AMERICAN COMMUNICATIONS SERVICES, INC.
                     NON-QUALIFIED STOCK OPTION CERTIFICATE


                  A. A STOCK  OPTION  for the  purchase  of a total  of  100,000
shares of the common stock,  par value $0.01 (the "Common  Stock"),  of American
Communications  Services,  Inc. (the  "Company")  has been granted to Anthony J.
Pompliano  (the  "Optionee"),  pursuant to  subparagraph  5(c)(ii)(B) of a Third
Amended and Restated Employment  Agreement dated as of June 30, 1995 between the
Optionee  and the Company  (the  "Employment  Agreement").  This option shall be
governed by the Employment  Agreement and, except as otherwise  specifically set
forth herein,  the provisions of the Employment  Agreement  shall control in the
event of any conflict  between the terms set forth herein and the  provisions of
the  Employment  Agreement.  Unless  otherwise  defined  herein,  all  initially
capitalized  terms used herein  shall have the same  meaning as set forth in the
Employment Agreement.
                  B. The exercise price of this option is $2.25 per share (the
"Exercise Price").
                  C. This option may not be  exercised if the issuance of shares
of Common Stock of the Company upon such exercise  would  constitute a violation
of any applicable  Federal or state  securities or other law or regulation.  The
Optionee,  as a condition to his exercise of this option, shall (i) represent to
the Company that the shares of Common Stock of the Company that he acquires upon
exercise of this option are being  acquired by him for investment and not with a
view to distribution or resale,  and that he will not sell or otherwise transfer
such shares unless such


<PAGE>



shares are then registered under a currently  effective  registration  statement
under the  Securities  Act of 1933,  as amended (the "Act"),  or counsel for the
Company is then of the opinion that such  registration is not required under the
Act or any other applicable law, regulation,  or rule of any governmental agency
and (ii) if the shares of Common Stock underlying this option are not registered
under the Act,  acknowledge  that the certificate  evidencing such shares may be
stamped  with  a  restrictive   legend  and  such  shares  will  be  "restricted
securities" as defined in Rule 144 promulgated under the Act.
                  D. This option may not be transferred in any manner  otherwise
than by will or the  laws of  descent  and  distribution,  and may be  exercised
during the  lifetime of the  Optionee  only by the  Optionee.  The terms of this
option shall be binding upon the executors,  administrators,  heirs, successors,
and assigns of the Optionee.
                  E. The option shall vest and be exercisable in its entirety as
of the date hereof,  and to the extent not exercised  prior to such date,  shall
terminate and be of no further effect as of 5:00 p.m. New York City time on June
26, 2000.
                  F. The rights represented by this option may be exercised by
the Optionee by delivery of:
                  a. The exercise form annexed hereto (the "Exercise Form") duly
executed and specifying the number of shares to be purchased, to the Company at
the offices of the Company located at 131 National Business Parkway, Suite 100,
Annapolis Junction,

                                       -2-

<PAGE>



Maryland  20701  (or such  other  office  or  agency  of the  Company  as it may
designate by notice to the Optionee at the address of such Optionee appearing on
the books of the Company)  during normal  business hours on any day other than a
Saturday,  Sunday or day on which  national banks are authorized to close in the
City of New York, State of New York (a "Business Day").
                  b. Payment to the Company,  for the account of the Company, by
cash or by certified or bank cashier's  check or wire transfer,  of the Exercise
Price for the number of shares specified in the Exercise Form in lawful money of
the United States of America.
                  The  Company  agrees  that such  shares  shall be deemed to be
issued to the Optionee as the record owner of such shares as of the commencement
of  business on the date on which this option  shall have been  surrendered  and
payment made for the shares as aforesaid.  Certificates for the shares specified
in the  Exercise  Form  shall  be  delivered  to the  Optionee  as  promptly  as
practicable,  and in any event within ten (10) days  thereafter.  If this option
shall  have been  exercised  only in part,  the  Company  shall,  at the time of
delivery of the certificate or certificates delivered to the Optionee, deliver a
new option  evidencing the right to purchase the remaining shares issuable under
this option,  which new option shall in all other  respects be identical to this
option.  No  adjustment  shall be made on shares  issuable  on  exercise of this
option  for any cash  dividends  paid or  payable to holders of record of Common
Stock out of consolidated earnings or earned surplus prior to the date as

                                       -3-

<PAGE>



of which the Optionee shall be deemed to be the record-holder of such shares.
                  G.       Certain Adjustments.
                  G.1 The number of shares purchasable upon the exercise of this
option and the Exercise Price shall be subject to adjustment as follows:
                  (a) In case the Company  shall (i) pay a dividend in shares of
Common Stock or make a  distribution  in shares of Common Stock,  (ii) subdivide
its outstanding shares of Common Stock (including, without limitation, by way of
stock splits and the like), (iii) combine its outstanding shares of Common Stock
into  a  smaller   number  of   shares  of  Common   Stock  or  (iv)   issue  by
reclassification  of its shares of Common Stock other  securities of the Company
(including  any such  reclassification  in connection  with a  consolidation  or
merger in which the Company is the surviving corporation),  the number of shares
purchasable  upon  exercise of this option  immediately  prior  thereto shall be
adjusted so that the  Optionee  shall be entitled to receive the kind and number
of shares or other  securities  of the Company which he would have owned or have
been  entitled to receive  after the  happening  of any of the events  described
above had this option been exercised  immediately prior to the happening of such
event or any record date with respect  thereto.  An adjustment  made pursuant to
this paragraph (a) shall become effective  immediately  after the effective date
of each such event  retroactive  to the record  date,  if any,  for such  event,
without amendment or modification required to this document.

                                       -4-

<PAGE>



                  (b) In  case  the  Company  shall  issue  rights,  options  or
warrants to all or  substantially  all holders of its outstanding  Common Stock,
without any charge to such holders,  entitling them to subscribe for or purchase
shares of Common  Stock at a price per share  which is lower at the record  date
mentioned below than the then current market price per share of Common Stock (as
defined in paragraph  (d) below),  the number of shares  thereafter  purchasable
upon the exercise of this option shall be determined by  multiplying  the number
of shares theretofore purchasable upon exercise of this option by a fraction, of
which the numerator shall be the number of shares of Common Stock outstanding on
the date of issuance  of such  rights,  options or  warrants  plus the number of
additional  shares of Common Stock offered for subscription or purchase,  and of
which the denominator  shall be the number of shares of Common Stock outstanding
on the date of issuance of such rights,  options or warrants  plus the number of
shares  which the  aggregate  offering  price of the  total  number of shares of
Common Stock so offered would  purchase at the current market price per share of
Common Stock at such record date.  Such  adjustment  shall be made whenever such
rights,  options or warrants are issued, and shall become effective  immediately
after the record date for the determination of stockholders  entitled to receive
such rights, options or warrants.
                  (c)      In case the Company shall distribute to all or
substantially all holders of its shares of Common Stock evidences of its
indebtedness or assets (excluding cash dividends or

                                       -5-

<PAGE>



distributions  payable  out of  consolidated  earnings  or  earned  surplus  and
dividends  or  distributions  referred  to in  paragraph  (a)  above) or rights,
options or warrants,  or convertible or exchangeable  securities  containing the
right to  subscribe  for or purchase  shares of Common  Stock  (excluding  those
referred  to in  paragraph  (b)  above),  then in each case the number of shares
thereafter  purchasable  upon the exercise of this option shall be determined by
multiplying the number of shares  theretofore  purchasable  upon the exercise of
this  option by a fraction,  of which the  numerator  shall be the then  current
market price per share of Common  Stock (as defined in  paragraph  (d) below) on
the date of such  distribution,  and of which the denominator  shall be the then
current  market  price per share of Common  Stock,  less the then fair value (as
determined  in good  faith  by the  Board of  Directors  of the  Company,  or if
requested by the Optionee,  by a leading firm of investment  bankers selected by
the Optionee and reasonably  acceptable to the Company and whose reasonable fees
and  expenses  shall be paid by the Company or as  otherwise  agreed upon by the
Company  and the  Optionee),  of the  portion  of the  assets  or  evidences  of
indebtedness so distributed or of such subscription rights, options or warrants,
or of such  convertible or exchangeable  securities,  applicable to one share of
Common Stock.  Such adjustment  shall be made whenever any such  distribution is
made, and shall become effective on the date of distribution  retroactive to the
record date for the  determination  of  shareholders  entitled  to receive  such
distribution.

