisable only by the Grantee. Notwithstanding
the foregoing, if the Option Type listed above is “Non-qualified Stock Option”
or “NQ,” then the vested portion of this option may be transferred upon notice
to the Company (a) pursuant to a domestic relations order in settlement of
marital property rights or (b) for estate planning purposes to a trust that is
beneficially owned entirely by the Grantee and his or her Family Members.

7.
Disqualifying Dispositions of Incentive Stock Option Shares.

If the Option Type listed above is “Incentive Stock Option” or “ISO,” the
Grantee understands that in order to obtain the benefits of an incentive stock
option under Section 422 of the Code, among other conditions, no sale or other
disposition may be made of any Shares acquired upon exercise of this option
within 1 year after such Shares were acquired pursuant to such exercise, nor
within 2 years after the Grant Date. If the Grantee intends to dispose, or does
dispose (whether by sale, exchange, gift, transfer or otherwise, including
“sell-to-cover” dispositions), of any such Shares within said periods, the
Grantee must notify the Company about such disposition in writing within 10 days
after such disposition, and provide any other information regarding such
disposition that the Company may require.

8.
Grant Limitations.

The Plan is established voluntarily by the Company and it is discretionary in
nature. Participation in the Plan is voluntary. This grant and any other awards
under the Plan are voluntary and occasional and do not create any contractual or
other right to receive future awards or benefits in lieu of any awards, even if
similar awards have been granted repeatedly in the past. This grant and the
underlying Shares, and any income derived from them, are not paid in lieu of and
are not intended to replace any pension rights or compensation and are not part
of normal or expected compensation or salary for any purposes, including
calculating any termination, severance, resignation, redundancy, dismissal, end
of service payments, bonuses, long-service awards, life or accidental insurance
benefits, pension or retirement or welfare benefits or similar payments.

9.
Governing Law and Venue.

This grant and agreement shall be governed by, and construed and interpreted in
accordance with, the laws of the State of Delaware, United States of America,
without regard to its conflict of law provisions. The Grantee agrees to the
exclusive jurisdiction of the United States District Court for the District of
Delaware or the Delaware Superior Court, New Castle County for any dispute or
proceeding relating to this grant or agreement.

IN WITNESS WHEREOF, the Company has executed this agreement through its duly
authorized officer.

NxStage Medical, Inc.

By: _____________________
Jeffrey H. Burbank
Chief Executive Officer

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Grantee’s Acceptance

The undersigned hereby accepts the terms of this agreement and acknowledges
receipt of a copy of the Company’s 2014 Omnibus Incentive Plan and related
prospectus.

Grantee: /s/ <first_name> <middle_name> <last_name>
Address:

<address_1>
<address_2>
<city>, <state>
<zip>
<country>

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Schedule A to Stock Option Agreement

Subject to the terms of this Stock Option Agreement and the Plan, this option
will become exercisable (“vest”) for the Shares and on the dates indicated on
this Schedule A, provided that the Grantee continues to provide Service to the
Company or an Affiliate on such dates and has provided Service at all times
since the Grant Date:

<vesting_schedule>

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Schedule B to Stock Option Agreement

Terms and Conditions
 
This Schedule B includes additional terms and conditions that govern this grant
under the Plan if the Grantee works in one of the countries listed below. If the
Grantee is a citizen or resident of a country other than the one in which the
Grantee is currently working, is considered a resident of another country for
local law purposes or if the Grantee transfers employment or residency between
countries after the Grant Date, the Company will, in its discretion, determine
the extent to which the terms and conditions herein will be applicable to the
Grantee.

ALL NON-U.S. COUNTRIES
 
Data Privacy

The Grantee hereby explicitly and unambiguously consents to the collection, use
and transfer, in electronic or other form, of the Grantee’s personal data as
described in this agreement and any other grant materials by and among, as
applicable, the Grantee’s employer, the Company and its Affiliates for the
exclusive purpose of implementing, administering and managing the Grantee’s
participation in the Plan.
The Grantee understands that the Grantee’s employer, the Company and any
Affiliate may hold certain personal information about the Grantee, including but
not limited to his or her name, home address, telephone number, date of birth,
social security number or other identification number, salary, nationality, job
title, any shares of stock or directorships held in the Company and details of
all grants or any other entitlements to shares of stock awarded, cancelled,
vested, unvested, or outstanding in the Grantee’s favor (“Data”), for the
exclusive purpose of implementing, administering or managing the Plan. Certain
Data may also constitute “sensitive personal data” within the meaning of
applicable local law. Such Data includes, but is not limited to, the information
provided above and any changes thereto and other appropriate personal and
financial data about the Grantee. The Grantee hereby provides explicit consent
to the Grantee’s employer, the Company and any Affiliate to process any such
Data.

