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                                                                     EXHIBIT 4.3

                       AMERICAN ONCOLOGY RESOURCES, INC.
                      1993 KEY EMPLOYEE STOCK OPTION PLAN


        1.  PURPOSE.  The purpose of the 1993 Key Employee Stock Option Plan
(the "Plan"), is to provide an additional incentive to eligible key employees,
upon whom rest major responsibilities for the successful operation,
administration, and management of American Oncology Resources, Inc., a Delaware
corporation (the "Company").  It is recognized that the present and potential
contributions of the key employees are important to the continued success of the
Company.  The Plan is also intended to be used to retain highly qualified
persons for the successful conduct of the business of the Company.  It is
intended that these purposes will be enhanced through the awarding of Stock
Options.

        2.  DEFINITIONS.  As used herein the words and phrases below shall have
the following meanings:

            (a) "Board" shall mean the Board of Directors of the Company.

            (b) "Code" shall mean the Internal Revenue Code of 1986, as amended.

            (c) "Committee" shall mean the committee, which shall be comprised
     of at least two and not more than four members who are disinterested
     persons as defined under rules and regulations promulgated under Section
     16(b) of the Exchange Act and who shall be members of the Board, appointed
     by the Board to administer the Plan, which Board shall have the power to
     fill vacancies on the Committee arising by resignation, death, removal or
     otherwise.

            (d) "Common Stock" shall mean the common stock of the Company, $.01
     par value per share, regardless of the series or class.

            (e) "Company" shall mean American Onocology Resources, Inc., a
     Delaware corporation.

            (f) "Disability" shall mean the person so affected is unable to
     engage in substantial gainful activity by reason of any medically
     determinable physical or mental impairment which can be expected to result
     in death or which has lasted or can be expected to last for a continuous
     period of not less than one hundred eighty (180) days. The Committee's
     determination as to whether a Participant has incurred a Disability shall
     be final and conclusive as to all interested parties.

            (g) "Eligible Employee" shall mean a key employee of the Company as
     determined pursuant to Section 4.

            (h) "Exchange Act" shall mean the Securities Exchange Act of 1934,
     as amended.
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          (i) "Fair Market Value" shall mean, with respect to a share of
     Common Stock on any date herein specified, the average daily Closing Price
     per share of Common Stock for the ten (10) consecutive trading days
     commencing fifteen (15) trading days before the date in question. The term
     "Closing Price" of per share of Common Stock for a day or days shall mean
     (i) if the shares of Common Stock are listed or admitted for trading on a
     national securities exchange, the last reported sales price regular way,
     or, in case no such reported sale takes place on such day or days, the
     average of the reported closing bid and asked prices regular way, in either
     case on the principal national securities exchange on which the shares of
     Common Stock are listed or admitted for trading, or (ii) if the shares of
     Common Stock are not listed or admitted for trading on a national
     securities exchange, (A) the last transaction price of the shares of Common
     Stock on the National Association of Securities Dealers Automated Quotation
     System ("NASDAQ") or, in the case no such reported transaction takes place
     on such day or days, the average of the reported closing bid and asked
     prices thereof quoted on NASDAQ, or (B) if the shares of Common Stock are
     not quoted on NASDAQ, the average of the closing bid and asked prices of
     the shares of Common Stock in the over-the-counter market, as reported by
     The National Quotation Bureau, Inc., or an equivalent generally accepted
     reporting service, or (iii) if on any such trading days the shares of
     Common Stock are not quoted by any such organization, the fair market value
     per share of Common Stock on such day(s), as determined in good faith by
     the Committee.

          (j) "Incentive Stock Option" shall mean a stock option granted by the
     Committee to an Eligible Employee under the Plan which is designated by the
     Committee as an Incentive Stock Option and intended to qualify as an
     Incentive Stock Option under Section 422 of the Code.

          (k) "Nonqualified Stock Option" shall mean a stock option granted by
     the Committee to an Eligible Employee under the Plan, which is not
     designated by the Committee as an Incentive Stock Option.

          (l) "Participant" shall mean any individual who has received an award
     of a Stock Option and has not exercised the Stock Option and received the
     Common Stock subject to the Stock Option.

          (m) "Plan" shall mean the 1993 Key Employee Stock Option Plan, as
     herein set forth and as amended from time to time.

          (n) "Retirement" shall mean the termination of employment from the
     Company constituting retirement as determined by the Committee.

          (o) "Securities Act" shall mean the Securities Act of 1933, as now in
     effect or as hereafter amended.

