ICG SERVICES INC.

                          10% Senior Discount Note Due 2008

                                                            CUSIP
                                                                 ----------

          No.                                                $              
              ----                                            -------------

                    The following information is supplied for purposes of
          Sections 1273 and 1275 of the Internal Revenue Code:
                  
         Issue Date:  February 12, 1998          Original issue discount under
                                                 Section 1273 of the Internal
         Yield to maturity for period from       Revenue Code (for each $1,000
         Issue Date to February 15, 2008:        principal amount at maturity):
         10.00%, compounded semiannually         $886.59
         on February 15 and August 15
         commencing February 12, 1998            Issue Price (for each $1,000
         (computed without giving effect         principal amount at maturity):
         to the additional payments of           $613.41
         interest in the event the issuer
         fails to commence the exchange
         offer and fails to cause the
         shelf registration statement
         to be declared effective, each
         as referred to on the reverse hereof)


                    ICG SERVICES, INC., a Delaware corporation (the
          "Company", which term includes any successor under the Indenture
          hereinafter referred to), for value received, promises to pay to  
                                   , or its registered assigns, the 
          -------------------------
          principal sum of                                  Dollars 
                           --------------------------------
          ($                   ) on February 15, 2008.
            -------------------

                    Interest Payment Dates:  February 15 and August 15,
          commencing August 15, 2003.

                    Regular Record Dates:  February 1 and August 1.

                    Reference is hereby made to the further provisions of
          this Note set forth on the reverse hereof, which further
          provisions shall for all purposes have the same effect as if set
          forth at this place.

     

                    IN WITNESS WHEREOF, the Company has caused this Note to
          be signed manually or by facsimile by its duly authorized
          officers.


          Date:  February 12, 1998         ICG SERVICES, INC.


                                           By:
                                              ----------------------------
                                              Name:
                                              Title:


                                           By:
                                              ----------------------------
                                              Name:
                                              Title:


                  (Form of Trustee's Certificate of Authentication)

          This is one of the 10% Senior Discount Notes due 2008 described
          in the within-mentioned Indenture.


                                        NORWEST BANK COLORADO,
                                        NATIONAL ASSOCIATION, as Trustee


                                        By:
                                           -----------------------------
                                                Authorized Signatory




                                      -2-
     


                                [REVERSE SIDE OF NOTE]

                                  ICG SERVICES, INC.

                          10% Senior Discount Note due 2008



          1.   Principal and Interest.
               ----------------------

                    The Company will pay the principal of this 10% Senior
          Discount Note due 2008 (the "Note") on February 15, 2008.

                    The Company promises to pay interest on the principal
          amount of this Note on each Interest Payment Date, as set forth
          below, at the rate per annum shown above.

                    Interest will be payable semiannually (to the holders
          of record of the Notes at the close of business on the February 1
          or August 1 immediately preceding the Interest Payment Date) on
          each Interest Payment Date, commencing August 15, 2003; provided
          that no interest shall accrue on the principal amount of this
          Note prior to February 15, 2003 and no interest shall be paid on
          this Note prior to August 15, 2003.

                    From and after February 15, 2003, interest on the Notes
          will accrue from the most recent date to which interest has been
          paid or, if no interest has been paid, from February 15, 2003;
          provided that, if there is no existing default in the payment of
          interest and this Note is authenticated between a Regular Record
          Date referred to on the face hereof and the next succeeding
          Interest Payment Date, interest shall accrue from such Interest
          Payment Date.  Interest will be computed on the basis of a
          360-day year of twelve 30-day months.

                    The Company shall pay interest on overdue principal and
          premium, if any, and interest on overdue installments of
          interest, to the extent lawful, at a rate per annum that is 2% in
          excess of the rate otherwise payable.