                                       -6-

<PAGE>



                  (d) For the purpose of  computation  under (b) and (c) of this
paragraph  G.1,  the current  market price per share of Common Stock at any date
shall be:
                           (x) from and after 30 trading days after consummation
                  of a  Qualifying  Offering  (as such  term is  defined  in the
                  Company's  Certificate  of  Incorporation,  as  amended),  the
                  average of the daily  closing  prices  for the 30  consecutive
                  trading  days  immediately  preceding  such  computation.  The
                  closing  price for each day shall be the last  reported  sales
                  price  regular  way or, in case no such  reported  sale  takes
                  place on such day,  the  average of the  closing bid and asked
                  prices regular way for such day, in each case on the principal
                  national  securities  exchange  on which the  shares of Common
                  Stock are listed or admitted  to  trading,  or, if reported on
                  NASDAQ-National  Market System, the last reported sales price,
                  or, if not so listed or admitted to trading or  reported,  the
                  average  of the  closing  bid and asked  prices of the  Common
                  Stock in the over-the-counter  market as reported by NASDAQ or
                  any comparable system; and
                           (y) on or prior to the  expiration  of the 30 trading
                  day  period set forth in clause  (x)  above,  the fair  market
                  value per share of Common Stock  determined  by a leading firm
                  of investment  bankers selected by the Optionee and reasonably
                  acceptable  to the  Company  and  whose  reasonable  fees  and
                  expenses shall be paid by the Company.

                                       -7-

<PAGE>



                  (e)  No  adjustment  in  the  number  of  shares   purchasable
hereunder shall be required unless such adjustment  would require an increase or
decrease of at least one percent (1%) in the number of shares  purchasable  upon
the exercise of this option;  provided,  however,  that any adjustments which by
reason  of this  paragraph  (e) are not  required  to be made  shall be  carried
forward and taken into account in any subsequent  adjustment.  All  calculations
shall be made to the nearest one-thousandth of a share.
                  (f)  Whenever  the  number  of  shares  purchasable  upon  the
exercise of this option is adjusted,  as herein  provided,  the  Exercise  Price
payable upon the exercise of this option shall be adjusted by  multiplying  such
Exercise Price immediately prior to such adjustment by a fraction,  of which the
numerator  shall be the number of shares  purchasable  upon the exercise of this
option immediately prior to such adjustment,  and of which the denominator shall
be the number of shares purchasable immediately thereafter.
                  (g) No adjustment in the number of shares purchasable upon the
exercise of this option need be made under paragraphs (b) and (c) if the Company
issues  or  distributes  to the  Optionee  the  rights,  options,  warrants,  or
convertible or exchangeable  securities,  or evidences of indebtedness or assets
referred to in those  paragraphs  which the Optionee would have been entitled to
receive had the option been  exercised  prior to the  happening of such event or
the record date with  respect  thereto.  No  adjustment  in the number of shares
purchasable  upon the  exercise  of this  option  may be made for sale of shares
pursuant to a Company plan

                                       -8-

<PAGE>



for reinvestment of dividends or interest.  No adjustment need be made for a
change in the par value of the shares.
                  (h) The Company shall not, by amendment of its  Certificate of
Incorporation  or through  any  reorganization,  recapitalization,  transfer  of
assets, consolidation, merger, dissolution, issue or sale of securities, rights,
options or warrants or any other  voluntary  action,  avoid or seek to avoid the
observance or performance of any of the terms to be observed or performed  under
this paragraph G.1 by the Company, but will at all times in good faith assist in
carrying out all of the  provisions  of this  paragraph G.1 and in the taking of
such actions as may be necessary or  appropriate  in order to protect the rights
of the Optionee under this paragraph G.1 against impairment.
                  (i) For the purpose of this paragraph G.1, the term "shares of
Common  Stock" shall mean (i) the class of stock  designated as the common stock
of the Company at the date of this Certificate, or (ii) any other class of stock
resulting from successive changes or  reclassification of such shares consisting
solely of changes in par value,  or from par value to no par value. In the event
that at any time,  as a result of an  adjustment  made pursuant to paragraph (a)
above,  the Optionee  shall become  entitled to purchase any  securities  of the
Company other than shares of Common Stock,  thereafter  the number of such other
shares so  purchasable  upon exercise of this option,  and the Exercise Price of
such shares, shall be subject to adjustment from time to time in a manner and on
terms as nearly equivalent as practicable to the

                                       -9-

<PAGE>



provisions  with respect to the shares  contained in paragraphs (a) through (h),
inclusive, above, and the paragraphs G.2 through G.4, inclusive, with respect to
the shares, shall apply on like terms to any such other securities.
                  (j) Upon the  expiration of any rights,  options,  warrants or
conversion or exchange privileges, if any thereof shall not have been exercised,
the Exercise  Price and the number of shares  shall,  upon such  expiration,  be
readjusted  and  shall  thereafter  be such as it  would  have  been had it been
originally  adjusted (or had the original  adjustment not been required,  as the
case may be),  as if (A) the only  shares  of Common  Stock so  issued  were the
shares of Common  Stock,  if any,  actually  issued or sold upon the exercise of
such rights,  options,  warrants or conversion  or exchange  rights and (B) such
shares of  Common  Stock,  if any,  were  issued  or sold for the  consideration
actually  received  by  the  Company  upon  such  exercise  plus  the  aggregate
consideration,  if any, actually received by the Company for the issuance,  sale
or grant of all such rights, options,  warrants or conversion or exchange rights
whether or not exercised;  provided,  further,  that no such readjustment  shall
have the effect of increasing  the Exercise  Price or  decreasing  the number of
shares by an amount in excess of the amount of the adjustment  initially made in
respect to the  issuance,  sale or grant of such  rights,  options,  warrants or
conversion or exchange rights.
                  G.2. Notice of Adjustment.  Whenever the number of shares or
the Exercise Price payable upon exercise of this option is

                                      -10-

<PAGE>



adjusted,  as herein  provided,  the Company shall promptly mail by first class,
postage prepaid, to the Optionee, notice of such adjustment or adjustments and a
certificate of a firm of independent public accountants selected by the Board of
Directors  of the Company  (who may be the regular  accountants  employed by the
Company)  setting forth the number of shares and the Exercise Price payable upon
exercise of this option after such  adjustment,  setting forth a brief statement
of the facts  requiring  such  adjustment  and setting forth the  computation by
which such adjustment was made.
                  G.3. No Adjustment for Dividends.  Except as provided in
paragraph G.1, no adjustment in respect of any dividends shall be made during
the term of this option or upon the exercise of this option.
                  G.4. Preservation   of   Purchase   Rights   Upon   Merger,
Consolidation,  etc. In case of any  consolidation of the Company with or merger
of the Company  into  another  corporation  or otherwise or in case of any sale,
transfer  or  lease  to  another  corporation  of all or  substantially  all the
property  of  the  Company,   the  Company  or  such   successor  or  purchasing
corporation,  as the case may be,  shall  execute with the Optionee an agreement
that the Optionee shall have the right  thereafter  upon payment of the Exercise
Price in effect  immediately  prior to such action to purchase  upon exercise of
this  option  the kind and amount of shares and other  securities  and  property
which such holder  would have owned or have been  entitled to receive  after the
happening of such consolidation, merger, sale, transfer or lease had this option
been exercised

                                      -11-

<PAGE>



immediately prior to such action, provided that such agreement shall provide for
adjustments  thereafter,   which  shall  be  as  nearly  equivalent  as  may  be
practicable to the adjustments  provided for in this paragraph G. The provisions
of this paragraph G shall similarly apply to successive consolidations, mergers,
sales, transfers or leases.
         H.  Registration Rights.  Optionee shall have the registration rights
with respect to this option as set forth in the Amended and Restated
Registration Rights Agreement dated as of June 30, 1995 and entered into by and
among the Company, the Optionee and the other executive officers of the Company
set forth therein.

                                          AMERICAN COMMUNICATIONS SERVICES, INC.

                                          By: /s/ RICHARD A. KOZAK
                                               Richard A. Kozak
                                               President and Chief Operating
                                                  Officer


Dated as of:  As of June 30, 1995





ATTEST:   /s/ RILEY M. MURPHY,
          Riley M. Murphy, Secretary

                                      -12-

<PAGE>



                                  PURCHASE FORM


                                                                 Date: _________



         TO:  Chief Financial Officer

         The  undersigned  hereby  irrevocably  elects to exercise  the attached
         Non-Qualified  Stock  Option  Certificate  to the  extent of options to
         purchase  _______  shares and hereby makes payment of $_____ in payment
         of the purchase price thereof.

