AMENDMENT NO. 1
                                       TO
                           LOAN AND SECURITY AGREEMENT


         AMENDMENT NO. 1 TO LOAN AND SECURITY AGREEMENT  ("AMENDMENT")  dated as
of March 3, 1999, among KMC TELECOM INC., a Delaware  corporation  ("KMC"),  KMC
Telecom II, Inc., a Delaware  corporation  ("KMC II"),  KMC Telecom of Virginia,
Inc., a Virginia public service company ("KMC VIRGINIA"),  KMC Telecom Leasing I
LLC, a Delaware limited  liability company ("LEASING I"), KMC Telecom Leasing II
LLC, a Delaware  limited  liability  company  ("LEASING  II";  KMC,  KMC II, KMC
Virginia,  Leasing I and Leasing II being hereinafter  collectively  referred to
hereinafter as the "BORROWERS" ), the financial  institutions  from time to time
parties thereto (the  "LENDERS"),  FIRST UNION NATIONAL BANK, as  administrative
agent for the Lenders (the "AGENT") and NEWCOURT  COMMERCIAL FINANCE CORPORATION
(f/k/a AT&T COMMERCIAL FINANCE CORPORATION), as collateral agent for the Lenders
(the  "COLLATERAL  AGENT";  the Agent together with the  Collateral  Agent being
referred to as the "AGENTS").

         WHEREAS, the Borrowers,  the Agents and the Lenders are parties to that
certain Loan and Security Agreement (the "LOAN AGREEMENT"; undefined capitalized
terms  used  herein  shall  have  the  meanings  assigned  thereto  in the  Loan
Agreement)  dated as of December  22,  1998,  pursuant to which the Lenders have
agreed  to make  certain  "Loans"  and  other  financial  accommodations  to the
Borrowers; and

         WHEREAS,  the Borrowers  have requested that the Agents and the Lenders
amend the Loan Agreement in the manner set forth herein,  and the Agents and the
Lenders have agreed to such request;

         NOW,  THEREFORE,  in consideration of the premises set forth above, and
for other good and valuable consideration,  the receipt and sufficiency of which
are hereby  acknowledged,  the  Borrowers,  the Agents and the Lenders  agree as
follows:

         1.  AMENDMENT  TO THE LOAN  AGREEMENT.  Effective  as of the date first
above  written and subject to the  execution  of this  Amendment  by the parties
hereto, the Loan Agreement shall be and hereby is amended as follows:

         1.1 SECTIONS  2.03(A) and (B) of the Loan  Agreement are hereby deleted
in their entirety and the following language is substituted therefor:

         SECTION 2.03. PROCEDURE FOR LOAN REQUEST AND BORROWING COMMITMENT.  (a)
         A Borrower requesting a Loan shall deliver to each of the Agent and the
         Collateral  Agent a Notice of  Borrowing  substantially  in the form of
         EXHIBIT H-1 attached  hereto on or before 11:00 a.m. (New York time) at
       






