EXHIBIT 10.21

                    AGREEMENT OF REFORMATION AND AMENDMENT


      THIS AGREEMENT OF REFORMATION AND AMENDMENT (the "Agreement") is made as
of the 31st day of March, 1998 (the "Agreement Date"), by and among Michael C.
Higgins  and  Michael  S.  Cannon   (collectively,   the  "Stockholders"  and,
individually,  a "Stockholder") and ZMAX Corporation,  a Delaware  corporation
("ZMAX").

                                   RECITALS

      A.    The  Stockholders  formerly  owned all the  outstanding  shares of
Century  Services,  Inc., a Maryland  corporation  ("CSI") having  proprietary
rights in and ownership of specialized  computer software and a workforce with
specialized  skills  relating to the  correction of the Year 2000 problem.  On
November 6, 1996 (the "Original  Effective  Date"),  the Stockholders  entered
into a Stock Purchase Agreement (the "Acquisition Agreement") with ZMAX, which
at that time was a public  company with no  operations,  whereby ZMAX acquired
all of the  issued  and  outstanding  shares of CSI from the  Stockholders  in
exchange for the issuance by ZMAX to the  Stockholders of 3,200,000  shares of
ZMAX common stock,  par value $.001 per share ("ZMAX Stock").  On the Original
Effective Date, all of the 3,200,000 shares of ZMAX Stock were recorded in the
names of the Stockholders,  with 1,600,000 shares of ZMAX Stock being recorded
in the name of each Stockholder,  and with the Stockholders  having all voting
rights and dividend and  distribution  rights  (including the right to receive
liquidating distributions) with respect to all 3,200,000 shares of ZMAX Stock.

      B.    In order to  incentivize  the  Stockholders,  both of whom  became
senior members of the management of ZMAX after the Original Effective Date and
one of whom  became a member  of the  Board of  Directors  of ZMAX  after  the
Original Effective Date, to increase the cash flow of ZMAX, the parties agreed
that  2,800,000  shares (the  "Restricted  Stock") of ZMAX Stock issued to the
Stockholders under the Acquisition  Agreement would be subject to restrictions
on transferability  as contained in Section 1.5 of the Acquisition  Agreement.
Under the terms of the Acquisition  Agreement,  the shares of Restricted Stock
were  deposited  into  escrow  with  Powell,  Goldstein,  Frazer & Murphy (the
"Escrow  Agent"),  pursuant to an Earn Out Stock  Escrow  Agreement  dated the
Original Effective Date (the "Escrow  Agreement") among ZMAX, the Escrow Agent
and the Stockholders. The Acquisition Agreement provides that one (1) share of
Restricted   Stock  will  be  released  from  escrow  and  delivered  to  each
Stockholder  for every  $1.25 of Cash Flow (as  defined in Section  1.5 of the
Acquisition  Agreement)  generated by CSI. The  Acquisition  Agreement and the
Escrow  Agreement  contain  additional  restrictions  on  the  release  of the
Restricted Shares from escrow; however,  neither the Acquisition Agreement nor
the Escrow Agreement provides a definite term for which the release provisions
will apply to the Restricted Stock. Even after the Restricted Stock was placed
into escrow, the Stockholders  continue to have all voting rights and dividend
and  distribution   rights   (including  the  right  to  receive   liquidating
distributions) on the Restricted Stock.


<PAGE>

      C.    In connection with the execution of the Acquisition Agreement, the
parties  entered into the following  additional  agreements as of the Original
Effective Date: (1) the Stockholders Agreement (the "Stockholders Agreement"),
pursuant  to  which  all  3,200,000  shares  of the  ZMAX  Stock  owned by the
Stockholders (including the Restricted Stock) remain subject to various rights
and  restrictions  (described in Recital D below);  (2) a Compensation  Escrow
Agreement with the Bank of Alexandria,  which is no longer in effect as of the
date hereof;  (3) an Employment  Agreement  between  Michael Higgins and ZMAX,
which  remains  in  effect  as of the date  hereof  (the  "Higgins  Employment
Agreement"),  and an Employment  Agreement  between  Michael  Cannon and ZMAX,
which is no longer in effect as of the date  hereof  (the  "Cannon  Employment
Agreement")(with  the Higgins  Employment  Agreement and the Cannon Employment
Agreement being collectively referred to as the "Employment Agreements");  and
(4) Stock Pledge and Security Agreements,  which are no longer in effect as of
the date hereof.