                  INSTRUCTIONS FOR REGISTRATION OF SECURITIES

                  Name:____________________________________

                  Address:_________________________________
                          ---------------------------------



                                                           ---------------------

                                      -13-

<PAGE>



                     AMERICAN COMMUNICATIONS SERVICES, INC.
                     NON-QUALIFIED STOCK OPTION CERTIFICATE


                  A. A STOCK OPTION for the purchase of a total of 50,000 shares
of the  common  stock,  par  value  $0.01  (the  "Common  Stock"),  of  American
Communications  Services,  Inc. (the  "Company")  has been granted to Anthony J.
Pompliano  (the  "Optionee"),  pursuant to  subparagraph  5(c)(ii)(A) of a Third
Amended and Restated Employment  Agreement dated as of June 30, 1995 between the
Optionee  and the Company  (the  "Employment  Agreement").  This option shall be
governed by the Employment  Agreement and, except as otherwise  specifically set
forth herein,  the provisions of the Employment  Agreement  shall control in the
event of any conflict  between the terms set forth herein and the  provisions of
the  Employment  Agreement.  Unless  otherwise  defined  herein,  all  initially
capitalized  terms used herein  shall have the same  meaning as set forth in the
Employment Agreement.
                  B. The exercise price of this option is $2.25 per share (the
"Exercise Price").
                  C. This option may not be  exercised if the issuance of shares
of Common Stock of the Company upon such exercise  would  constitute a violation
of any applicable  Federal or state  securities or other law or regulation.  The
Optionee,  as a condition to his exercise of this option, shall (i) represent to
the Company that the shares of Common Stock of the Company that he acquires upon
exercise of this option are being  acquired by him for investment and not with a
view to distribution or resale, and that

                                       -1-

<PAGE>



he will not sell or otherwise  transfer  such shares unless such shares are then
registered  under  a  currently  effective   registration  statement  under  the
Securities  Act of 1933,  as amended (the "Act"),  or counsel for the Company is
then of the opinion that such  registration is not required under the Act or any
other applicable law, regulation, or rule of any governmental agency and (ii) if
the shares of Common Stock  underlying this option are not registered  under the
Act, acknowledge that the certificate evidencing such shares may be stamped with
a restrictive legend and such shares will be "restricted  securities" as defined
in Rule 144 promulgated under the Act.
                  D. This option may not be transferred in any manner  otherwise
than by will or the  laws of  descent  and  distribution,  and may be  exercised
during the  lifetime of the  Optionee  only by the  Optionee.  The terms of this
option shall be binding upon the executors,  administrators,  heirs, successors,
and assigns of the Optionee.
                  E. The option shall vest and be exercisable in its entirety as
of the date hereof,  and to the extent not exercised  prior to such date,  shall
terminate  and be of no  further  effect as of 5:00  p.m.  New York City time on
October 20, 1999.
                  F. The rights represented by this option may be exercised by
the Optionee by delivery of:
                  a. the exercise form annexed hereto (the "Exercise Form") duly
executed and specifying the number of shares to be purchased, to the Company at
the offices of the Company located at

                                       -2-

<PAGE>



131 National Business Parkway, Suite 100, Annapolis Junction, Maryland 20701 (or
such other office or agency of the Company as it may  designate by notice to the
Optionee at the address of such Optionee  appearing on the books of the Company)
during normal business hours on any day other than a Saturday,  Sunday or day on
which national  banks are authorized to close in the City of New York,  State of
New York (a "Business Day").
                  b. Payment to the Company,  for the account of the Company, by
cash or by certified or bank cashier's  check or wire transfer,  of the Exercise
Price for the number of shares specified in the Exercise Form in lawful money of
the United States of America.
                  The  Company  agrees  that such  shares  shall be deemed to be
issued to the Optionee as the record owner of such shares as of the commencement
of  business on the date on which this option  shall have been  surrendered  and
payment made for the shares as aforesaid.  Certificates for the shares specified
in the  Exercise  Form  shall  be  delivered  to the  Optionee  as  promptly  as
practicable,  and in any event within ten (10) days  thereafter.  If this option
shall  have been  exercised  only in part,  the  Company  shall,  at the time of
delivery of the certificate or certificates delivered to the Optionee, deliver a
new option  evidencing the right to purchase the remaining shares issuable under
this option,  which new option shall in all other  respects be identical to this
option.  No  adjustment  shall be made on shares  issuable  on  exercise of this
option  for any cash  dividends  paid or  payable to holders of record of Common
Stock

                                       -3-

<PAGE>



out of consolidated earnings or earned surplus prior to the date as of which the
Optionee shall be deemed to be the record-holder of such shares.
                  G.  Certain Adjustments.
                  G.1 The number of shares purchasable upon the exercise of this
option and the Exercise Price shall be subject to adjustment as follows:
                  (a) In case the Company  shall (i) pay a dividend in shares of
Common Stock or make a  distribution  in shares of Common Stock,  (ii) subdivide
its outstanding shares of Common Stock (including, without limitation, by way of
stock splits and the like), (iii) combine its outstanding shares of Common Stock
into  a  smaller   number  of   shares  of  Common   Stock  or  (iv)   issue  by
reclassification  of its shares of Common Stock other  securities of the Company
(including  any such  reclassification  in connection  with a  consolidation  or
merger in which the Company is the surviving corporation),  the number of shares
purchasable  upon  exercise of this option  immediately  prior  thereto shall be
adjusted so that the  Optionee  shall be entitled to receive the kind and number
of shares or other  securities  of the Company which he would have owned or have
been  entitled to receive  after the  happening  of any of the events  described
above had this option been exercised  immediately prior to the happening of such
event or any record date with respect  thereto.  An adjustment  made pursuant to
this paragraph (a) shall become effective  immediately  after the effective date
of each

                                       -4-

<PAGE>



such event  retroactive  to the record  date,  if any,  for such event,  without
amendment or modification required to this document.
                  (b) In  case  the  Company  shall  issue  rights,  options  or
warrants to all or  substantially  all holders of its outstanding  Common Stock,
without any charge to such holders,  entitling them to subscribe for or purchase
shares of Common  Stock at a price per share  which is lower at the record  date
mentioned below than the then current market price per share of Common Stock (as
defined in paragraph  (d) below),  the number of shares  thereafter  purchasable
upon the exercise of this option shall be determined by  multiplying  the number
of shares theretofore purchasable upon exercise of this option by a fraction, of
which the numerator shall be the number of shares of Common Stock outstanding on
the date of issuance  of such  rights,  options or  warrants  plus the number of
additional  shares of Common Stock offered for subscription or purchase,  and of
which the denominator  shall be the number of shares of Common Stock outstanding
on the date of issuance of such rights,  options or warrants  plus the number of
shares  which the  aggregate  offering  price of the  total  number of shares of
Common Stock so offered would  purchase at the current market price per share of
Common Stock at such record date.  Such  adjustment  shall be made whenever such
rights,  options or warrants are issued, and shall become effective  immediately
after the record date for the determination of stockholders  entitled to receive
such rights, options or warrants.

                                       -5-

<PAGE>



                  (c) In  case  the  Company   shall   distribute   to  all  or
substantially  all  holders  of its  shares of  Common  Stock  evidences  of its
indebtedness or assets (excluding cash dividends or distributions payable out of
consolidated earnings or earned surplus and dividends or distributions  referred
to in paragraph (a) above) or rights,  options or warrants,  or  convertible  or
exchangeable securities containing the right to subscribe for or purchase shares
of Common Stock  (excluding  those referred to in paragraph (b) above),  then in
each case the number of shares thereafter  purchasable upon the exercise of this
option  shall be  determined  by  multiplying  the number of shares  theretofore
purchasable  upon the  exercise  of this  option  by a  fraction,  of which  the
numerator  shall be the then current  market price per share of Common Stock (as
defined in paragraph (d) below) on the date of such  distribution,  and of which
the  denominator  shall be the then  current  market  price  per share of Common
Stock,  less the then fair  value (as  determined  in good faith by the Board of
Directors of the Company, or if requested by the Optionee,  by a leading firm of
investment  bankers  selected by the Optionee and  reasonably  acceptable to the
Company and whose  reasonable  fees and expenses shall be paid by the Company or
as otherwise agreed upon by the Company and the Optionee), of the portion of the
assets or evidences  of  indebtedness  so  distributed  or of such  subscription
rights, options or warrants, or of such convertible or exchangeable  securities,
applicable to one share of Common Stock.  Such adjustment shall be made whenever
any such distribution is made,

                                       -6-

<PAGE>



and shall become effective on the date of distribution retroactive to the record
date  for  the   determination   of   shareholders   entitled  to  receive  such
distribution.
                  (d) For the purpose of  computation  under (b) and (c) of this
paragraph  G.1,  the current  market price per share of Common Stock at any date
shall be:
                           (x) from and after 30 trading days after consummation
                  of a  Qualifying  Offering  (as such  term is  defined  in the
                  Company's  Certificate  of  Incorporation,  as  amended),  the
                  average of the daily  closing  prices  for the 30  consecutive
                  trading  days  immediately  preceding  such  computation.  The
                  closing  price for each day shall be the last  reported  sales
                  price  regular  way or, in case no such  reported  sale  takes
                  place on such day,  the  average of the  closing bid and asked
                  prices regular way for such day, in each case on the principal
                  national  securities  exchange  on which the  shares of Common
                  Stock are listed or admitted  to  trading,  or, if reported on
                  NASDAQ-National  Market System, the last reported sales price,
                  or, if not so listed or admitted to trading or  reported,  the
                  average  of the  closing  bid and asked  prices of the  Common
                  Stock in the over-the-counter  market as reported by NASDAQ or
                  any comparable system; and
                           (y) on or prior to the expiration of the 30 trading
                  day period set forth in clause (x) above, the fair market
                  value per share of Common Stock determined by a leading