          2.   Method of Payment.
               -----------------

                    The Company will pay principal as provided above and
          interest (except defaulted interest) on the principal amount of
          the Notes as provided above on each February 15 and August 15 to
          the Persons who are Holders (as reflected in the Note Register at
          the close of business on such February 1 and August 1 immediately
          preceding the Interest Payment Date), in each case, even if the
          Note is cancelled on registration of transfer or registration of
          exchange after such record date; provided that, with respect to
          the payment of principal, the Company will not make payment to
          the Holder unless this Note is surrendered to a Paying Agent.


                                      -3-
     

                    The Company will pay principal, premium, if any, and as
          provided above, interest in money of the United States that at
          the time of payment is legal tender for payment of public and
          private debts.  However, the Company may pay principal, premium,
          if any, and interest by its check payable in such money.  It may
          mail an interest check to a Holder's registered address (as
          reflected in the Note Register).  If a payment date is a date
          other than a Business Day at a place of payment, payment may be
          made at that place on the next succeeding day that is a Business
          Day and no interest shall accrue for the intervening period.

          3.   Paying Agent and Registrar.
               --------------------------

                    Initially, the Trustee will act as authenticating
          agent, Paying Agent and Registrar.  The Company may change any
          authenticating agent, Paying Agent or Registrar without notice. 
          The Company, any Subsidiary or any Affiliate of any of them may
          act as Paying Agent, Registrar or co-Registrar.

          4.   Indenture; Issuance of Additional Notes.
               ---------------------------------------

                    The Company issued the Notes under an Indenture dated
          as of February 12, 1998 (the "Indenture"), between the Company
          and Norwest Bank Colorado, N.A., as trustee (the "Trustee"). 
          Capitalized terms herein are used as defined in the Indenture
          unless otherwise indicated.  The terms of the Notes include those
          stated in the Indenture and those made part of the Indenture by
          reference to the Trust Indenture Act.  The Notes are subject to
          all such terms, and Holders are referred to the Indenture and the
          Trust Indenture Act for a statement of all such terms.  To the
          extent permitted by applicable law, in the event of any
          inconsistency between the terms of this Note and the terms of the
          Indenture, the terms of the Indenture shall control.

                    The Notes are general unsecured obligations of the
          Company.  The Company may, subject to Article Four of the
          Indenture, issue additional Notes under the Indenture.

          5.   Redemption.
               ----------

                    The Notes will be redeemable, at the Company's option,
          in whole or in part, at any time or from time to time, on or
          after February 15, 2003 and prior to maturity, upon not less than
          30 nor more than 60 days' prior notice mailed by first class mail
          to each Holder's last address as it appears in the Note Register,
          at the following Redemption Prices (expressed in percentages of
          their principal amount at maturity), plus accrued and unpaid
          interest, if any, to the Redemption Date (subject to the right of
          Holders of record on the relevant Regular Record Date that is on
          or prior to the Redemption Date to receive interest due on an
          Interest Payment Date), if redeemed during the 12-month period
          commencing February 15, of the years set forth below:


                                      -4-
     


                         YEAR                        REDEMPTION PRICE
                         ----                        ----------------
                         2003 . . . . . . . . . .        105.0000%
                         2004 . . . . . . . . . .        103.3333
                         2005 . . . . . . . . . .        101.6667
                         2006 and thereafter  . .        100.0000

                    In addition, at any time or from time to time, on or
          prior to February 15, 2001, the Company may, at its option,
          redeem Notes having an aggregate principal amount at maturity of
          up to 35% of the aggregate principal amount at maturity of the
          Notes with the proceeds of one or more public or private Equity
          Offerings, at a Redemption Price equal to   110.0% of the
          Accreted Value thereof on the Redemption Date; provided that at
          least 65% of the aggregate principal amount of Notes initially
          issued remains outstanding after each such redemption.

          6.   Notice of Redemption.
               --------------------

                    Notice of any optional redemption will be mailed at
          least 30 days but not more than 60 days before the Redemption
          Date to each Holder of Notes to be redeemed at his last address
          as it appears in the Note Register.  Notes in original
          denominations larger than $1,000 of principal amount at maturity
          may be redeemed in part.  On and after the Redemption Date,
          interest ceases to accrue on Notes or portions of Notes called
          for redemption, unless the Company defaults in the payment of the
          Redemption Price.

