Mail Stop 3561

      							December 22, 2005

Via U.S. Mail and Fax
Mr. William Garrahan
Acting Chief Financial Officer
XO Communications, Inc.
11111 Sunset Hills Road
Reston, VA  20190

	RE:	XO Communications, Inc.
      Form 10-K for Fiscal Year Ended December 31, 2004
		Filed March 18, 2005
		Forms 10-Q for Fiscal Quarter Ended September 30, 2005
		File No. 0-30900

Dear Mr. Garrahan:

      We have reviewed your filings and have the following
comments.
We have limited our review to only your financial statements and
related disclosures and do not intend to expand our review to
other
portions of your documents.  Please address the following comment
in
future filings.  If you disagree, we will consider your
explanation
as to why our comment is inapplicable or a future revision is
unnecessary.  Please be as detailed as necessary in your
explanation.
In our comment, we may ask you to provide us with information so
we
may better understand your disclosure.  After reviewing this
information, we may or may not raise additional comments.

	Please understand that the purpose of our review process is
to
assist you in your compliance with the applicable disclosure
requirements and to enhance the overall disclosure in your filing.
We look forward to working with you in these respects.  We welcome
any questions you may have about our comments or any other aspect
of
our review.  Feel free to call us at the telephone numbers listed
at
the end of this letter.

      Form 10-K for the year ended December 31, 2004

      Note 10 - Convertible preferred stock, page F-19

1. Tell us how you concluded that the conversion feature in your
convertible preferred stock does not meet the definition of an
embedded derivative under SFAS 133 and EITF 00-19.


      Please respond to this comment within 10 business days or
tell
us when you will provide us with a response.  Please furnish a
letter
that keys your responses to our comment and provides any requested
information.  Detailed letters greatly facilitate our review.
Please
file your letter on EDGAR.  Please understand that we may have
additional comments after reviewing your responses to our comment.

	We urge all persons who are responsible for the accuracy and
adequacy of the disclosure in the filing to be certain that the
filing includes all information required under the Securities
Exchange Act of 1934 and that they have provided all information
investors require for an informed investment decision.  Since the
company and its management are in possession of all facts relating
to
a company`s disclosure, they are responsible for the accuracy and
adequacy of the disclosures they have made.

	In connection with responding to our comments, please
provide,
in writing, a statement from the company acknowledging that

* the company is responsible for the adequacy and accuracy of the
disclosure in the filings;

* staff comments or changes to disclosure in response to staff
comments do not foreclose the Commission from taking any action
with
respect to the filings; and

* the company may not assert staff comments as a defense in any
proceeding initiated by the Commission or any person under the
federal securities laws of the United States.

      In addition, please be advised that the Division of
Enforcement
has access to all information you provide to the staff of the
Division of Corporation Finance in our review of your filings or
in
response to our comments on your filings.

      You may contact Gopal Dharia, Staff Accountant, at (202)
551-
3353 or Ivette Leon, Assistant Chief Accountant, at (202) 551-3351
if
you have questions regarding comments on the financial statements
and
related matters.  Please contact me at (202) 551-3810 with any
other
questions.

								Sincerely,


      Larry Spirgel
								Assistant Director
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Mr. William Garrahan
XO Communications, Inc.
January 9, 2006
Page 1



UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

         DIVISION OF
CORPORATION FINANCE