                                       -7-

<PAGE>



                  firm of investment bankers selected by the Optionee and
                  reasonably acceptable to the Company and whose reasonable
                  fees and expenses shall be paid by the Company.
                  (e) No adjustment in the number of shares purchasable
hereunder shall be required unless such adjustment  would require an increase or
decrease of at least one percent (1%) in the number of shares  purchasable  upon
the exercise of this option;  provided,  however,  that any adjustments which by
reason  of this  paragraph  (e) are not  required  to be made  shall be  carried
forward and taken into account in any subsequent  adjustment.  All  calculations
shall be made to the nearest one-thousandth of a share.
                  (f) Whenever  the  number  of  shares  purchasable  upon  the
exercise of this option is adjusted,  as herein  provided,  the  Exercise  Price
payable upon the exercise of this option shall be adjusted by  multiplying  such
Exercise Price immediately prior to such adjustment by a fraction,  of which the
numerator  shall be the number of shares  purchasable  upon the exercise of this
option immediately prior to such adjustment,  and of which the denominator shall
be the number of shares purchasable immediately thereafter.
                  (g) No adjustment in the number of shares purchasable upon the
exercise of this option need be made under paragraphs (b) and (c) if the Company
issues  or  distributes  to the  Optionee  the  rights,  options,  warrants,  or
convertible or exchangeable  securities,  or evidences of indebtedness or assets
referred to in those  paragraphs  which the Optionee would have been entitled to
receive had the option been exercised prior to the happening of

                                       -8-

<PAGE>



such event or the record date with respect thereto.  No adjustment in the number
of shares  purchasable  upon the exercise of this option may be made for sale of
shares pursuant to a Company plan for reinvestment of dividends or interest.  No
adjustment need be made for a change in the par value of the shares.
                  (h) The Company shall not, by amendment of its  Certificate of
Incorporation  or through  any  reorganization,  recapitalization,  transfer  of
assets, consolidation, merger, dissolution, issue or sale of securities, rights,
options or warrants or any other  voluntary  action,  avoid or seek to avoid the
observance or performance of any of the terms to be observed or performed  under
this paragraph G.1 by the Company, but will at all times in good faith assist in
carrying out all of the  provisions  of this  paragraph G.1 and in the taking of
such actions as may be necessary or  appropriate  in order to protect the rights
of the Optionee under this paragraph G.1 against impairment.
                  (i) For the purpose of this paragraph G.1, the term "shares of
Common  Stock" shall mean (i) the class of stock  designated as the common stock
of the Company at the date of this Certificate, or (ii) any other class of stock
resulting from successive changes or  reclassification of such shares consisting
solely of changes in par value,  or from par value to no par value. In the event
that at any time,  as a result of an  adjustment  made pursuant to paragraph (a)
above,  the Optionee  shall become  entitled to purchase any  securities  of the
Company other than shares of Common Stock,  thereafter  the number of such other
shares so

                                       -9-

<PAGE>



purchasable upon exercise of this option, and the Exercise Price of such shares,
shall be  subject  to  adjustment  from time to time in a manner and on terms as
nearly  equivalent as practicable  to the provisions  with respect to the shares
contained in paragraphs (a) through (h),  inclusive,  above,  and the paragraphs
G.2 through  G.4,  inclusive,  with  respect to the shares,  shall apply on like
terms to any such other securities.
                  (j) Upon the  expiration of any rights,  options,  warrants or
conversion or exchange privileges, if any thereof shall not have been exercised,
the Exercise  Price and the number of shares  shall,  upon such  expiration,  be
readjusted  and  shall  thereafter  be such as it  would  have  been had it been
originally  adjusted (or had the original  adjustment not been required,  as the
case may be),  as if (A) the only  shares  of Common  Stock so  issued  were the
shares of Common  Stock,  if any,  actually  issued or sold upon the exercise of
such rights,  options,  warrants or conversion  or exchange  rights and (B) such
shares of  Common  Stock,  if any,  were  issued  or sold for the  consideration
actually  received  by  the  Company  upon  such  exercise  plus  the  aggregate
consideration,  if any, actually received by the Company for the issuance,  sale
or grant of all such rights, options,  warrants or conversion or exchange rights
whether or not exercised;  provided,  further,  that no such readjustment  shall
have the effect of increasing  the Exercise  Price or  decreasing  the number of
shares by an amount in excess of the amount of the adjustment  initially made in
respect to the issuance,

                                      -10-

<PAGE>



sale or grant of such rights, options, warrants or conversion or exchange
rights.
                  G.2. Notice of  Adjustment.  Whenever the number of shares or
the Exercise  Price payable upon exercise of this option is adjusted,  as herein
provided,  the Company shall promptly mail by first class,  postage prepaid,  to
the Optionee,  notice of such  adjustment or adjustments  and a certificate of a
firm of independent public accountants selected by the Board of Directors of the
Company (who may be the regular  accountants  employed by the  Company)  setting
forth the number of shares and the Exercise  Price payable upon exercise of this
option  after such  adjustment,  setting  forth a brief  statement  of the facts
requiring  such  adjustment  and  setting  forth the  computation  by which such
adjustment was made.
                  G.3. No Adjustment for Dividends.  Except as provided in
paragraph G.1, no adjustment in respect of any dividends shall be made during
the term of this option or upon the exercise of this option.
                  G.4. Preservation   of   Purchase   Rights   Upon   Merger,
Consolidation,  etc. In case of any  consolidation of the Company with or merger
of the Company  into  another  corporation  or otherwise or in case of any sale,
transfer  or  lease  to  another  corporation  of all or  substantially  all the
property  of  the  Company,   the  Company  or  such   successor  or  purchasing
corporation,  as the case may be,  shall  execute with the Optionee an agreement
that the Optionee shall have the right  thereafter  upon payment of the Exercise
Price in effect immediately prior to such action to purchase upon

                                      -11-

<PAGE>



exercise of this option the kind and amount of shares and other  securities  and
property  which such  holder  would have owned or have been  entitled to receive
after the happening of such consolidation,  merger,  sale, transfer or lease had
this option been exercised immediately prior to such action,  provided that such
agreement  shall provide for  adjustments  thereafter,  which shall be as nearly
equivalent  as may  be  practicable  to the  adjustments  provided  for in  this
paragraph  G.  The  provisions  of this  paragraph  G shall  similarly  apply to
successive consolidations, mergers, sales, transfers or leases.
                  H. Registration Rights.  Optionee shall have the registration
rights with respect to this option as set forth in the Amended and Restated
Registration Rights Agreement dated as of June 30, 1995 and entered into by and
among the Company, the Optionee and the other executive officers of the Company
set forth therein.

                                          AMERICAN COMMUNICATIONS SERVICES, INC.

                                          By: /s/ RICHARD A. KOZAK
                                              Richard A. Kozak
                                              President and Chief Operating
                                                  Officer
     

Dated as of:  As of June 30, 1995



ATTEST:   /s/ RILEY M. MURPHY,
          Riley M. Murphy, Secretary

                                      -12-

<PAGE>



                                  PURCHASE FORM


                                                                 Date: _________



         TO:  Chief Financial Officer

         The  undersigned  hereby  irrevocably  elects to exercise  the attached
         Non-Qualified  Stock  Option  Certificate  to the  extent of options to
         purchase  _______  shares and hereby makes payment of $_____ in payment
         of the purchase price thereof.

                  INSTRUCTIONS FOR REGISTRATION OF SECURITIES

                  Name:____________________________________

                  Address:_________________________________
                          ---------------------------------



                                                           ---------------------

                                      -13-

<PAGE>



                     AMERICAN COMMUNICATIONS SERVICES, INC.
                     NON-QUALIFIED STOCK OPTION CERTIFICATE



                  A. A STOCK  OPTION for the  purchase  of a total of  1,349,899
shares of the common stock,  par value $0.01 (the "Common  Stock"),  of American
Communications  Services,  Inc. (the  "Company")  has been granted to Anthony J.
Pompliano (the "Optionee"),  pursuant to subparagraph 5(c)(i) of a Third Amended
and Restated Employment Agreement dated as of June 30, 1995 between the Optionee
and the Company (the "Employment  Agreement").  This option shall be governed by
the Employment Agreement and, except as otherwise specifically set forth herein,
the  provisions of the  Employment  Agreement  shall control in the event of any
conflict between the terms set forth herein and the provisions of the Employment
Agreement. Unless otherwise defined herein, all initially capitalized terms used
herein shall have the same meaning as set forth in the Employment Agreement.
                  B.       The exercise price of this option is $0.875 per
share (the "Exercise Price").
                  C. This option may not be  exercised if the issuance of shares
of Common Stock of the Company upon such exercise  would  constitute a violation
of any applicable  Federal or state  securities or other law or regulation.  The
Optionee,  as a condition to his exercise of this option, shall (i) represent to
the Company that the shares of Common Stock of the Company that he acquires upon
exercise of this option are being  acquired by him for investment and not with a
view to distribution or resale, and that

                                       -1-

<PAGE>



he will not sell or otherwise  transfer  such shares unless such shares are then
registered  under  a  currently  effective   registration  statement  under  the
Securities  Act of 1933,  as amended (the "Act"),  or counsel for the Company is
then of the opinion that such  registration is not required under the Act or any
other applicable law, regulation, or rule of any governmental agency and (ii) if
the shares of Common Stock  underlying this option are not registered  under the
Act, acknowledge that the certificate evidencing such shares may be stamped with
a restrictive legend and such shares will be "restricted  securities" as defined
in Rule 144 promulgated under the Act.
                  D. This option may not be transferred in any manner  otherwise
than by will or the  laws of  descent  and  distribution,  and may be  exercised
during the  lifetime of the  Optionee  only by the  Optionee.  The terms of this
option shall be binding upon the executors,  administrators,  heirs, successors,
and assigns of the Optionee.
                  E. The option shall be exercisable as follows:
                    (i)  The option shall not be exercisable, and to the
extent not exercised  prior to such date,  shall  terminate and be of no further
effect as of 5:00 p.m. New York City time on the respective expiration dates set
forth below.
                   (ii) The option  shall be  exercisable  as to 449,967  shares
commencing as of August 24, 1993 and shall expire on August 23, 2000.