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          (p) "Stock Option" shall mean an Incentive Stock Option or
     Nonqualified Stock Option pursuant to which a Participant is eligible to
     acquire Common Stock pursuant to the terms and conditions of the Plan and
     the Stock Option Agreement.

          (q) "Stock Option Agreement" shall mean the agreement described in
     Section 7.

          (r) "Terminated For Cause" shall mean that a Participant's employment
     is terminated as a result of a breach of his or her written employment
     agreement, if the Participant is subject to a written employment agreement,
     or if the Committee determines that such Participant is being terminated as
     a result of misconduct, dishonesty, disloyalty, disobedience or action that
     might reasonably injure the Company or its business interests or
     reputation.

     3.   ADMINISTRATION OF THE PLAN.  The Plan shall be administered by the
Committee appointed by the Board.  The Committee shall have authority to adopt
rules and regulations for carrying out the Plan, determine the Eligible
Employees, determine the number of Stock Options, if any, to be awarded to each
Eligible Employee, determine whether a Stock Option shall be an Incentive Stock
Option or a Nonqualified Stock Option, determine the exercise price of each
Stock Option, determine the vesting period and vesting conditions for Stock
Options, determine the series or class of Common Stock to be subject to the
Stock Option, determine the Fair Market Value of Common Stock, and interpret,
construe, and implement the provisions of the Plan.  Decisions of the Committee
(including decisions regarding the interpretation and application of the Plan)
shall be binding on the Company and on all Participants and other interested
parties.  The Committee shall hold its meetings at such times and places as it
deems advisable.  All members of the Committee shall constitute a quorum for a
meeting.  All determinations of the Committee shall be made by a majority of its
members attending the meeting.  Furthermore, any decision or determination
reduced to writing and signed by a majority of the members of the Committee
shall be as effective as if it had been made by a majority vote at a meeting
properly called and held.

     4.   ELIGIBLE EMPLOYEES.  The individuals who shall be eligible to
participate in the Plan shall be such key employees (including officers who may
be members of the Board of Directors) of the Company, or of any subsidiary of
the Company, as the Committee shall determine from time to time.  No person will
be eligible for the grant of any Incentive Stock Option who owns or would own
immediately before the grant of such Incentive Stock Option, directly or
indirectly, stock possessing more than ten percent of the total combined voting
power of all classes of stock of the Company, a subsidiary or a parent
corporation.  This restriction does not apply if, at the time such Incentive
Stock Option is granted, the Incentive Stock Option exercise price is at least
110% of the Fair Market Value on the date of grant and the Incentive Stock
Option by its terms is not exercisable after the expiration of five years from
the date of grant.  For the purpose of this Section 4, the attribution rules of
Section 424(d) of the Code shall apply for the purpose of determining an
Eligible Employee's percentage ownership.

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     5.   SHARES OF COMMON STOCK SUBJECT TO THE PLAN.    The number of shares of
Common Stock available for Stock Options shall equal 5% of the sum of the
Company's outstanding Common Stock as of the effective date of the Plan plus the
number of shares of Common Stock issued by the Company after such effective
date; provided, however, that the number of shares available for Incentive Stock
Options shall not exceed 31,324 shares; and provided further, however, that all
outstanding and previously exercised Stock Options shall be applied against the
number of shares of Common Stock available under the Plan.  The shares of Common
Stock available under the Plan may consist of shares of any series of Common
Stock provided that the rights of such shares to dividends, to liquidation
proceeds and to share in the appreciation in the value of the Company shall be
not less than the rights of any other series of Common Stock.  If any Stock
Option shall expire or terminate for any reason, without being exercised, shares
of Common Stock subject to such Stock Option shall again be available for grant
in connection with grants of subsequent Stock Options.

     6.   STOCK OPTION TERMS.

          (a) Exercise Price.  The exercise price per share of Common Stock
     under each Stock Option shall be determined by the Committee; provided,
     however, that with respect to a Nonqualified Stock Option, such exercise
     price shall not be less than 85% of the Fair Market Value per share of such
     Common Stock on the date of grant, as determined by the Committee, and that
     with respect to an Incentive Stock Option, such exercise price shall not be
     less than 100% of the Fair Market Value per share of such Common Stock on
     the date of grant, as determined by the Committee.

          (b) Term.  The Committee shall fix the term of each Stock Option which
     shall be not more than ten years from the date of grant.  In the event no
     term is fixed, such term shall be ten years from the date of grant.

          (c) Exercise; Transferability.  The Committee shall determine the time
     or times at which a Stock Option may be exercised in whole or in part;
     provided, however, that other than as provided in Section 10, in no event
     shall a Stock Option be exercisable before the expiration of six months
     from the date of its grant or after ten years from the date of its grant.
     Stock Options shall not be transferable by the Participant otherwise than
     by will, under the laws of descent and distribution, or pursuant to a
     qualified domestic relations order (as defined by the Code) and shall be
     exercisable only by him or by his duly appointed personal representative.