      D.    The Stockholders  Agreement has a term of three years and provides
that  neither  Stockholder  may sell,  pledge,  encumber,  give,  bequeath  or
otherwise  transfer  or dispose of any  shares of ZMAX  Stock  (including  the
Restricted Stock) during such three-year term without first complying with the
terms and  conditions of the  Stockholders  Agreement or receiving the advance
written  consent of ZMAX.  On June 17, 1997,  the  Stockholders  Agreement was
amended  by the  parties  to give  ZMAX a right  of  repurchase  (in lieu of a
mandatory  obligation to purchase) a Stockholder's shares of ZMAX Stock at the
Current Value Price of such shares in the event of a Stockholder's  death. The
Stockholders Agreement,  as amended,  provides that in the event a Stockholder
is terminated from employment  (with or without  cause),  becomes  permanently
disabled,  breaches the  non-competition  or non-disclosure  provisions of his
Employment  Agreement  or dies,  ZMAX  generally  has the  right  (but not the
obligation) to purchase all or a portion of the  Stockholder's  shares of ZMAX
Stock at the Current Value Price (as defined in Section 8 of the  Stockholders
Agreement).  The restrictions on the  transferability  of the Restricted Stock
remain in effect after a Stockholder's  termination  from  employment  without
cause,  or in the event of disability or death. If a Stockholder is terminated
with cause from employment  with ZMAX, his rights in any remaining  Restricted
Stock are forfeited and such shares are to be returned to ZMAX.

      E.    On April 22, 1997 (the "Separation Date"), Michael Cannon and ZMAX
entered into a Separation Agreement (the "Separation Agreement"),  pursuant to
which Mr. Cannon was terminated from employment under his Employment Agreement
without cause. In  consideration  for the early  termination of his Employment
Agreement,  ZMAX agreed to pay severance  payments to Mr. Cannon in the amount
of $100,000 per annum  through  November 6, 1999,  being the date on which his
Employment  Agreement was to expire. In addition,  Mr. Cannon agreed to resign
as an officer of ZMAX and to have the  transfer  restrictions  relating to the
Restricted  Stock  contained  in the  Acquisition  Agreement  and  the  Escrow
Agreement  continue to apply,  even though Mr. Cannon was no longer an officer
of ZMAX.  Beginning on the Separation  Date and  continuing  until November 6,
1999,  Mr.  Cannon  was to serve  as a  consultant  to ZMAX for no  additional
compensation,  pursuant to a Consulting  Agreement  dated as of the Separation
Date  (the  "Consulting  Agreement").  Mr.  Cannon  also  agreed  to have  the
non-competition,   non-  solicitation  and  non-disclosure  covenants  of  his
Employment Agreement continue for the time periods set forth in the Employment
Agreement.


                                      2

<PAGE>

      F.    In the  acquisition by ZMAX of all the  outstanding  shares of CSI
from the Stockholders, the original intent of the parties was that ZMAX issued
3,200,000  shares  of ZMAX  Stock  (including  the  Restricted  Stock)  to the
Stockholders  in  consideration  for their  shares of CSI stock.  The  parties
further intended that the Stockholders were to have all rights of ownership in
the 3,200,000 shares of ZMAX Stock (including the Restricted  Stock),  subject
only to restrictions on  transferability  of the Restricted Stock that were to
be tied to the cash flow  performance  requirements  of ZMAX as  contained  in
Section 1.5 of the Acquisition  Agreement.  After further review,  the parties
believe that the combination of such cash flow  performance  requirements  and
the transfer restrictions imposed under the Escrow Agreement have the mistaken
and  unintended  effect of requiring the  Stockholders  to earn the Restricted
Shares  twice,  once upon the  original  issuance of the shares by ZMAX in its
acquisition  of CSI from the  Stockholders  and a second  time  following  the
satisfaction of the cash flow requirements.  To correct this mutual mistake of
material fact, the parties now desire to cause the Escrow Agent to release the
Restricted  Stock  from  escrow,  subject  to the  continuation  of  the  same
restrictions on  transferability of the Restricted Stock which presently exist
under the various  agreements  between the parties.  The parties therefore now
desire to reform the  existing  agreements  between  the parties in the manner
hereinafter provided to correct such mutual mistake of material fact.