                                       -2-

<PAGE>



                  (iii) The  option  shall be  exercisable  as to an  additional
449,966  shares  commencing  on January 1, 1995 and shall expire on December 31,
2000.
                   (iv) The  option  shall be  exercisable  as to the  remaining
449,966  shares  commencing on the sooner of (1) the time the Company's  seventh
(7th) competitive  access network becomes  operational,  or (ii) August 23, 1996
and shall expire on the day immediately preceding the fifth (5th) anniversary of
such vesting date.
                  F. Notwithstanding the foregoing,  the option shall not become
exercisable  as to a tranche of shares if Optionee is  terminated  For Cause (as
defined  in  paragraph  11 of the  Employment  Agreement)  prior to the date the
option becomes exercisable as to such shares as set forth in paragraph E hereof.
                  G. Subject to the provisions of paragraphs E and F, the rights
represented by this option may be exercised by the Optionee by delivery of:
                  a. the exercise form annexed hereto (the "Exercise Form") duly
executed and specifying the number of shares to be purchased,  to the Company at
the offices of the Company located at 131 National Business Parkway,  Suite 100,
Annapolis  Junction,  Maryland  20701  (or such  other  office  or agency of the
Company as it may  designate  by notice to the  Optionee  at the address of such
Optionee  appearing on the books of the Company) during normal business hours on
any day other than a Saturday, Sunday or day on

                                       -3-

<PAGE>



which national  banks are authorized to close in the City of New York,  State of
New York (a "Business Day").
                  b. Payment to the Company,  for the account of the Company, by
cash or by certified or bank cashier's  check or wire transfer,  of the Exercise
Price for the number of shares specified in the Exercise Form in lawful money of
the United States of America.
                  The  Company  agrees  that such  shares  shall be deemed to be
issued to the Optionee as the record owner of such shares as of the commencement
of  business on the date on which this option  shall have been  surrendered  and
payment made for the shares as aforesaid.  Certificates for the shares specified
in the  Exercise  Form  shall  be  delivered  to the  Optionee  as  promptly  as
practicable,  and in any event within ten (10) days  thereafter.  If this option
shall  have been  exercised  only in part,  the  Company  shall,  at the time of
delivery of the certificate or certificates delivered to the Optionee, deliver a
new option  evidencing the right to purchase the remaining shares issuable under
this option,  which new option shall in all other  respects be identical to this
option.  No  adjustment  shall be made on shares  issuable  on  exercise of this
option  for any cash  dividends  paid or  payable to holders of record of Common
Stock out of  consolidated  earnings or earned  surplus  prior to the date as of
which the Optionee shall be deemed to be the record-holder of such shares.
                  H.       Certain Adjustments.
                           --------------------

                                       -4-

<PAGE>



                  H.1.  The number of shares  purchasable  upon the  exercise of
this option and the Exercise Price shall be subject to adjustment as follows:
                  (a) In case the Company  shall (i) pay a dividend in shares of
Common Stock or make a  distribution  in shares of Common Stock,  (ii) subdivide
its outstanding shares of Common Stock (including, without limitation, by way of
stock splits and the like), (iii) combine its outstanding shares of Common Stock
into  a  smaller   number  of   shares  of  Common   Stock  or  (iv)   issue  by
reclassification  of its shares of Common Stock other  securities of the Company
(including  any such  reclassification  in connection  with a  consolidation  or
merger in which the Company is the surviving corporation),  the number of shares
purchasable  upon  exercise of this option  immediately  prior  thereto shall be
adjusted so that the  Optionee  shall be entitled to receive the kind and number
of shares or other  securities  of the Company which he would have owned or have
been  entitled to receive  after the  happening  of any of the events  described
above had this option been exercised  immediately prior to the happening of such
event or any record date with respect  thereto.  An adjustment  made pursuant to
this paragraph (a) shall become effective  immediately  after the effective date
of each such event  retroactive  to the record  date,  if any,  for such  event,
without amendment or modification required to this document.
                  (b) In  case  the  Company  shall  issue  rights,  options  or
warrants to all or  substantially  all holders of its outstanding  Common Stock,
without any charge to such holders, entitling them to

                                       -5-

<PAGE>



subscribe  for or purchase  shares of Common Stock at a price per share which is
lower at the record date mentioned  below than the then current market price per
share of Common Stock (as defined in paragraph (d) below),  the number of shares
thereafter  purchasable  upon the exercise of this option shall be determined by
multiplying the number of shares  theretofore  purchasable upon exercise of this
option by a fraction,  of which the  numerator  shall be the number of shares of
Common  Stock  outstanding  on the date of issuance of such  rights,  options or
warrants  plus the  number of  additional  shares of Common  Stock  offered  for
subscription or purchase,  and of which the  denominator  shall be the number of
shares of Common  Stock  outstanding  on the date of  issuance  of such  rights,
options or warrants plus the number of shares which the aggregate offering price
of the total number of shares of Common Stock so offered  would  purchase at the
current  market  price per  share of  Common  Stock at such  record  date.  Such
adjustment  shall be made whenever such rights,  options or warrants are issued,
and  shall  become  effective   immediately   after  the  record  date  for  the
determination  of  stockholders  entitled  to receive  such  rights,  options or
warrants.
                  (c)  In  case  the  Company   shall   distribute   to  all  or
substantially  all  holders  of its  shares of  Common  Stock  evidences  of its
indebtedness or assets (excluding cash dividends or distributions payable out of
consolidated earnings or earned surplus and dividends or distributions  referred
to in paragraph (a) above) or rights, options or warrants, or convertible or

                                       -6-

<PAGE>



exchangeable securities containing the right to subscribe for or purchase shares
of Common Stock  (excluding  those referred to in paragraph (b) above),  then in
each case the number of shares thereafter  purchasable upon the exercise of this
option  shall be  determined  by  multiplying  the number of shares  theretofore
purchasable  upon the  exercise  of this  option  by a  fraction,  of which  the
numerator  shall be the then current  market price per share of Common Stock (as
defined in paragraph (d) below) on the date of such  distribution,  and of which
the  denominator  shall be the then  current  market  price  per share of Common
Stock,  less the then fair  value (as  determined  in good faith by the Board of
Directors of the Company, or if requested by the Optionee,  by a leading firm of
investment  bankers  selected by the Optionee and  reasonably  acceptable to the
Company and whose  reasonable  fees and expenses shall be paid by the Company or
as otherwise agreed upon by the Company and the Optionee), of the portion of the
assets or evidences  of  indebtedness  so  distributed  or of such  subscription
rights, options or warrants, or of such convertible or exchangeable  securities,
applicable to one share of Common Stock.  Such adjustment shall be made whenever
any such  distribution  is  made,  and  shall  become  effective  on the date of
distribution   retroactive  to  the  record  date  for  the   determination   of
shareholders entitled to receive such distribution.
                  (d) For the purpose of  computation  under  paragraphs (b) and
(c) of this paragraph H.1, the current market price per share of Common Stock at
any date shall be:

                                       -7-

<PAGE>



                           (x) from and after 30 trading days after consummation
                  of a  Qualifying  Offering  (as such  term is  defined  in the
                  Company's  Certificate  of  Incorporation,  as  amended),  the
                  average of the daily  closing  prices  for the 30  consecutive
                  trading  days  immediately  preceding  such  computation.  The
                  closing  price for each day shall be the last  reported  sales
                  price  regular  way or, in case no such  reported  sale  takes
                  place on such day,  the  average of the  closing bid and asked
                  prices regular way for such day, in each case on the principal
                  national  securities  exchange  on which the  shares of Common
                  Stock are listed or admitted  to  trading,  or, if reported on
                  NASDAQ-National  Market System, the last reported sales price,
                  or, if not so listed or admitted to trading or  reported,  the
                  average  of the  closing  bid and asked  prices of the  Common
                  Stock in the over-the-counter  market as reported by NASDAQ or
                  any comparable system; and
                           (y) on or prior to the  expiration  of the 30 trading
                  day  period set forth in clause  (x)  above,  the fair  market
                  value per share of Common Stock  determined  by a leading firm
                  of investment  bankers selected by the Optionee and reasonably
                  acceptable  to the  Company  and  whose  reasonable  fees  and
                  expenses  shall be paid by the Company.
                           (e) No  adjustment in the number of shares
purchasable hereunder shall be required unless such adjustment  would require an
increase or decrease of at least one percent (1%) in the number of 