The Grantee understands that Data will be transferred to Charles Schwab & Co, or
such other stock plan service provider as may be selected by the Company in the
future, which is assisting the Company with the implementation, administration
and management of the Plan. The Grantee understands that the recipients of the
Data may be located in the United States or elsewhere, and that the recipients’
country (e.g., the United States) may have different data privacy laws and
protections than the Grantee’s country. The Grantee understands that if he or
she resides outside the United States, he or she may request a list with the
names and addresses of any potential recipients of the Data by contacting his or
her local human resources representative. The Grantee authorizes the Company,
Charles Schwab & Co and any other possible recipients which may assist the
Company (presently or in the future) with implementing, administering and
managing the Plan to receive, possess, use, retain and transfer the Data, in
electronic or other form, for the sole purpose of implementing, administering
and managing his or her participation in the Plan. The Grantee understands that
Data will be held only as long as is necessary to implement, administer and
manage the Grantee’s participation in the Plan. The Grantee understands if he or
she resides outside the United States, he or she may, at any time, view Data,
request additional information about the storage and processing of Data, require
any necessary amendments to Data or refuse or withdraw the consents herein, in
any case without cost, by contacting in writing his or her local human resources
representative. Further, the Grantee understands that he or she is providing the
consents herein on a purely voluntary basis. If the Grantee does not consent, or
if the Grantee later seeks to revoke his or her consent, his or her employment
status or service and career with the Grantee’s employer will not be adversely
affected; the only adverse consequence of refusing or withdrawing the Grantee’s
consent is that

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the Company would not be able to provide the Grantee with grants or other equity
awards or administer or maintain such awards. Therefore, the Grantee understands
that refusing or withdrawing his or her consent may affect the Grantee’s ability
to participate in the Plan. For more information on the consequences of the
Grantee’s refusal to consent or withdrawal of consent, the Grantee understands
that he or she may contact his or her local human resources representative.

Form of Payment

Due to legal restrictions outside the U.S., the Grantee is not permitted to
surrender Shares that the Grantee already owns to pay any exercise price of this
grant or to satisfy any tax obligations in connection with this grant.

UNITED KINGDOM

Responsibility for Taxes

The following provisions supplement Section 3 of this agreement:

If payment or withholding of income taxes is not made within ninety (90) days of
the end of the tax year in which the income tax liability arises, or such other
period specified in Section 222(1)(c) of the U.K. Income Tax (Earnings and
Pensions) Act 2003 (the “Due Date”), the amount of any uncollected income tax
shall constitute a loan owed by the Grantee to the Grantee’s employer, effective
on the Due Date. The Grantee understands and agrees that the loan will bear
interest at the then-current official rate of Her Majesty’s Revenue and Customs
(“HMRC”), it will be immediately due and repayable by the Grantee, and the
Company or the Grantee’s employer may recover it at any time thereafter by any
of the means referred to in Section 3 of this agreement. The Grantee also
authorizes the Company to delay the issuance of any Shares to the Grantee unless
and until the loan is repaid in full.

Notwithstanding the foregoing, if the Grantee is a director or an executive
officer (as within the meaning of Section 13(k) of the U.S. Securities Exchange
Act of 1934, as amended), the Grantee will not be eligible for such a loan to
cover the uncollected income tax. In the event that the Grantee is a director or
executive officer and the income tax is not collected from or paid by the
Grantee by the Due Date, the Grantee understands that the amount of any
uncollected income tax may constitute a benefit to the Grantee on which
additional income tax and national insurance contributions (“NICs”) may be
payable. The Grantee will be responsible for reporting and paying any income tax
due on this additional benefit directly to HMRC under the self-assessment regime
and for reimbursing the Company or the Grantee’s employer (as appropriate) for
the value of any employee NICs due on this additional benefit, which the Company
or the Grantee’s employer may recover from the Grantee by any of the means
referred to in Section 3 of this agreement.

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