         least  five (5)  Business  Days prior to the date on which such Loan is
         requested  to be made if such Loan is  requested to be a LIBOR Loan and
         at least two (2) Business  Days prior to the date on which such Loan is
         requested  to be made if such Loan is requested to be a Base Rate Loan,
         which notice, once given, shall be irrevocable; provided, however, that
         only the Collateral  Agent shall receive the  attachments to the Notice
         of  Borrowing,  as  outlined  below.  The  Revolving  Loans made on the
         Initial  Funding  Date shall be Base Rate Loans and  thereafter  may be
         continued  as Base Rate  Loans or  converted  into  LIBOR  Loans in the
         manner provided in SECTION 2.06 and subject to the other conditions and
         limitations  therein set forth and set forth in this ARTICLE II. In the
         case of a Loan  the  proceeds  of  which  will be used to  purchase  or
         reimburse any Borrower for Telecommunications  Equipment (including any
         Telecommunications  Equipment being  purchased or reimbursed  under the
         Lucent Purchase  Agreement),  the Notice of Borrowing  delivered to the
         Collateral Agent will include a schedule supporting one hundred percent
         (100%) of  Telecommunications  Equipment  requested to be funded.  Such
         schedule  will detail all  invoices for  equipment,  third party labor,
         permits,  other third party costs and all capitalized internal costs of
         the  Borrowers  with  respect  to  such  Telecommunications   Equipment
         permitted  under GAAP.  All  invoices  over $25,000 will be attached to
         such schedule  delivered to the Collateral  Agent who shall review such
         invoices  and  verify  that,  when  combined  with the above  described
         capitalized internal costs, such invoices will support at least seventy
         percent  (70%) of the total  requested  funding.  In  addition,  if the
         Telecommunications Equipment is being purchased or reimbursed under the
         Lucent Purchase Agreement,  a certificate of delivery and acceptance in
         the form of  EXHIBIT R shall be  attached  to the  Notice of  Borrowing
         delivered to the Collateral  Agent.  In the case of a Loan the proceeds
         of which will be used to pay or reimburse any Borrower for  transaction
         costs,  the Notice of Borrowing  delivered to the Collateral Agent will
         include a copy of the invoice from the provider of the service or other
         appropriate  supporting  documentation.  In the  case  of a  Loan,  the
         proceeds  of which will be used for  working  capital or other  general
         corporate purposes, the Notice of Borrowing delivered to the Collateral
         Agent will  contain a  certification  that the making of such Loan does
         not violate any  provision  of the  Indenture.  The Notice of Borrowing
         shall,  with  respect  to any Loans  requested,  specify  whether  such
         requested  Loans are to be Base Rate Loans or LIBOR Loans,  and if such
         requested  Loans are to be LIBOR Loans,  the requested  Interest Period
         for such Loans.

                  (b) The Agent agrees, promptly upon (i) receipt of a Notice of
         Borrowing  and (ii)  acknowledgment  by the  Collateral  Agent that the
         Borrowers have  delivered and the Collateral  Agent has reviewed to its
         satisfaction  (x) each of the invoices or  certificates  required to be
         provided to the Collateral  Agent pursuant to SECTION 2.03(A) above and
         (y) each of the collateral  documents,  including,  without limitation,
         all third  party  agreements  and the related  consents  to  collateral
         assignments required pursuant to SECTION 5.08 of the Loan Agreement, as
         requested by the  Collateral  Agent,  to notify each  Revolving or Term
         Lender of the date and amount of the Loan proposed  thereunder  and the
         amount of such Lender's Pro Rata Share therein.  So long as no Event of
         Default has  occurred and is  continuing  and upon  fulfillment  of the
         applicable conditions set forth in ARTICLE IV and the

                                        2





         requirements  set forth in SECTION  2.03(A) above and in the applicable
         Notice of Borrowing,  each such Lender severally  agrees,  on or before
         12:00 P.M.  (New York time) on the date of each  proposed  Loan, to pay
         into the Payment  Account,  an amount  equal to such  Lender's Pro Rata
         Share of such Loan in dollars and in same day funds.  After the Agent's
         receipt of such Lender's Loan proceeds,  the Agent shall make available
         such  proceeds  to the  Borrower  requesting  the  Loan  or the  Person
         entitled to payment  thereof at the bank  account(s)  specified  in the
         Notice of Borrowing  on the date  specified in such Notice of Borrowing
         in Dollars in immediately available funds.

                  1.2 EXHIBIT H-1 to the Loan Agreement is hereby deleted in its
         entirety and the Form of Notice of Borrowing attached hereto as EXHIBIT
         H-1 is substituted therefor.

         2. CONDITIONS  PRECEDENT.  This Amendment shall become  effective as of
the date above written,  if, and only if, the Agents have received duly executed
originals of this Amendment from the Borrowers, the Lenders and the Agents.

         3.  REPRESENTATIONS  AND  WARRANTIES  OF THE  BORROWERS.  The Borrowers
hereby represent and warrant as follows:

         (a)  This  Amendment  and  the  Loan  Agreement,   as  amended  hereby,
constitute  legal,  valid  and  binding  obligations  of the  Borrowers  and are
enforceable against the Borrowers in accordance with their terms.