                                       -8-

<PAGE>



shares purchasable upon the exercise of this option; provided, however, that any
adjustments  which by reason of this  paragraph  (e) are not required to be made
shall be carried  forward and taken into account in any  subsequent  adjustment.
All calculations shall be made to the nearest one-thousandth of a share.
                  (f)  Whenever  the  number  of  shares  purchasable  upon  the
exercise of this option is adjusted,  as herein  provided,  the  Exercise  Price
payable upon the exercise of this option shall be adjusted by  multiplying  such
Exercise Price immediately prior to such adjustment by a fraction,  of which the
numerator  shall be the number of shares  purchasable  upon the exercise of this
option immediately prior to such adjustment,  and of which the denominator shall
be the number of shares purchasable immediately thereafter.
                  (g) No adjustment in the number of shares purchasable upon the
exercise of this option need be made under paragraphs (b) and (c) if the Company
issues  or  distributes  to the  Optionee  the  rights,  options,  warrants,  or
convertible or exchangeable  securities,  or evidences of indebtedness or assets
referred to in those  paragraphs  which the Optionee would have been entitled to
receive had the option been  exercised  prior to the  happening of such event or
the record date with  respect  thereto.  No  adjustment  in the number of shares
purchasable  upon the  exercise  of this  option  may be made for sale of shares
pursuant  to a Company  plan for  reinvestment  of  dividends  or  interest.  No
adjustment need be made for a change in the par value of the shares.

                                       -9-

<PAGE>



                  (h) The Company shall not, by amendment of its  Certificate of
Incorporation  or through  any  reorganization,  recapitalization,  transfer  of
assets, consolidation, merger, dissolution, issue or sale of securities, rights,
options or warrants or any other  voluntary  action,  avoid or seek to avoid the
observance or performance of any of the terms to be observed or performed  under
this paragraph H.1 by the Company, but will at all times in good faith assist in
carrying out all of the  provisions  of this  paragraph H.1 and in the taking of
such actions as may be necessary or  appropriate  in order to protect the rights
of the Optionee under this paragraph H.1 against impairment.
                  (i) For the purpose of this paragraph H.1, the term "shares of
Common  Stock" shall mean (i) the class of stock  designated as the common stock
of the Company at the date of this Certificate, or (ii) any other class of stock
resulting from successive changes or  reclassification of such shares consisting
solely of changes in par value,  or from par value to no par value. In the event
that at any time,  as a result of an  adjustment  made pursuant to paragraph (a)
above,  the Optionee  shall become  entitled to purchase any  securities  of the
Company other than shares of Common Stock,  thereafter  the number of such other
shares so  purchasable  upon exercise of this option,  and the Exercise Price of
such shares, shall be subject to adjustment from time to time in a manner and on
terms as nearly  equivalent as practicable to the provisions with respect to the
shares  contained in  paragraphs  (a) through  (h),  inclusive,  above,  and the
paragraphs H.2 through H.4,

                                      -10-

<PAGE>



inclusive,  with  respect to the  shares,  shall apply on like terms to any such
other securities.
                  (j) Upon the  expiration of any rights,  options,  warrants or
conversion or exchange privileges, if any thereof shall not have been exercised,
the Exercise  Price and the number of shares  shall,  upon such  expiration,  be
readjusted  and  shall  thereafter  be such as it  would  have  been had it been
originally  adjusted (or had the original  adjustment not been required,  as the
case may be),  as if (A) the only  shares  of Common  Stock so  issued  were the
shares of Common  Stock,  if any,  actually  issued or sold upon the exercise of
such rights,  options,  warrants or conversion  or exchange  rights and (B) such
shares of  Common  Stock,  if any,  were  issued  or sold for the  consideration
actually  received  by  the  Company  upon  such  exercise  plus  the  aggregate
consideration,  if any, actually received by the Company for the issuance,  sale
or grant of all such rights, options,  warrants or conversion or exchange rights
whether or not exercised;  provided,  further,  that no such readjustment  shall
have the effect of increasing  the Exercise  Price or  decreasing  the number of
shares by an amount in excess of the amount of the adjustment  initially made in
respect to the  issuance,  sale or grant of such  rights,  options,  warrants or
conversion or exchange rights.
                  H.2.     Notice of Adjustment.  Whenever the number of shares
or the Exercise Price payable upon exercise of this option is
adjusted, as herein provided, the Company shall promptly mail by
first class, postage prepaid, to the Optionee, notice of such

                                      -11-

<PAGE>



adjustment or  adjustments  and a certificate  of a firm of  independent  public
accountants  selected by the Board of  Directors  of the Company (who may be the
regular accountants  employed by the Company) setting forth the number of shares
and the  Exercise  Price  payable  upon  exercise  of  this  option  after  such
adjustment,  setting  forth  a  brief  statement  of the  facts  requiring  such
adjustment and setting forth the computation by which such adjustment was made.
                  H.3.     No Adjustment for Dividends.  Except as provided in
paragraph H.1, no adjustment in respect of any dividends shall be made during 
the term of this option or upon the exercise of this option.
                  H.4.    Preservation   of   Purchase   Rights   Upon   Merger,
Consolidation,  etc. In case of any  consolidation of the Company with or merger
of the Company  into  another  corporation  or otherwise or in case of any sale,
transfer  or  lease  to  another  corporation  of all or  substantially  all the
property  of  the  Company,   the  Company  or  such   successor  or  purchasing
corporation,  as the case may be,  shall  execute with the Optionee an agreement
that the Optionee shall have the right  thereafter  upon payment of the Exercise
Price in effect  immediately  prior to such action to purchase  upon exercise of
this  option  the kind and amount of shares and other  securities  and  property
which such holder  would have owned or have been  entitled to receive  after the
happening of such consolidation, merger, sale, transfer or lease had this option
been exercised  immediately  prior to such action,  provided that such agreement
shall provide for adjustments thereafter, which shall be as nearly

                                      -12-

<PAGE>



equivalent  as may  be  practicable  to the  adjustments  provided  for in  this
paragraph  H.  The  provisions  of this  paragraph  H shall  similarly  apply to
successive consolidations, mergers, sales, transfers or leases.
         I.  Registration Rights.  Optionee shall have the registration rights
with respect to this option as set forth in the Amended and Restated
Registration Rights Agreement dated as of June 30, 1995 and entered into by and
among the Company, the Optionee and the other executive officers of the Company
set forth therein.

                                          AMERICAN COMMUNICATIONS SERVICES, INC.


                                          By: /s/ RICHARD A. KOZAK
                                          Richard A. Kozak
                                          President and Chief Operating
                                               Officer


Dated as of:  As of June 30, 1995





ATTEST:    /s/ RILEY M. MURPHY,
           Riley M. Murphy, Secretary

                                      -13-

<PAGE>



                                  PURCHASE FORM


                                                                 Date: _________



         TO:  Chief Financial Officer

         The  undersigned  hereby  irrevocably  elects to exercise  the attached
         Non-Qualified  Stock  Option  Certificate  to the  extent of options to
         purchase  _______  shares and hereby makes payment of $_____ in payment
         of the purchase price thereof.

                  INSTRUCTIONS FOR REGISTRATION OF SECURITIES

                  Name:____________________________________

                  Address:_________________________________
                          ---------------------------------



                                                           ---------------------

                                      -14-

<PAGE>



                     AMERICAN COMMUNICATIONS SERVICES, INC.
                     NON-QUALIFIED STOCK OPTION CERTIFICATE


                  A. A STOCK  OPTION  for the  purchase  of a total  of  350,000
shares of the common stock,  par value $0.01 (the "Common  Stock"),  of American
Communications  Services,  Inc. (the  "Company")  has been granted to Anthony J.
Pompliano  (the  "Optionee"),  pursuant  to  subparagraph  5(c)(iii)  of a Third
Amended and Restated Employment  Agreement dated as of June 30, 1995 between the
Optionee  and the Company  (the  "Employment  Agreement").  This option shall be
governed by the Employment  Agreement and, except as otherwise  specifically set
forth herein,  the provisions of the Employment  Agreement  shall control in the
event of any conflict  between the terms set forth herein and the  provisions of
the  Employment  Agreement.  Unless  otherwise  defined  herein,  all  initially
capitalized  terms used herein  shall have the same  meaning as set forth in the
Employment Agreement.
                  B. The per share exercise price of this option is as set forth
below in paragraph E (the "Exercise Price"). 
                  C. This option may not be  exercised if the issuance of shares
of Common Stock of the Company upon such exercise  would  constitute a violation
of any applicable  Federal or state  securities or other law or regulation.  The
Optionee,  as a condition to his exercise of this option, shall (i) represent to
the Company that the shares of Common Stock of the Company that he acquires upon
exercise of this option are being  acquired by him for investment and not with a
view to distribution or resale, and that

                                       -1-

<PAGE>



he will not sell or otherwise  transfer  such shares unless such shares are then
registered  under  a  currently  effective   registration  statement  under  the
Securities  Act of 1933,  as amended (the "Act"),  or counsel for the Company is
then of the opinion that such  registration is not required under the Act or any
other applicable law, regulation, or rule of any governmental agency and (ii) if
the shares of Common Stock  underlying this option are not registered  under the
Act, acknowledge that the certificate evidencing such shares may be stamped with
a restrictive legend and such shares will be "restricted  securities" as defined
in Rule 144 promulgated under the Act.
                  D. This option may not be transferred in any manner  otherwise
than by will or the  laws of  descent  and  distribution,  and may be  exercised
during the  lifetime of the  Optionee  only by the  Optionee.  The terms of this
option shall be binding upon the executors,  administrators,  heirs, successors,
and assigns of the Optionee.
                  E. This  option  shall vest and become  exercisable  as to all
shares set forth below (each group of shares set forth below  referred to herein
as a  "tranche")  on August 24, 2001 if  Optionee  shall then be employed by the
Company;  provided,  however, that this option immediately shall vest and become
exercisable  provided  that  Optionee is then  employed by the Company (i) as to
each tranche of shares upon the occurrence of the events  described  below;  and
(ii) as to all of the tranches of shares upon a Change in Control,  whichever is
the first to occur. This option shall be exercisable

                                       -2-

<PAGE>



at the per share exercise price set forth below, and to the extent not exercised
shall  terminate  and be of no further  effect with  respect to each  tranche of
shares as of 5:00 p.m.  New York City time five (5) years from the date on which
the option first became exercisable as to such tranche of shares.