      NOW,  THEREFORE,  in  consideration of the mutual covenants and premises
contained  herein,  the parties  hereto  intending to be legally bound and for
good and adequate  consideration,  the  sufficiency of which is  acknowledged,
agree to reform and amend the aforementioned agreements as follows:


      1.    INCORPORATION BY REFERENCE.  The foregoing Recital  paragraphs are
hereby incorporated in their entirety into this Agreement.

      2.    REFERENCES TO EARN OUT STOCK.  All  references to "Earn Out Stock"
contained in the  Stockholders  Agreement,  the Acquisition  Agreement and any
other agreement executed as of the Original Effective Date shall be changed to
"Restricted Stock," as that term is defined in the Recital paragraphs above.

      3.    REFORMATION  AND  AMENDMENT  OF  THE  ACQUISITION  AGREEMENT.  The
parties  hereby agree that the  Acquisition  Agreement is hereby  reformed and
amended  retroactive as of the Original  Effective Date as provided  below, so
that the  Restricted  Stock is no  longer  held in  escrow  under  the  Escrow
Agreement, but nevertheless the restrictions on transferability continue to be
in effect, subject only to the cash flow performance requirements contained in
Section 1.5 of the Acquisition  Agreement.  The parties further agree that the
Stockholders Agreement is reformed and amended as provided below to include in
the Stockholders  Agreement the cash flow performance  requirements  presently
contained  in the  Acquisition  Agreement,  with such  cash  flow  performance
requirements  continuing to be a restriction on the transfer of the Restricted
Stock,  as set forth  below in  Section 4 of this  Agreement.  Therefore,  the
parties hereby reform and amend the Acquisition Agreement as follows:


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<PAGE>

            (A)   Section 1.3 of the Acquisition  Agreement is hereby reformed
and amended to require the  release of the  Restricted  Stock from the escrow,
immediately  following the execution of this  Agreement.  The parties agree to
terminate the escrow as set forth in Section 5 of this Agreement.

            (B)   Sections  1.5,  1.6,  1.7,  1.8 and  1.9 of the  Acquisition
Agreement are hereby  deleted in their  entirety,  and  substantially  similar
sections thereto are inserted into Section 1 of the Stockholders Agreement, as
set forth below in Section 4 of this Agreement.

      4.    REFORMATION  AND  AMENDMENT  OF THE  STOCKHOLDERS  AGREEMENT.  The
parties hereby agree that the  Restricted  Stock shall be subject to the terms
and  conditions  of the  Stockholders  Agreement  retroactive  to the Original
Effective Date, subject to the following restrictions, terms and conditions:

            (A)   Section 1 of the  Stockholders  Agreement is hereby reformed
and  amended  to  reflect  that the  Restricted  Stock is subject to cash flow
performance  requirements and certain other provisions  formerly  contained in
the Acquisition Agreement.  Accordingly, the first full paragraph of Section 1
of the  Stockholders  Agreement is renumbered as subparagraph (a) of Section 1
thereof,  the last  sentence  of Section 1 of the  Stockholders  Agreement  is
deleted in its entirety and, in lieu thereof, the following language is hereby
inserted as new subparagraph (b) of Section 1 of the Stockholders Agreement:

            "(b)  RESTRICTED  STOCK.  (1) Two Million Eight  Hundred  Thousand
            (2,800,000)  shares of the ZMAX Stock  issued to the  Stockholders
            (the  "Restricted  Stock")  shall not be subject to sale,  pledge,
            encumbrance,  gift,  bequest,  or other transfer or disposal under
            any  circumstance  whatsoever,  unless and until  such  shares are
            released  from such  restrictions  under this  Section  1(b).  The
            Restricted Stock will be released quarterly to the Stockholders on
            a pro rata  basis to each  Stockholder.  One  share of  Restricted
            Stock will be  released  for each  $1.25 of Cash Flow (as  defined
            below)  generated by CSI. For purposes of this Section  1(b),  the
            term "Cash  Flow"  means,  with  respect  to each CSI fiscal  year
            quarter or other  period,  all  operating  revenues from sales and
            services  and  licensing  and  franchising  income (but  excluding
            proceeds from loans or capital  infusions and proceeds from sales,
            exchanges and other  dispositions of property or rights not in the
            ordinary  course of  business),  LESS  direct  operating  expenses
            including software licensing fees and a provision for CSI's income
            taxes calculated based on the then-applicable statutory rates (but
            excluding  capital  expenses,  depreciation,   amortization,  debt
            service,  dividends  and  intercompany  charges other than charges
            that would be direct operating expenses if paid by CSI). Cash Flow
            will be determined by Arthur  Andersen (or such other  independent
            accounting  firm then serving  CSI) for the  relevant  period on a
            cash basis.  Upon the  completion  of the review and filing of the
            required SEC financial reports for the applicable quarter,  and in
            no case later than  ninety (90) days  following  the close of such
            financial  quarter,  ZMAX will cause Arthur  Andersen to prepare a
            statement  of Cash Flow  ("Cash Flow  Statement")  for each fiscal


                                      4

<PAGE>

            year quarter which will set forth an itemized  calculation of Cash
            Flow and calculate  the number of shares of  Restricted  Stock (to
            the nearest whole number of shares) based on the Cash Flow for the
            relevant  period and to deliver the Cash Flow  Statement  to ZMAX.
            Upon  receipt of the Cash Flow  Statement,  ZMAX will fax the Cash
            Flow Statement to each Stockholder. Upon approval of the Cash Flow
            Statement as  evidenced by the signing of the Cash Flow  Statement
            by both ZMAX and each  Stockholder,  such shares will no longer be
            deemed  Restricted  Stock for purposes of this Agreement and shall
            be subject to the remaining provisions of this Agreement.

                  (2) If ZMAX and the  Stockholders  cannot  agree on the Cash
            Flow Statement prepared by the independent accounting firm for any
            quarter,  the ZMAX Board of Directors will prepare and sign a Cash
            Flow Statement and fax it to the  Stockholders.  If the ZMAX Board
            of Directors' Cash Flow Statement is approved by the Stockholders,
            as evidenced by the  signatures of the  Stockholders,  such shares
            will no longer be deemed  Restricted  Stock for  purposes  of this
            Agreement and shall be subject to the remaining provisions of this
            Agreement.  If the  Stockholders  are not satisfied  with the Cash
            Flow  Statement  prepared  by the  ZMAX  Board of  Directors  (the
            "Dispute"),  the  Stockholders  may submit the  Dispute to binding
            arbitration  administered by the American Arbitration  Association
            ("AAA") under its Commercial Arbitration Rules, except where those
            rules are  supplemented  or modified by the express  terms of this
            section.  The  parties  agree  that  binding  arbitration  is  the
            exclusive  remedy for resolving any Dispute.  The Stockholders may
            initiate  arbitration  by  sending  notice  of  its  intention  to
            arbitrate the Dispute to ZMAX, which notice must be accompanied by
            a brief  setting  forth the nature of the  Dispute  and the remedy
            sought,   which   brief  may  not  exceed  25  typed   pages  (the
            "Arbitration  Notice").  The  Stockholders  must  also file at the
            regional office of the AAA three copies of the Arbitration  Notice
            and Brief and the arbitration provision of this Agreement together
            with the required  filing fee.  ZMAX must file a responsive  brief
            within  15   business   days  of  receipt  of  the   Stockholders'
            Arbitration  Notice  and  Brief,  which  responsive  brief may not
            exceed 25 typed  pages.  Any  arbitration  proceedings  will be in
            Washington,  D.C.  If  the  parties  are  able  to  agree  on  one
            arbitrator  within 15 days of the date the  Arbitration  Notice is
            filed with the AAA, the Dispute will be heard by that  arbitrator.
            If the  parties  are  unable to agree on one  arbitrator,  then an
            arbitrator   will  be  selected   from  an  impartial   roster  of
            arbitrators  provided by the AAA in accordance with the AAA rules.
            There  will  be no  discovery  permitted  by  the  parties  in the
            arbitration proceedings provided that each party will be permitted
            to take one oral deposition of the other party or unless otherwise
            mutually agreed to by the parties. ZMAX agrees to be bound by Rule
            30(b)(6) of the Federal Rules of Civil  Procedures  "Deposition of
            an  Organization,"  as amended from time to time or any  successor
            rule. The arbitrator  will issue a decision  within 30 days of his