          7.   Repurchase upon Change in Control.
               ---------------------------------

                    Upon the occurrence of any Change of Control, each
          Holder shall have the right to require the repurchase of its
          Notes by the Company in cash pursuant to the offer described in
          the Indenture at a purchase price equal to 101% of the Accreted
          Value thereof plus accrued and unpaid interest, if any, to the
          date of purchase (the "Change of Control Payment").

                    A notice of such Change of Control will be mailed
          within 30 days after any Change of Control occurs to each Holder
          at his last address as it appears in the Note Register.  Notes in
          original denominations larger than $1,000 of principal amount at
          maturity may be sold to the Company in part.  On and after the
          date of the Change of Control Payment, interest ceases to accrue
          on Notes or portions of Notes surrendered for purchase by the
          Company, unless the Company defaults in the payment of the Change
          of Control Payment.

          8.   Denominations; Transfer; Exchange.
               ---------------------------------

                    The Notes are in registered form without coupons in
          denominations of $1,000 of principal amount at maturity and
          multiples of $1,000 in excess thereof.  A Holder may register the
          transfer or exchange of Notes in accordance with the Indenture.


                                      -5-
     


          The Registrar may require a Holder, among other things, to
          furnish appropriate endorsements and transfer documents and to
          pay any taxes and fees required by law or permitted by the
          Indenture.  The Registrar need not register the transfer or
          exchange of any Notes selected for redemption.  Also, it need not
          register the transfer or exchange of any Notes for a period of 15
          days before a selection of Notes to be redeemed is made.

          9.   Persons Deemed Owners.
               ---------------------

                    A Holder shall be treated as the owner of a Note for
          all purposes.

          10.  Unclaimed Money.
               ---------------

                    If money for the payment of principal, premium, if any,
          or interest remains unclaimed for two years, the Trustee and the
          Paying Agent will pay the money back to the Company at its
          request.  After that, Holders entitled to the money must look to
          the Company for payment, unless an abandoned property law
          designates another Person, and all liability of the Trustee and
          such Paying Agent with respect to such money shall cease.

          11.  Discharge Prior to Redemption or Maturity.
               -----------------------------------------

                    If the Company deposits with the Trustee money and/or
          U.S. Government Obligations sufficient to pay the then
          outstanding principal of, premium, if any, and accrued interest
          on the Notes (a) to redemption or maturity, the Company will be
          discharged from the Indenture and the Notes, except in certain
          circumstances for certain sections thereof, and (b) to Stated
          Maturity, the Company will be discharged from certain covenants
          set forth in the Indenture.

          12.  Amendment; Supplement; Waiver.
               -----------------------------

                    Subject to certain exceptions, the Indenture or the
          Notes may be amended or supplemented with the consent of the
          Holders of at least a majority in principal amount at maturity of
          the Notes then outstanding, and any existing default or
          compliance with any provision may be waived with the consent of
          the Holders of at least a majority in principal amount at
          maturity of the Notes then outstanding.  Without notice to or the
          consent of any Holder, the parties thereto may amend or
          supplement the Indenture or the Notes to, among other things,
          cure any ambiguity, defect or inconsistency and make any change
          that does not materially and adversely affect the rights of any
          Holder.

          13.  Restrictive Covenants.
               ---------------------

                    The Indenture imposes certain limitations on the
          ability of the Company and its Restricted Subsidiaries, among
          other things, to Incur Indebtedness, make Restricted Payments,
          use the proceeds from Asset Sales, engage in transactions with


                                      -6-
     


          Affiliates or, with respect to the Company, merge, consolidate or
          transfer substantially all of its assets.  Within 90 days after
          the end of the last fiscal quarter of each year, the Company must
          report to the Trustee on compliance with the terms of the
          Indenture.

          14.  Successor Persons.
               -----------------

                    When a successor Person or other entity assumes all the
          obligations of its predecessor under the Notes and the Indenture,
          the predecessor Person will be released from those obligations.