         (b) Upon the  effectiveness  of this  Amendment,  the Borrowers  hereby
reaffirm all representations  and warranties made in the Loan Agreement,  and to
the extent the same are not amended hereby,  agree that all such representations
and warranties shall be deemed to have been remade as of the date of delivery of
this  Amendment,  unless  and to the  extent  that any such  representation  and
warranty  is stated to relate  solely to an  earlier  date,  in which  case such
representation and warranty shall be true and correct as of such earlier date.

         4. REFERENCE TO AND EFFECT ON THE LOAN AGREEMENT.

         (a) Upon the  effectiveness of SECTION 1 hereof,  on and after the date
hereof,  each  reference  in  the  Loan  Agreement  to  "this  Loan  Agreement,"
"hereunder,"  "hereof,"  "herein"  or words of like  import  shall mean and be a
reference to the Loan  Agreement as amended  hereby,  and each  reference to the
Loan Agreement in any other document,  instrument or agreement shall mean and be
a reference to the Loan Agreement as modified hereby.

         (b) The Loan  Agreement,  as amended hereby,  and all other  documents,
instruments and agreements  executed and/or  delivered in connection  therewith,
shall remain in full force and effect, and are hereby ratified and confirmed.


                                        3





         (c) Except as expressly  provided herein,  the execution,  delivery and
effectiveness  of this  Amendment  shall not  operate  as a waiver of any right,
power or remedy of the Agents or the  Lenders,  nor  constitute  a waiver of any
provision  of  the  Loan  Agreement  or any  other  documents,  instruments  and
agreements executed and/or delivered in connection therewith.

         5. GOVERNING LAW. THIS AMENDMENT  SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE OTHER REMAINING TERMS OF THE LOAN AGREEMENT AND THE INTERNAL
LAWS (AS OPPOSED TO CONFLICT OF LAW PROVISIONS) OF THE STATE OF NEW YORK.

         6.  PARAGRAPH  HEADINGS.  The  paragraph  headings  contained  in  this
Amendment  are and shall be  without  substance,  meaning or content of any kind
whatsoever and are not a part of the agreement among the parties hereto.

         7.  COUNTERPARTS.  This  Amendment  may be  executed  in  one  or  more
counterparts,  each of  which  shall be  deemed  an  original,  but all of which
together shall constitute one and the same instrument.



                            [Signature Page Follows]

                                        4





                  IN WITNESS  WHEREOF,  this Amendment has been duly executed as
of the day and year first above written.

THE BORROWERS:                             KMC TELECOM INC.

                                           KMC TELECOM II, INC.

                                           KMC TELECOM OF VIRGINIA, INC.

                                           In each case:


                                           By:/s/ CYNTHIA WORTHMAN
                                              ----------------------------------
                                                Name:  Cynthia Worthman
                                                Title:  Vice President and CFO


                                           KMC TELECOM LEASING I LLC
                                           By:  KMC TELECOM  INC., as its Sole
                                           Member


                                           By:/s/ CYNTHIA WORTHMAN
                                              ----------------------------------
                                                Name:  Cynthia Worthman
                                                Title:  Vice President and CFO


                                           KMC TELECOM LEASING II LLC
                                           By: KMC TELECOM II, INC., as its Sole
                                           Member


                                           By:/s/ CYNTHIA WORTHMAN
                                              ----------------------------------
                                                Name:  Cynthia Worthman
                                                Title:  Vice President and CFO






                                Signature Page-1
                        Amendment No. 1 to Loan Agreement





                                           FIRST UNION NATIONAL BANK, as the
                                           Agent and as a Lender


                                           By:/s/ MARK M. HARDEN
                                              ----------------------------------
                                           Name:   Mark M. Harden
                                           Title:  Senior Vice President


                                           NEWCOURT COMMERCIAL FINANCE
                                           CORPORATION (f/k/a AT&T COMMERCIAL
                                           FINANCE CORPORATION), as the 
                                           Collateral Agent and  as  a Lender