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<PAGE>

            or her appointment.  The decision of the arbitrator must set forth
            in reasonable detail the reasoning  supporting the decision of the
            arbitrator.  The decision rendered by the arbitrator will be final
            and binding on the parties and judgment on the  decision  rendered
            by the arbitrator may be entered in any court having jurisdiction.
            Each  party  will pay its own costs and  expenses  related  to the
            arbitration   procedures.   This   agreement   to   arbitrate   is
            specifically  enforceable under the prevailing arbitration law and
            survives the termination of this Agreement.

                  (3) If any  Stockholder  is  terminated by CSI for cause (as
            defined in the  Stockholder's  employment  agreement  with CSI) or
            violates  the  non-competition,  non-solicitation  or  proprietary
            information restrictions in his employment agreement with CSI, the
            Restricted  Stock issued in the name of the  Stockholder  shall be
            delivered to the Transfer Agent of ZMAX for reissuance in the name
            of ZMAX.

                  (4) The Stockholders will be entitled to vote the Restricted
            Stock even  though it is subject  to the  restrictions  in Section
            1(b)(1)  hereof.  If an  annual  or  special  meeting  of the ZMAX
            stockholders  is called,  the  Stockholders  will be  entitled  to
            receive notice of such meeting and to attend such meeting and vote
            all of the shares of  Restricted  Stock issued in their names,  in
            person or by proxy.

                  (5) The  Stockholders  are entitled to receive  dividends or
            other  distributions  made by  ZMAX  (including  distributions  in
            liquidation) on the Restricted Stock."

            (B)   The  restrictive  legend  set  forth  in  Section  11 of the
Stockholders Agreement is hereby amended to delete the second paragraph of the
legend and the following language is hereby inserted in lieu thereof:

            "Notice  is  hereby  given  that  the  sale,  assignment,  pledge,
            hypothecation,  transfer  or other  disposition  of the  shares of
            Stock  represented  by this  certificate  is restricted  under the
            terms of a Stockholders Agreement dated as of November 6, 1996, as
            amended (the "Stockholders Agreement"), a copy of which is on file
            at the office of the Corporation, and all of the provisions of the
            amended  Stockholders  Agreement are  incorporated by reference in
            this certificate."

            (C)   The notice  provisions  of  Section  14 of the  Stockholders
Agreement  are  hereby  amended,  by  substituting  the  following  names  and
addresses in lieu of those shown in the original Stockholders Agreement:


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<PAGE>

      "If to the Corporation:          ZMAX Corporation
                                       20251 Century Boulevard, Suite 400
                                       Germantown, Maryland  20874
                                       Attention: James T. McCubbin
                                       Telephone: 301-353-9500
                                       Fax: 301-353-9501

      If to the Stockholders:          Michael C. Higgins
                                       12408 Rivers Edge Drive
                                       Potomac, Maryland  20854
                                       Telephone:  301-926-6771

      And/or (as applicable):          Michael S. Cannon
                                       142 Brightmoor Court
                                       Henderson, Nevada  89014
                                       Telephone: 702-270-4503"

            (D)   The termination provisions of Section 15 of the Stockholders
Agreement  are  hereby  amended to  reflect  an  extension  of the term of the
Stockholders Agreement with respect to the Restricted Stock, as follows:

            "15. TERMINATION OF AGREEMENT.  With the exception of Section 1(b)
            of this  Agreement,  this Agreement will be effective for a period
            of three (3) years from the date of this  Agreement  [November  6,
            1996].  The  restrictions   contained  in  Section  1(b)  of  this
            Agreement  shall be effective  for a period of five (5) years from
            the date of this Agreement."