          15.  Defaults and Remedies.
               ---------------------

                    The following events constitute "Events of Default"
          under the Indenture:  (a) default in the payment of principal of
          (or premium, if any, on) any Note when the same becomes due and
          payable at maturity, upon acceleration, redemption or otherwise;
          (b) default in the payment of interest on any Note when the same
          becomes due and payable, and such default continues for a period
          of 30 days; (c) the Company defaults in the performance of or
          breaches any other covenant or agreement of the Company in the
          Indenture or under the Notes (other than a default specified in
          clause (a) or (b) above) and such default or breach continues for
          a period of 30 consecutive days after written notice by the
          Trustee or the Holders of 25% or more in aggregate principal
          amount of the Notes; (d) the Company fails to make or consummate
          an Offer to Purchase in accordance with Section 4.11 of the
          Indenture; (e) the Company fails to make or consummate an Offer
          to Purchase in accordance with Section 4.12 of the Indenture; (f)
          there occurs with respect to any issue or issues of Indebtedness
          of the Company or any Significant Subsidiary having an
          outstanding principal amount of $10 million or more in the
          aggregate for all such issues of all such Persons, whether such
          Indebtedness now exists or shall hereafter be created, (I) an
          event of default that has caused the holder thereof to declare
          such Indebtedness to be due and payable prior to its Stated
          Maturity and such Indebtedness has not been discharged in full or
          such acceleration has not been rescinded or annulled within 30
          days of such acceleration and/or (II) the failure to make a
          principal payment at the final (but not any interim) fixed
          maturity and such defaulted payment shall not have been made,
          waived or extended within 30 days of such payment default; (g)
          any final judgment or order (not covered by insurance) for the
          payment of money in excess of $10 million in the aggregate
          (treating any deductibles, self-insurance or retention as not so
          covered) shall be rendered against the Company or any Significant
          Subsidiary and shall not be paid or discharged, and there shall
          be any period of 30 consecutive days following entry of the final
          judgment or order that causes the aggregate amount for all such
          final judgments or orders outstanding and not paid or discharged
          against the Company or any of its Significant Subsidiaries to
          exceed $10 million during which a stay of enforcement of such
          final judgment or order, by reason of a pending appeal or
          otherwise, shall not be in effect; (h) a court having
          jurisdiction in the premises enters a decree or order for (A)
          relief in respect of the Company or any Significant Subsidiary in
          an involuntary case under any applicable bankruptcy, insolvency
          or other similar law now or hereafter in effect, (B) appointment


                                      -7-
     

          of a receiver, liquidator, assignee, custodian, trustee,
          sequestrator or similar official of the Company or any
          Significant Subsidiary or for all or substantially all of the
          property and assets of the Company or any Significant Subsidiary
          or (C) the winding up or liquidation of the affairs of the
          Company or any Significant Subsidiary and, in each case, such
          decree or order shall remain unstayed and in effect for a period
          of 30 consecutive days; or (i) the Company or any Significant
          Subsidiary (A) commences a voluntary case under any applicable
          bankruptcy, insolvency or other similar law now or hereafter in
          effect, or consents to the entry of an order for relief in an
          involuntary case under any such law, (B) consents to the
          appointment of or taking possession by a receiver, liquidator,
          assignee, custodian, trustee, sequestrator or similar official of
          the Company or any Significant Subsidiary or for all or
          substantially all of the property and assets of the Company or
          any Significant Subsidiary or (C) effects any general assignment
          for the benefit of creditors.

                    If an Event of Default (other than an Event of Default
          specified in clause (h) or (i) above that occurs with respect to
          the Company) occurs and is continuing under the Indenture, the
          Trustee or the Holders of at least 25% in aggregate principal
          amount at maturity of the Notes, then outstanding, by written
          notice to the Company (and to the Trustee if such notice is given
          by the Holders), may, and the Trustee at the request of such
          Holders shall, declare the Accreted Value of, premium, if any,
          and accrued interest, if any, on the Notes to be immediately due
          and payable.