<TABLE>
<CAPTION>

Number of Shares         Event                                                            Per Share Exercise Price
----------------         -----                                                            ------------------------

<C>                      <C>                                                                        <C>   
100,000                  Prior to June 30, 1996 the Company executes an effective                   $ 2.25
                         agreement with a major strategic partner/investor as approved
                         by the Board of Directors.

125,000                  Such options shall vest upon the attainment of certain                     $ 2.80
                         performance goals determined by the compensation committee
                         of the board of directors relating to the Company's annual
                         plan approved by the board of directors for the fiscal year
                         ending June 30 ("Fiscal 1997"), 1997, such as the level of
                         appreciation of the publicly-traded price (as defined in
                         paragraph 5(h) of the Employment Agreement) of the Common
                         Stock during Fiscal 1997 and the consummation of strategic
                         business combinations, and other performance goals deemed
                         important by the compensation committee.  The performance
                         goals for Fiscal 1997 shall be determined by the compensation
                         committee no later than June 30, 1996.

125,000                  Such options shall vest upon the attainment of certain                     $ 2.80
                         performance goals determined by the compensation committee
                         of the board of directors relating to the Company's annual
                         plan approved by the board of directors for the fiscal year
                         ending June 30, 1998 (Fiscal 1998), such as the level of
                         appreciation of the publicly-traded price (as defined in
                         paragrpah 5(h) of the Employment Agreement) of the Common
                         Stock during Fiscal 1998 and the consummation of strategic
                         business combinations, and other performance goals deemed
                         important by the compensation committee.  The performance
                         goals for fiscal 1998 shall be determined by the compensation
                         committee no later than June 30, 1997. 
               

                                       -3-
</TABLE>

<PAGE>



                  F. Notwithstanding the foregoing, this option shall not become
exercisable  as to a tranche  of  shares  if  Optionee  voluntarily  leaves  the
Company's employ or if Optionee is terminated For Cause (as defined in paragraph
11 of the Employment Agreement) prior to the date the option becomes exercisable
as to such shares as set forth in paragraph E hereof.
                  G. Subject to the provisions of paragraphs E and F, the rights
represented by this option may be exercised by the Optionee by delivery of:
                  a. the exercise form annexed hereto (the "Exercise Form") duly
executed and specifying the number of shares to be purchased,  to the Company at
the offices of the Company located at 131 National Business Parkway,  Suite 100,
Annapolis  Junction,  Maryland  20701  (or such  other  office  or agency of the
Company as it may  designate  by notice to the  Optionee  at the address of such
Optionee  appearing on the books of the Company) during normal business hours on
any day  other  than a  Saturday,  Sunday  or day on which  national  banks  are
authorized  to  close in the City of New  York,  State of New York (a  "Business
Day").
                  b. Payment to the Company,  for the account of the Company, by
cash or by certified or bank cashier's  check or wire transfer,  of the Exercise
Price for the number of shares specified in the Exercise Form in lawful money of
the United States of America.
                  The  Company  agrees  that such  shares  shall be deemed to be
issued to the Optionee as the record owner of such shares as of the

                                       -4-

<PAGE>



commencement  of  business  on the date on which  this  option  shall  have been
surrendered and payment made for the shares as aforesaid.  Certificates  for the
shares  specified  in the  Exercise  Form shall be  delivered to the Optionee as
promptly as practicable,  and in any event within ten (10) days  thereafter.  If
this option shall have been exercised  only in part,  the Company shall,  at the
time of delivery of the certificate or  certificates  delivered to the Optionee,
deliver a new option  evidencing  the right to  purchase  the  remaining  shares
issuable  under this  option,  which new option  shall in all other  respects be
identical  to this option.  No  adjustment  shall be made on shares  issuable on
exercise  of this  option for any cash  dividends  paid or payable to holders of
record of Common Stock out of  consolidated  earnings or earned surplus prior to
the date as of which the  Optionee  shall be deemed to be the  record-holder  of
such shares.
                  H.       Certain Adjustments.
                           --------------------

                  H.1.  The number of shares  purchasable  upon the  exercise of
this option and the Exercise Price shall be subject to adjustment as follows:
                  (a) In case the Company  shall (i) pay a dividend in shares of
Common Stock or make a  distribution  in shares of Common Stock,  (ii) subdivide
its outstanding shares of Common Stock (including, without limitation, by way of
stock splits and the like), (iii) combine its outstanding shares of Common Stock
into  a  smaller   number  of   shares  of  Common   Stock  or  (iv)   issue  by
reclassification of its shares of Common Stock other securities of

                                       -5-

<PAGE>



the  Company  (including  any  such   reclassification   in  connection  with  a
consolidation or merger in which the Company is the surviving corporation),  the
number of shares  purchasable  upon  exercise of this option  immediately  prior
thereto shall be adjusted so that the Optionee  shall be entitled to receive the
kind and number of shares or other securities of the Company which he would have
owned or have been  entitled to receive after the happening of any of the events
described  above  had  this  option  been  exercised  immediately  prior  to the
happening of such event or any record date with respect  thereto.  An adjustment
made pursuant to this paragraph (a) shall become effective immediately after the
effective  date of each such event  retroactive  to the record date, if any, for
such event, without amendment or modification required to this document.
                  (b) In  case  the  Company  shall  issue  rights,  options  or
warrants to all or  substantially  all holders of its outstanding  Common Stock,
without any charge to such holders,  entitling them to subscribe for or purchase
shares of Common  Stock at a price per share  which is lower at the record  date
mentioned below than the then current market price per share of Common Stock (as
defined in paragraph  (d) below),  the number of shares  thereafter  purchasable
upon the exercise of this option shall be determined by  multiplying  the number
of shares theretofore purchasable upon exercise of this option by a fraction, of
which the numerator shall be the number of shares of Common Stock outstanding on
the date of issuance  of such  rights,  options or  warrants  plus the number of
additional  shares of Common Stock offered for subscription or purchase,  and of
which the

                                       -6-

<PAGE>



denominator  shall be the number of shares of Common  Stock  outstanding  on the
date of issuance of such rights,  options or warrants  plus the number of shares
which the aggregate offering price of the total number of shares of Common Stock
so offered would  purchase at the current market price per share of Common Stock
at such record date. Such adjustment shall be made whenever such rights, options
or warrants are issued, and shall become effective  immediately after the record
date for the  determination  of  stockholders  entitled to receive  such rights,
options or warrants.
                  (c)  In  case  the  Company   shall   distribute   to  all  or
substantially  all  holders  of its  shares of  Common  Stock  evidences  of its
indebtedness or assets (excluding cash dividends or distributions payable out of
consolidated earnings or earned surplus and dividends or distributions  referred
to in paragraph (a) above) or rights,  options or warrants,  or  convertible  or
exchangeable securities containing the right to subscribe for or purchase shares
of Common Stock  (excluding  those referred to in paragraph (b) above),  then in
each case the number of shares thereafter  purchasable upon the exercise of this
option  shall be  determined  by  multiplying  the number of shares  theretofore
purchasable  upon the  exercise  of this  option  by a  fraction,  of which  the
numerator  shall be the then current  market price per share of Common Stock (as
defined in paragraph (d) below) on the date of such  distribution,  and of which
the  denominator  shall be the then  current  market  price  per share of Common
Stock, less the