          (d) Incentive Stock Options.  Anything in the Plan notwithstanding,
     the aggregate Fair Market Value (determined as of the time the Incentive
     Stock Option is granted) of the shares of Common Stock with respect to
     which Incentive Stock Options are exercisable for the first time by any
     Participant during any single calendar year (under the Plan and any other
     incentive stock option plans of the Company and its subsidiaries or any
     parent corporation) shall not exceed the sum of $100,000 (or such other
     limits as may be required by the Code).

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          (e) Method of Exercise. Stock Options shall be exercised by the
     delivery of written notice to the Company setting forth the number of
     shares of Common Stock with respect to which the Stock Option is to be
     exercised and, subject to the subsequent provisions hereof, the address to
     which the certificates representing shares of the Common Stock issuable
     upon the exercise of such Stock Option shall be mailed. In order to be
     effective, such written notice shall be accompanied at the time of its
     delivery to the Company by payment of the exercise price of such shares of
     Common Stock, which payment shall be made in cash or by cashier's check,
     certified check, or postal or express money order payable to the order of
     the Company in an amount (in United States dollars) equal to the exercise
     price of such shares of Common Stock. Such notice shall be delivered in
     person to the Secretary of the Company, or shall be sent by registered
     mail, return receipt requested, to the Secretary of the Company, in which
     case, delivery shall be deemed made on the date such notice is deposited in
     the mail. In its sole and absolute discretion, the Committee may require as
     an additional condition to the issuance of Common Stock upon exercise of a
     Stock Option that the optionee furnish the Committee with an executed copy
     of a shareholder agreement and/or voting agreement in such form as may be
     required by the Committee at the time notice of exercise is delivered to
     the Company. Such shareholder agreement may impose significant restrictions
     on the transfer of the Common Stock received upon exercise of the Stock
     Option. In addition, the Committee may require that there be presented to,
     and filed with it, such evidence as it may deem necessary to establish that
     the shares of Common Stock to be purchased are being acquired for
     investment and not with a view to their distribution.

          (f) Withholding.  Whenever shares of Common Stock are to be issued or
     delivered pursuant to the Plan, the Company shall require the Participant
     to remit to the Company an amount sufficient to satisfy federal, state, and
     local withholding tax requirements prior to the delivery of any certificate
     or certificates for such shares, which payment may be made in the manner
     set forth in clause (e) above or in the manner permitted by clause (g)
     below.  With respect to shares received by a Participant pursuant to the
     exercise of an Incentive Stock Option, if such Participant disposes of any
     such shares within two years from the date of grant of such option or
     within one year after the transfer of such shares to the Participant, the
     Company shall have the right to withhold from any salary, wages or other
     compensation payable by the Company to the Participant an amount sufficient
     to satisfy federal, state and local withholding tax requirements
     attributable to such disposition.

          (g) Alternative Payment for Stock.  Alternatively, payment of the
     exercise price may be made, in whole or in part, by delivery of shares of
     Common Stock previously issued to the Participant.  Unless otherwise
     permitted by the Committee, payment of the exercise price with shares of
     Common Stock shall be made only with shares owned by the Participant for at
     least six (6) months.  If payment is made in whole or in part in shares of
     Common Stock owned by the Participant, then the Participant shall deliver
     to the Company, in payment of the option price of the shares of Common
     Stock

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     with respect to which such Stock Option is exercised, (i) certificates
     registered in the name of such Participant representing a number of shares
     of Common Stock legally and beneficially owned by such Participant, free of
     all liens, claims and encumbrances of every kind and having a Fair Market
     Value as of the date of delivery of such notice that is not greater than
     the exercise price of the shares of Common Stock with respect to which such
     Stock Option is to be exercised, such certificates to be accompanied by
     stock powers duly endorsed in blank by the record holder of the shares
     represented by such certificates; and (ii), if the exercise price of the
     shares of Common Stock with respect to which such Stock Option is to be
     exercised exceeds such Fair Market Value, cash or a cashier's check,
     certified check, or postal or express money order payable to the order of
     the Company in an amount (in United States dollars) equal to the amount of
     such excess.

          The Company may extend and maintain, or arrange for the extension and
     maintenance of, financing to any Participant to purchase shares pursuant to
     exercise of a Stock Option and/or to pay withholding taxes on such terms as
     may be approved by the Committee in its sole discretion.  In considering
     the terms for extension or maintenance of credit by the Company, the
     Committee shall, among other factors, consider the cost to the Company of
     any financing extended by the Company.