                    If an Event of Default occurs and is continuing, the
          Trustee or the Holders of at least 25% in aggregate principal
          amount at maturity of the Notes then outstanding may declare all
          the Notes to be due and payable.  If a bankruptcy or insolvency
          default with respect to the Company or any Restricted Subsidiary
          occurs and is continuing, the Notes automatically become due and
          payable.  Holders may not enforce the Indenture or the Notes
          except as provided in the Indenture.  The Trustee may require
          indemnity satisfactory to it before it enforces the Indenture or
          the Notes.  Subject to certain limitations, Holders of at least a
          majority in principal amount at maturity of the Notes then
          outstanding may direct the Trustee in its exercise of any trust
          or power.

          16.  Trustee Dealings with Company.
               -----------------------------

                    The Trustee under the Indenture, in its individual or
          any other capacity, may make loans to, accept deposits from and
          perform services for the Company or its Affiliates and may
          otherwise deal with the Company or its Affiliates as if it were
          not the Trustee.

          17.  No Recourse Against Others.
               --------------------------

                    No incorporator or any past, present or future partner,
          stockholder, other equity holder, officer, director, employee or
          controlling person as such, of the Company or of any successor
          Person shall have any liability for any obligations of the
          Company under the Notes or the Indenture or for any claim based
          on, in respect of or by reason of, such obligations or their


                                      -8-
     


          creation.  Each Holder by accepting a Note waives and releases
          all such liability.  The waiver and release are part of the
          consideration for the issuance of the Notes.

          18.  Authentication.
               --------------

                    This Note shall not be valid until the Trustee or
          authenticating agent signs the certificate of authentication on
          the other side of this Note.

          19.  Abbreviations.
               -------------

                    Customary abbreviations may be used in the name of a
          Holder or an assignee, such as:  TEN COM (= tenants in common),
          TEN ENT (= tenants by the entireties), JT TEN (= joint tenants
          with right of survivorship and not as tenants in common), CUST
          (= Custodian) and U/G/M/A (= Uniform Gifts to Minors Act).

               THIS NOTE SHALL BE GOVERNED BY THE LAWS OF THE STATE OF NEW
          YORK.

                    The Company will furnish to any Holder upon written
          request and without charge a copy of the Indenture.  Requests may
          be made to ICG Services, Inc., 161 Inverness Drive West,
          Englewood, Colorado 80112, Attention:  Chief Financial Officer.



                                      -9-
     


                                   TRANSFER NOTICE

                    FOR VALUE RECEIVED the undersigned registered holder
          hereby sell(s), assign(s) and transfer(s) unto

          Insert Taxpayer Identification No.
          ---------------------------------

          -----------------------------------------------------------------
          Please print or typewrite name and address including zip code of
          assignee

          -----------------------------------------------------------------
          the within Note and all rights thereunder, hereby irrevocably
          constituting and appointing                              attorney
                                      ----------------------------
          to transfer said Note on the books of the Company with full power
          of substitution in the premises.


          Date:
               ---------------     ----------------------------------------
                                   NOTICE:  The signature to this
                                   assignment must correspond with the name
                                   as written upon the face of the within-
                                   mentioned instrument in every
                                   particular, without alteration or any
                                   change whatsoever.




                          OPTION OF HOLDER TO ELECT PURCHASE


                    If you wish to have this Note purchased by the Company
          pursuant to Section 4.11 or Section 4.12 of the Indenture, check
          the Box:  [ ]

                    If you wish to have a portion of this Note purchased by
          the Company pursuant to Section 4.11 or Section 4.12 of the
          Indenture, state the amount (in principal amount at maturity):  
          $                    .
           -------------------

          Date:
               -----------------

          Your Signature:
                         --------------------------------------------------
                         (Sign exactly as your name appears on the other
                         side of this Note)

          Signature Guarantee:
                              -----------------------------



                                      -10-