      5.    REFORMATION AND AMENDMENT OF THE SEPARATION  AGREEMENT.  Section 5
of the  Separation  Agreement  is hereby  reformed  and amended to reflect the
changes made by this Agreement, as follows:

            "5.  RESTRICTED   STOCK.  The  holder  hereof   acknowledges  that
            1,400,000  shares of ZMAX  Corporation  ("ZMAX") common stock (the
            "Restricted  Stock") is subject to transfer  restrictions  imposed
            under the Stockholders Agreement, dated as of November 6, 1996, as
            amended from time to time (the  "Stockholders  Agreement"),  among
            ZMAX, Michael S. Cannon and Michael C. Higgins.  The holder hereby
            acknowledges and agrees that his Restricted Stock will be released
            from  the   restrictions   only  if  the  cash  flow   performance
            requirements  of that section are met, and until  released,  shall
            not  be  subject  to  sale,  pledge,  hypothecation,  transfer  or
            disposal in any manner whatsoever."

      6.    TERMINATION  OF THE ESCROW  AGREEMENT.  The parties agree that the
Escrow  Agreement  shall  terminate  immediately  following  execution of this
Agreement.  To that end,  the  parties  agree to notify  the  Escrow  Agent in
writing of such termination of the Escrow Agreement,  with such written notice
from the  parties  hereto to the  Escrow  Agent to be in the form of Exhibit A


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<PAGE>

attached hereto and made part hereof. ZMAX shall use its best efforts to cause
the  Escrow  Agent to deliver  to ZMAX the  Escrow  Shares (as  defined in the
Escrow  Agreement)  in a timely  manner.  Upon  receipt by ZMAX of such Escrow
Shares,  ZMAX shall deliver the certificates  evidencing such Escrow Shares to
its  Transfer  Agent  with  instructions  for the  Transfer  Agent to  reissue
replacement certificates therefor which contain the new restrictive legend set
forth above in Section 4(b) of this Agreement.

      7.    MISCELLANEOUS.

            (a)   NO OTHER AMENDMENTS. Except as reformed and modified by this
Agreement,   the  Stockholders  Agreement,   the  Acquisition  Agreement,  the
Separation  Agreement,  and the Higgins Employment  Agreement remain unchanged
and in full  force and  effect.  The  Escrow  Agreement  shall be deemed to be
terminated retroactive as of the Original Effective Date.

            (b)   COUNTERPARTS.  This Agreement 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 document.

            (c)   GOVERNING LAW; SEVERABILITY. This Agreement will be governed
by and  construed  in  accordance  with  the laws of the  State  of  Maryland,
excluding that body of law pertaining to conflict of laws. If any provision of
this Agreement is for any reason found to be  unenforceable,  the remainder of
this Agreement will continue in full force and effect.

            (d)   DUE AUTHORIZATION. The Agreement is has been duly authorized
by the parties, and duly executed on behalf of each party,  including the duly
authorized officers of ZMAX in the manner required by all laws and regulations
applicable to ZMAX.

            (e)   ASSIGNMENT.  This  Agreement  may be assigned  only with the
advance written consent of the non-assigning party.


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<PAGE>

      IN WITNESS  WHEREOF,  the parties hereto have executed this Agreement as
of the Agreement Date.


Attest/Witness:                        ZMAX Corporation, Inc., a
                                       Delaware corporation


By:    /s/JAMES T. MCCUBBIN            By:    /s/MICHAEL C. HIGGINS
       --------------------                   ---------------------
Name:  James T. McCubbin               Name:  Michael C. Higgins
Its:   Assistant Secretary             Its:   President

 /s/JAMES T. MCCUBBIN                  /s/MICHAEL C. HIGGINS
 --------------------                  ---------------------
 James T. McCubbin                     Michael C. Higgins
                                       President


 /s/JAMES T. MCCUBBIN                  /s/MICHAEL S. CANNON
 --------------------                  --------------------
 James T. McCubbin                     Michael S. Cannon