June 7, 2019

Chad Robins
Chief Executive Officer
Adaptive Biotechnologies Corporation
1551 Eastlake Avenue East
Suite 200
Seattle, WA 98102

       Re: Adaptive Biotechnologies Corporation
           Registration Statement on Form S-1
           Filed May 30, 2019
           File No. 333-231838

Dear Mr. Robins:

       We have reviewed your registration statement and have the following
comments. In
some of our comments, we may ask you to provide us with information so we may
better
understand your disclosure.

       Please respond to this letter by amending your registration statement
and providing the
requested information. If you do not believe our comments apply to your facts
and
circumstances or do not believe an amendment is appropriate, please tell us why
in your
response.

       After reviewing any amendment to your registration statement and the
information you
provide in response to these comments, we may have additional comments.

Registration Statement on Form S-1

Share-Based Compensation, page 103

1.     We have reviewed your response to prior comment twelve from our letter
dated April 25,
       2019. Please provide us with the following additional information:
         In your response you attribute, in part, the difference between the
fair value of the
          company's common stock in June 2019 and the anticipated price range
to IPO scenario
          probability. We note the IPO scenario probability used in your June
2019 valuation
          was 80%. Tell us the fair value of the company's common stock if a
100% IPO
          probability was used.
         You indicate that the valuations obtained by management utilize a
quantitative
          methodology to determine the estimated fair value of the company's
common stock,
 Chad Robins
FirstName LastNameChadCorporation
Adaptive Biotechnologies Robins
Comapany NameAdaptive Biotechnologies Corporation
June 7, 2019
June 7, 2019 Page 2
Page 2
FirstName LastName
             which may differ from a more qualitative and subjective
methodology used by some
             public market investors to determine the price they are willing to
pay in an IPO. Tell
             us the specific qualitative factors you believe support the
difference between the fair
             value of the company's common stock in June 2019 and the
anticipated price range.
             Provide us with your calculation of the June 2019 common stock
fair value per share,
             including your starting point and any adjustments necessary when
determining fair
             value, for example, to recognize a lack of marketability of the
company's common
             stock.
             Tell us the vesting period of the options granted in 2019.
Consolidated Financial Statements
Notes to Consolidated Financial Statements
Microsoft Collaboration Agreement, page F-32

2.       We have reviewed your response to prior comment five. Please expand
your accounting
         analysis to more clearly articulate how you determined unit of
account, measurement, and
         recognition. See, e.g. ASC 808-10-15-5B and 5C. Please include in your
analysis:
           the convertible preferred stock concurrently issued and the $45
million received;
           identification and analysis of the authoritative literature you used
to determine unit of
            account, measurement and recognition, including the allocation of
arrangement
            consideration to those units, indicating whether the cited
literature applies directly or
            is used by analogy; and
           to the extent you are relying on an analogy, your supporting
analysis that the units are
            outside the scope of other Topics, such as ASC 610.
3.       Please provide an analysis to support your assertion that Microsoft is
not a customer as
         that term is defined in ASC 606 for one or more aspects of the
arrangement. For example,
         we note that you granted Microsoft a license to use TCR-antigen map
data and
         computational models, which appear to be defined as mathematical
representations of
         various mappings or predictions of interest related to TCR-antigen
associations, and that
         your ordinary activities include providing products and services based
on your proprietary
         technologies related to the adaptive immune system.
        We remind you that the company and its management are responsible for
the accuracy
and adequacy of their disclosures, notwithstanding any review, comments, action
or absence of
action by the staff.

       Refer to Rules 460 and 461 regarding requests for acceleration. Please
allow adequate
time for us to review any amendment prior to the requested effective date of
the registration
statement.
 Chad Robins
Adaptive Biotechnologies Corporation
June 7, 2019
Page 3

       You may contact Andi Carpenter at 202-551-3645 or Sharon Blume at
202-551-3474 if
you have questions regarding comments on the financial statements and related
matters. Please
contact Julie Griffith at 202-551-3267 or Justin Dobbie at 202-551-3649 with
any other
questions.



FirstName LastNameChad Robins                             Sincerely,
Comapany NameAdaptive Biotechnologies Corporation
                                                          Division of
Corporation Finance
June 7, 2019 Page 3                                       Office of Healthcare
& Insurance
FirstName LastName