                                           By:/s/ MICHAEL V. MONIHAN
                                              ----------------------------------
                                           Name:   Michael V. Monihan
                                           Title:  Vice President


                                           CANADIAN IMPERIAL BANK OF COMMERCE,
                                           as a Lender


                                           By:/s/ ELLEN MARSHALL 
                                              ----------------------------------
                                           Name:   Ellen Marshall
                                           Title:  Managing Director


                                           GENERAL ELECTRIC CAPITAL
                                           CORPORATION, as a Lender


                                           By:/s/  MARK F. MYLON
                                              ----------------------------------
                                           Name:   Mark F. Mylon
                                           Title:  Manager - Operations





                                Signature Page-2
                        Amendment No. 1 to Loan Agreement





                                           BANKBOSTON, N.A., as a Lender


                                           By:/s/ ILLEGIBLE
                                              ----------------------------------
                                           Name:
                                           Title:  Vice President


                                           CREDIT SUISSE FIRST BOSTON, as a
                                           Lender


                                           By:/s/ KRISTEN LEPRI
                                              ----------------------------------
                                           Name:  Kristin Lepri
                                           Title: Associate


                                           DRESDNER BANK AG NEW YORK AND
                                           GRAND CAYMAN BRANCHES, as a
                                           Lender


                                           By:/s/ CONSTANCE ROOSMORE
                                              ----------------------------------
                                           Name:  Constance Roosmore
                                           Title: Assistant Vice President


                                           By:/s/ LAURA FAZIO
                                              ----------------------------------
                                           Name:  Laura Fazio
                                           Title: Assistant Vice President


                                           MORGAN STANLEY SENIOR
                                           FUNDING, INC., as a Lender


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


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



                                Signature Page-3
                        Amendment No. 1 to Loan Agreement






                                           SUMMIT BANK, as a Lender


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


                                           MORGAN STANLEY DEAN WITTER
                                           PRIME INCOME TRUST, as a Lender


                                           By:/s/ ILLEGIBLE
                                              ----------------------------------
                                           Name:  ILLEGIBLE
                                           Title: AUTHORIZED SIGNATORY


                                           UNION BANK OF CALIFORNIA, as a
                                           Lender


                                           By:/s/ RYAN D. FLANAGAN
                                              ----------------------------------
                                           Name:  Ryan D. Flanagan
                                           Title: Assistant Vice President





                                Signature Page-4
                        Amendment No. 1 to Loan Agreement




                                                                     EXHIBIT H-1

                               NOTICE OF BORROWING



To:      First Union National Bank, as Agent
         Agency Services-PA4830
         1339 Chestnut Street
         Philadelphia, Pennsylvania  19107
         Facsimile no.  (215) 973-1887

         Newcourt Commercial Finance Corporation
         (f/k/a AT&T Commercial Finance Corporation),
         as Collateral Agent
         2 Gatehall Drive
         Parsippany, New Jersey  07054
         Attention:  Vice President-Operations/Media & Communication


Dated:______________________

Ladies and Gentlemen:

         The undersigned,  KMC Telecom Inc., a Delaware corporation, KMC Telecom
II, Inc.,  a Delaware  corporation,  KMC Telecom of  Virginia,  Inc., a Virginia
public service company,  KMC Telecom Leasing I LLC, a Delaware limited liability
company,  KMC Telecom Leasing II LLC, a Delaware limited liability company,  the
"Additional  Borrowers"  signatory thereto from time to time (collectively,  the
"BORROWERS"),  refer to that  certain Loan and  Security  Agreement  dated as of
December 22, 1998 among the  Borrowers,  the  financial  institutions  signatory
thereto  from  time to time (the  "LENDERS"),  First  Union  National  Bank,  as
administrative  agent for the Lenders (the "AGENT") and AT&T Commercial  Finance
Corporation,  as  collateral  agent for the  Lenders  (the  "COLLATERAL  AGENT";
together with the Agent,  the "AGENTS") (as amended,  restated,  supplemented or
otherwise  modified  from  time  to  time,  the  "LOAN  AGREEMENT";   undefined,
capitalized  terms used herein shall have the meanings  assigned  thereto in the
Loan  Agreement)  and hereby  give the Agent  notice,  irrevocably,  pursuant to
SECTION  2.03 of the Loan  Agreement  that [KMC  Telecom  Inc.] [KMC Telecom II,
Inc.] [KMC Telecom of Virginia,  Inc.] [KMC Telecom  Leasing I LLC] [KMC Telecom
Leasing  II LLC]  [Additional  Borrower]  hereby  requests a Loan under the Loan
Agreement,  and in that connection sets forth below the information  relating to
such  Loan  (the  "PROPOSED  LOAN")  as  required  by  SECTION  2.03 of the Loan
Agreement:

         (i)  The Business Day of the Proposed Loan is _________ __, ____;




                                       H-1





         (ii) The proceeds of the Proposed  Loan are to be used for the purposes
as specified on SCHEDULE A attached hereto;

          (iii) The bank account  into which the  proceeds of the Proposed  Loan
are  to  be  [credited]1[transferred]2  is  account  no.  [___________________]3
maintained at [___________]4;

          (iv) If the bank  referenced in (iii) above is not the Agent,  the ABA
number of the above-referenced bank is [___________],  and the name and address,
phone and fax numbers of the contact person at such bank, are as follows:

                                    ________________________________________
                                    ________________________________________
                                    ________________________________________
                                    Telephone Number:_______________________
                       Fax Number: ______________________;

          (v) The aggregate amount of the Proposed Loan is $[_____________];

          (vi) Such Loan,  if the initial  Loan is to bear  interest at the Base
Rate;

         (vii) Such Loan,  if after the initial Loan, is to bear interest at the
[Base Rate] [LIBO Rate,  with an applicable  Interest Period of [one month] [two
months] [three months] [six months]];

         (viii) The Borrowing Base at such time is $[________________].

         The undersigned hereby certifies that the following statements are true
on the date hereof, and will be true on the Business Day of the Proposed Loan:

         (A) The representations and warranties  contained in ARTICLE III of the
Loan  Agreement  and  contained in the other Loan  Documents  are correct in all
respects,  before  and  after  giving  effect  to the  Proposed  Loan and to the
application of the proceeds therefrom, as though made on as of such date;

         (B) No event has occurred and is continuing,  or would result from such
Proposed  Loan  or  from  the  application  of  the  proceeds  therefrom,  which
constitutes either an Event of Default or an event which but for the requirement




- - -----------------------
1  Select if the Agent is the depository bank.

2  Select if the depository bank is not the Agent.

3  Insert specific account number.

4  Insert name of financial institution.



                                       H-2





that notice be given  and/or the elapse of time,  would  constitute  an Event of
Default; and

         (C) All agreements  and all conditions to the Proposed Loan,  contained
in the Loan Agreement or any other of the Loan  Documents  which are required to
be  performed or satisfied by the Borrower on the date hereof or by the Business
Day of the Proposed Loan have been and will be performed and satisfied.

         (D) [To be  included  in the Notice of  Borrowing  at any time that the
Total  Leverage  Ratio is greater  than 6:1 as  determined  by  reference to the
financial  statements  delivered pursuant to SECTION 5.06 of the Loan Agreement]
The sum of the Proposed Loans and all other Revolving  Loans  outstanding at the
time of such  Proposed  Loan do not exceed the  Borrowing  Base and  transaction
costs  incurred  in  connection  with the  execution  and  delivery  of the Loan
Documents,  MINUS,  if the Term  Loans  have not yet been  made,  the Term  Loan
Commitment Amounts of all Term Lenders, and otherwise, the outstanding principal
balance of the Term Loans.

         (E) In addition, by its acknowledgment  signature below, the Collateral
Agent hereby confirms that the Borrowers have delivered and the Collateral Agent
has  reviewed  to its  satisfaction  (i) each of the  invoices  or  certificates
required to be provided to the Collateral  Agent pursuant to SECTION  2.03(A) of
the Loan Agreement and (ii) each of the collateral documents, including, without
limitation,  all third party  agreements and the related  consents to collateral
assignments  required  pursuant  to  SECTION  5.08  of the  Loan  Agreement,  as
requested by the Collateral Agent.



