                                       -7-

<PAGE>



then fair value (as  determined  in good faith by the Board of  Directors of the
Company,  or if  requested  by the  Optionee,  by a leading  firm of  investment
bankers  selected by the Optionee and  reasonably  acceptable to the Company and
whose  reasonable fees and expenses shall be paid by the Company or as otherwise
agreed upon by the Company  and the  Optionee),  of the portion of the assets or
evidences of indebtedness so distributed or of such subscription rights, options
or warrants,  or of such convertible or exchangeable  securities,  applicable to
one share of Common  Stock.  Such  adjustment  shall be made  whenever  any such
distribution  is made,  and shall become  effective on the date of  distribution
retroactive to the record date for the determination of shareholders entitled to
receive such distribution.
                  (d) For the purpose of  computation  under  paragraphs (b) and
(c) of this paragraph H.1, the current market price per share of Common Stock at
any date shall be:
                           (x) from and after 30 trading days after consummation
                  of a  Qualifying  Offering  (as such  term is  defined  in the
                  Company's  Certificate  of  Incorporation,  as  amended),  the
                  average of the daily  closing  prices  for the 30  consecutive
                  trading  days  immediately  preceding  such  computation.  The
                  closing  price for each day shall be the last  reported  sales
                  price  regular  way or, in case no such  reported  sale  takes
                  place on such day,  the  average of the  closing bid and asked
                  prices regular way for such day, in each case on the principal
                  national securities exchange

                                       -8-

<PAGE>



                  on which the shares of Common  Stock are listed or admitted to
                  trading, or, if reported on NASDAQ-National Market System, the
                  last reported sales price, or, if not so listed or admitted to
                  trading or reported,  the average of the closing bid and asked
                  prices of the Common Stock in the  over-the-counter  market as
                  reported by NASDAQ or any comparable system; and
                           (y) on or prior to the  expiration  of the 30 trading
                  day  period set forth in clause  (x)  above,  the fair  market
                  value per share of Common Stock  determined  by a leading firm
                  of investment  bankers selected by the Optionee and reasonably
                  acceptable  to the  Company  and  whose  reasonable  fees  and
                  expenses  shall be paid by the Company.  (e) No  adjustment in
                  the number of shares purchasable
hereunder shall be required unless such adjustment  would require an increase or
decrease of at least one percent (1%) in the number of shares  purchasable  upon
the exercise of this option;  provided,  however,  that any adjustments which by
reason  of this  paragraph  (e) are not  required  to be made  shall be  carried
forward and taken into account in any subsequent  adjustment.  All  calculations
shall be made to the nearest one-thousandth of a share.
                  (f)  Whenever  the  number  of  shares  purchasable  upon  the
exercise of this option is adjusted,  as herein  provided,  the  Exercise  Price
payable upon the exercise of this option shall be adjusted by  multiplying  such
Exercise Price immediately prior to such adjustment by a fraction,  of which the
numerator shall be the

                                       -9-

<PAGE>



number of shares  purchasable upon the exercise of this option immediately prior
to such adjustment,  and of which the denominator  shall be the number of shares
purchasable immediately thereafter.
                  (g) No adjustment in the number of shares purchasable upon the
exercise of this option need be made under paragraphs (b) and (c) if the Company
issues  or  distributes  to the  Optionee  the  rights,  options,  warrants,  or
convertible or exchangeable  securities,  or evidences of indebtedness or assets
referred to in those  paragraphs  which the Optionee would have been entitled to
receive had the option been  exercised  prior to the  happening of such event or
the record date with  respect  thereto.  No  adjustment  in the number of shares
purchasable  upon the  exercise  of this  option  may be made for sale of shares
pursuant  to a Company  plan for  reinvestment  of  dividends  or  interest.  No
adjustment need be made for a change in the par value of the shares.
                  (h) The Company shall not, by amendment of its  Certificate of
Incorporation  or through  any  reorganization,  recapitalization,  transfer  of
assets, consolidation, merger, dissolution, issue or sale of securities, rights,
options or warrants or any other  voluntary  action,  avoid or seek to avoid the
observance or performance of any of the terms to be observed or performed  under
this paragraph H.1 by the Company, but will at all times in good faith assist in
carrying out all of the  provisions  of this  paragraph H.1 and in the taking of
such actions as may be necessary or  appropriate  in order to protect the rights
of the Optionee under this paragraph H.1 against impairment.

                                      -10-

<PAGE>



                  (i) For the purpose of this paragraph H.1, the term "shares of
Common  Stock" shall mean (i) the class of stock  designated as the common stock
of the Company at the date of this Certificate, or (ii) any other class of stock
resulting from successive changes or  reclassification of such shares consisting
solely of changes in par value,  or from par value to no par value. In the event
that at any time,  as a result of an  adjustment  made pursuant to paragraph (a)
above,  the Optionee  shall become  entitled to purchase any  securities  of the
Company other than shares of Common Stock,  thereafter  the number of such other
shares so  purchasable  upon exercise of this option,  and the Exercise Price of
such shares, shall be subject to adjustment from time to time in a manner and on
terms as nearly  equivalent as practicable to the provisions with respect to the
shares  contained in  paragraphs  (a) through  (h),  inclusive,  above,  and the
paragraphs H.2 through H.4, inclusive,  with respect to the shares,  shall apply
on like terms to any such other securities.
                  (j) Upon the  expiration of any rights,  options,  warrants or
conversion or exchange privileges, if any thereof shall not have been exercised,
the Exercise  Price and the number of shares  shall,  upon such  expiration,  be
readjusted  and  shall  thereafter  be such as it  would  have  been had it been
originally  adjusted (or had the original  adjustment not been required,  as the
case may be),  as if (A) the only  shares  of Common  Stock so  issued  were the
shares of Common  Stock,  if any,  actually  issued or sold upon the exercise of
such rights, options, warrants or conversion or exchange rights and

                                      -11-

<PAGE>



(B)  such  shares  of  Common  Stock,  if  any,  were  issued  or  sold  for the
consideration  actually  received by the  Company  upon such  exercise  plus the
aggregate  consideration,  if any,  actually  received  by the  Company  for the
issuance, sale or grant of all such rights,  options,  warrants or conversion or
exchange  rights  whether  or not  exercised;  provided,  further,  that no such
readjustment  shall  have  the  effect  of  increasing  the  Exercise  Price  or
decreasing  the  number of  shares  by an amount in excess of the  amount of the
adjustment  initially  made in  respect to the  issuance,  sale or grant of such
rights, options, warrants or conversion or exchange rights.

                  H.2.  Notice of Adjustment.  Whenever the number of shares or
the Exercise  Price payable upon exercise of this option is adjusted,  as herein
provided,  the Company shall promptly mail by first class,  postage prepaid,  to
the Optionee,  notice of such  adjustment or adjustments  and a certificate of a
firm of independent public accountants selected by the Board of Directors of the
Company (who may be the regular  accountants  employed by the  Company)  setting
forth the number of shares and the Exercise  Price payable upon exercise of this
option  after such  adjustment,  setting  forth a brief  statement  of the facts
requiring  such  adjustment  and  setting  forth the  computation  by which such
adjustment was made.
                  H.3.  No Adjustment for Dividends.  Except as provided in
paragraph H.1, no adjustment in respect of any dividends shall be
made during the term of this option or upon the exercise of this
option.

                                      -12-

<PAGE>



                  H.4.  Preservation   of   Purchase   Rights   Upon   Merger,
Consolidation,  etc. In case of any  consolidation of the Company with or merger
of the Company  into  another  corporation  or otherwise or in case of any sale,
transfer  or  lease  to  another  corporation  of all or  substantially  all the
property  of  the  Company,   the  Company  or  such   successor  or  purchasing
corporation,  as the case may be,  shall  execute with the Optionee an agreement
that the Optionee shall have the right  thereafter  upon payment of the Exercise
Price in effect  immediately  prior to such action to purchase  upon exercise of
this  option  the kind and amount of shares and other  securities  and  property
which such holder  would have owned or have been  entitled to receive  after the
happening of such consolidation, merger, sale, transfer or lease had this option
been exercised  immediately  prior to such action,  provided that such agreement
shall provide for adjustments thereafter, which shall be as nearly equivalent as
may be  practicable  to the  adjustments  provided for in this  paragraph H. The
provisions   of  this   paragraph  H  shall   similarly   apply  to   successive
consolidations, mergers, sales, transfers or leases.

                                      -13-

<PAGE>



         I.  Registration Rights.  Optionee shall have the registration rights
with respect to this option as set forth in the Amended and Restated
Registration Rights Agreement dated as of June 30, 1995 and entered into by and
among the Company, the Optionee and the other executive officers of the Company
set forth therein.


                                          AMERICAN COMMUNICATIONS SERVICES, INC.


                                          By: /s/ RICHARD A. KOZAK
                                          Richard A. Kozak
                                          President and Chief Operating
                                               Officer


Dated as of:  As of June 30, 1995


ATTEST:   /s/ RILEY M. MURPHY,
          Riley M. Murphy, Secretary

                                      -14-

<PAGE>



                                  PURCHASE FORM


                                                                 Date: _________



         TO:  Chief Financial Officer

         The  undersigned  hereby  irrevocably  elects to exercise  the attached
         Non-Qualified  Stock  Option  Certificate  to the  extent of options to
         purchase  _______  shares and hereby makes payment of $_____ in payment
         of the purchase price thereof.

                  INSTRUCTIONS FOR REGISTRATION OF SECURITIES

                  Name:____________________________________

                  Address:_________________________________
                          ---------------------------------



                                                           ---------------------

                                      -15-