EXHIBIT 99.2
 
                         NOTICE OF GUARANTEED DELIVERY
 
                                      FOR
                           TENDER OF ALL OUTSTANDING
                      9.45% SENIOR DISCOUNT NOTES DUE 2008
                              IN EXCHANGE FOR NEW
                      9.45% SENIOR DISCOUNT NOTES DUE 2008
                                       OF
                         NEXTLINK COMMUNICATIONS, INC.
 
    As set forth in the Prospectus dated June       , 1998 (as the same may be
amended from time to time, the "Prospectus") of NEXTLINK Communications, Inc.
(the "Company") under the caption "The Exchange Offer--Guaranteed Delivery
Procedures," and in the accompanying Letter of Transmittal (the "Letter of
Transmittal") and Instruction 2 thereto, this form or one substantially
equivalent, must be used to tender any of the Company's outstanding 9.45% Senior
Notes due 2008 (the "Old Notes") pursuant to the Exchange Offer, if (i)
certificates representing the Old Notes to be tendered for exchange are not lost
but are not immediately available, (ii) time will not permit a Holder's Letter
of Transmittal, certificates representing the Old Notes to be tendered and all
other required documents to reach United States Trust Company (the "Exchange
Agent") prior to the Expiration Date with respect to the Exchange Offer, or
(iii) the procedures for book-entry transfer cannot be completed prior to the
Expiration Date. This form may be delivered by an Eligible Institution by mail
or hand delivery or transmitted, via manually signed facsimile, to the Exchange
Agent as set forth below.
 
    Terms not otherwise defined herein shall have their respective meanings as
set forth in the Prospectus.
 
THE EXCHANGE OFFER WILL EXPIRE AT 5:00 P.M., NEW YORK CITY TIME, ON     , 1998,
             UNLESS EXTENDED OR TERMINATED (THE "EXPIRATION DATE").
 
                 THE EXCHANGE AGENT FOR THE EXCHANGE OFFER IS:
                    UNITED STATES TRUST COMPANY OF NEW YORK
 


       BY FACSIMILE:                     BY MAIL:                BY HAND BEFORE 4:30 P.M.:
 
                                                         
      (212) 780-0592           United States Trust Company      United States Trust Company
Attention: Customer Service            of New York                      of New York
 Confirm by Telephone to:      P.O. Box 843 Cooper Station             111 Broadway
      (800) 548-6565             New York, New York 10276        New York, New York 10006
                                Attention: Corporate Trust        Attention: Lower Level
                                         Services                 Corporate Trust Window
 
        BY OVERNIGHT COURIER AND BY HAND AFTER 4:30 P.M. ON THE EXPIRATION DATE ONLY
                          United States Trust Company of New York
                                  770 Broadway, 13th Floor
                                  New York, New York 10003

 

    DELIVERY OF THIS NOTICE OF GUARANTEED DELIVERY TO AN ADDRESS OTHER THAN AS
SET FORTH ABOVE OR TRANSMISSION OF INSTRUCTIONS VIA FACSIMILE TRANSMISSION TO A
NUMBER OTHER THAN AS SET FORTH ABOVE WILL NOT CONSTITUTE A VALID DELIVERY.
 
                                       2

LADIES AND GENTLEMEN:
 
The undersigned hereby tender(s) to the Company, upon the terms and subject to
the conditions set forth in the Prospectus and the Letter of Transmittal,
receipt of which is hereby acknowledged, the principal amount of Old Notes set
forth below pursuant to the guaranteed delivery procedures set forth in the
Prospectus under the caption "The Exchange Offer--Guaranteed Delivery
Procedures."
 
    The undersigned hereby represents and warrants that the undersigned has full
power and authority to tender the Old Notes. The undersigned will, upon request,
execute and deliver any additional documents deemed by the Exchange Agent or the
Company to be necessary or desirable for the perfection of the undersigned's
tender.
 
    Tenders may be withdrawn in accordance with the procedures set forth in the
Prospectus. The undersigned authorizes the Exchange Agent to deliver this Notice
of Guaranteed Delivery to the Company and the Trustee as evidence of the
undersigned's tender of Old Notes.
 
    All authority herein conferred or agreed to be conferred by this Notice of
Guaranteed Delivery shall survive the death or incapacity of the undersigned and
every obligation of the undersigned under this Notice of Guaranteed Delivery
shall be binding upon the heirs, personal representatives, executors,
administrators, successors, assigns, trustees in bankruptcy and other legal
representatives of the undersigned.
 
                                       3

 
                           PLEASE SIGN AND COMPLETE
 
Signatures of Registered Holder(s) or Date:
Authorized Signatory:                 Address:
 
Name(s) of Registered Holder(s):      Area Code and Telephone No.:
 
Principal Amount of Notes Tendered:   If Notes will be delivered by book-entry
                                      transfer, complete the following:
Certificate No.(s) of Notes (if       Depository Account No.
  available):
 
                                       4

 
This Notice of Guaranteed Delivery must be signed by the Holder(s) exactly as
  their names appear on certificates for Old Notes or on a security position
listing as the owner of Old Notes, or by person(s) authorized to become
Holder(s) by endorsements and documents transmitted with this Notice of
Guaranteed Delivery. If signature is by a trustee, executor, administrator,
guardian, attorney-in-fact, officer or other person acting in a fiduciary or
representative capacity, such person must set forth his or her full title below
under "Capacity" and submit evidence satisfactory to the Company of such
person's authority to so act.
 
                      Please print name(s) and address(es)
Name(s):
Capacity:
Address(es):
 
DO NOT SEND OLD NOTES WITH THIS FORM. OLD NOTES SHOULD BE SENT TO THE EXCHANGE
AGENT, TOGETHER WITH A PROPERLY COMPLETED AND VALIDLY EXECUTED LETTER OF
TRANSMITTAL AND ANY OTHER RELATED DOCUMENTS.
                                   GUARANTEE
                    (NOT TO BE USED FOR SIGNATURE GUARANTEE)
 
The undersigned, a member firm of a registered national securities exchange or
of the National Association of Securities Dealers, Inc. or a commercial bank or
trust company having an office or correspondent in the United States, hereby
guarantees that, within three Nasdaq National Market trading days from the date
of this Notice of Guaranteed Delivery, a properly completed and duly executed
Letter of Transmittal (or a manually signed facsimile thereof), together with
certificates representing the Old Notes tendered hereby in proper form for
transfer (or confirmation of the book-entry transfer of such Old Notes into the
Exchange Agent's account at a Book-Entry Transfer Facility, pursuant to the
procedure for book-entry transfer set forth in the Prospectus under the caption
"The Exchange Offer--Book-Entry Transfer"), and any other required documents
will be deposited by the undersigned with the Exchange Agent at its address set
forth above.
 

                                                                               
Name of Firm:
Address:                                                                          Authorized Signature
                                                                                  Name:
Area Code and                                                                     Title:
Telephone No.:                                                                    Date:

 
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