                                       H-3





         The  undersigned  hereby  further  certifies  that in  accordance  with
SECTION 6.02 of the Loan  Agreement  the proceeds of the Proposed  Loan shall be
used only for the purposes permitted in accordance with SECTION 2.02 of the Loan
Agreement.

                                           Very truly yours,

                                           KMC TELECOM INC.
                                           KMC TELECOM II, INC.
                                           KMC TELECOM OF VIRGINIA, INC.

                                           In each case:


                                           ---------------------------
                                           By:
                                           Its:


                                           KMC TELECOM LEASING I LLC
                                           By:      KMC TELECOM INC., as Sole
                                           Member


                                           ---------------------------
                                           By:
                                           Its:


                                           KMC TELECOM LEASING II LLC
                                           By:     KMC TELECOM II, INC., as Sole
                                           Member


                                           ---------------------------
                                           By:
                                           Its:









                                       H-4









Acknowledged  and agreed  solely  with  respect to the  assertions  set forth in
section (E) above this [____] day of [______________]:

NEWCOURT COMMERCIAL FINANCE
CORPORATION
(f/k/a AT&T COMMERCIAL FINANCE
CORPORATION),
as Collateral Agent


- - ------------------------------
By:
Its:


















                                       H-5




                                   SCHEDULE A
                                       TO
                               NOTICE OF BORROWING


               DESCRIPTION OF THE PURPOSES FOR WHICH THE PROCEEDS
                        OF THE PROPOSED LOAN WILL BE USED


[If the  proceeds  of the  Proposed  Loan  will be used to fund  the  costs  and
expenses  of a System,  copies of lien  waivers and other  acknowledgments  from
Persons  constructing such System and any subcontractors or vendors with respect
to such construction,  will be required to be delivered to the Collateral Agent,
together with all applicable consents to collateral  assignments of any licenses
or leases with respect to such System.  Additionally,  any schedules to the Loan
Agreement  which,  as of the date of such proposed Loan,  require  modification,
shall be appropriately  supplemented  and delivered to the Agent.  Exceptions to
such requirements should be set forth and attached to the Notice of Borrowing.]

[If the proceeds of the Proposed  Loan will be used to purchase or reimburse any
Borrower for  Telecommunications  Equipment,  a schedule  supporting one hundred
percent (100%) of  Telecommunications  Equipment requested to be funded shall be
delivered to the  Collateral  Agent.  Such schedule will detail all invoices for
equipment,  third  party  labor,  permits,  other  third  party  costs  and  all
capitalized   internal   costs   of  the   Borrowers   with   respect   to  such
Telecommunications  Equipment  permitted  under GAAP.  All invoices over $25,000
will be attached to such schedule  delivered to the Collateral  Agent, who shall
review such invoices and verify that,  when  combined  with the above  described
capitalized  internal costs, such invoices will support at least seventy percent
(70%) of the total requested  funding.  Additionally,  any schedules to the Loan
Agreement  which,  as of the date of such Proposed Loan,  require  modification,
shall  be  supplemented  and  delivered  to  the  Agent.  In  addition,  if  the
Telecommunications  Equipment is being purchased or reimbursed  under the Lucent
Purchase  Agreement,  a  certificate  of delivery and  acceptance in the form of
EXHIBIT  R shall  be  attached  to the  Notice  of  Borrowing  delivered  to the
Collateral Agent.]

[If the  proceeds  of the  Proposed  Loan will be used to pay or  reimburse  for
transaction  costs,  a copy of the invoice  from the  provider of the service or
other appropriate  supporting  documentation must be included for the Collateral
Agent.]

[If the proceeds of the Proposed Loan will be used for working  capital or other
general  corporate  purposes,  a certificate will be required to be delivered to
the  Collateral  Agent  verifying  that the making of the Proposed Loan does not
violate any provision of the Indenture.]





                                       H-6