          (h) Notification with Respect to Incentive Stock Options.  Any
     Participant who disposes of shares of Common Stock acquired on the exercise
     of an Incentive Stock Option by sale or exchange either (i) within two
     years after the date of the grant of the Incentive Stock Option under which
     the stock was acquired or (ii) within one year after the transfer of such
     shares to such Participant pursuant to exercise shall notify the Company of
     such disposition and of the amount realized and of the adjusted basis in
     such shares.

     7.   STOCK OPTION AGREEMENT.  The Stock Options awarded to an Eligible
Employee shall be evidenced by a separate written agreement (the "Stock Option
Agreement") which shall be subject to the terms and provisions of the Plan, and
which shall be signed by the Participant and by the President or a Vice-
President of the Company, other than the Participant, in the name of and on
behalf of the Company.  The Stock Option Agreement shall contain such provisions
as the Committee in its discretion deems advisable.  In the event of any
inconsistency or conflict between the terms of the Plan and a Stock Option
Agreement, the terms of the Plan shall govern.

     8.   TERMINATION OF EMPLOYMENT, DEATH, DISABILITY AND RETIREMENT.

          (a) Termination of Employment.  If a Participant's employment is
     terminated for any reason whatsoever other than death, Disability or
     Retirement, with respect to any Stock Option granted pursuant to the Plan
     outstanding at the time, unless otherwise established by the Committee, no
     further vesting shall occur and the Participant shall be entitled to
     exercise his or her rights with respect to the portion of the Stock Option
     vested

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     as of the date of termination for a period expiring on the earlier of (i)
     the expiration date set forth in the Stock Option Agreement or (ii) thirty
     (30) calendar days after such termination date and, thereafter, the Stock
     Option and the Participant's rights thereunder shall be completely
     terminated; provided, however, that if a Participant is Terminated for
     Cause, such Participant's right to exercise the vested portion of his or
     her Stock Option shall terminate as of 12:01 a.m. on the date of
     termination of employment.

          (b) Retirement.  Unless otherwise approved by the Committee, upon the
     Retirement of a Participant:

               (i)  any nonvested portion of any outstanding Stock Option shall
          immediately terminate and no further vesting shall occur;

               (ii)  any vested Nonqualified Stock Option shall expire on the
          earlier of (A) the expiration date set forth in the Stock Option
          Agreement with respect to such Nonqualified Stock Option; or (B) the
          expiration of one year after the date of Retirement; and

               (iii) any vested Incentive Stock Option shall expire on the
          earlier of (A) the expiration date set forth in the Stock Option
          Agreement with respect to such Incentive Stock Option; or (B) the
          expiration of three (3) months after the date of Retirement.

          (c) Death or Disability.  Upon termination of employment as a result
     of death or Disability:

               (i)  50% of any nonvested portion of any outstanding Stock Option
          shall immediately and fully vest notwithstanding the original vesting
          schedule;

               (ii)  any vested Nonqualified Stock Option (including those
          vested pursuant to Section (c)(i)) shall expire upon the earlier of
          (A) the expiration date set forth in the Stock Option Agreement with
          respect to such Nonqualified Stock Option or (B) the first anniversary
          of such termination of employment as a result of death or Disability;
          and

               (iii) any vested Incentive Stock Option (including those vested
          pursuant to Section (c)(i)) shall expire upon the earlier of (A) the
          expiration date set forth in the Stock Option Agreement with respect
          to such Incentive Stock Option or (B) the expiration of three (3)
          months after such termination of employment as a result of death and
          the first anniversary of such termination of employment as a result of
          Disability.

     9.   REQUIREMENTS OF LAW.      The Company shall not be required to sell or
issue any shares of Common Stock under any Stock Option if the issuance of such
shares shall

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constitute a violation by the Participant or the Company of any provision of any
law, statute, or regulation of any governmental authority whether it be Federal
or State.  Specifically, in connection with the Securities Act, upon exercise of
any Stock Option, unless a registration statement under the Securities Act is in
effect with respect to the shares of Common Stock covered by such Stock Option,
the Company shall not be required to issue such shares unless the Committee has
received evidence satisfactory to it to the effect that the holder of such Stock
Option is acquiring such shares of Common Stock for investment and not with a
view to the dis tribution thereof, and that such shares of Common Stock may
otherwise be issued without registration under the Securities Act or State
securities laws. Any determination in this connection by the Committee shall be
final, binding and conclusive. The Company may, but shall in no event be
obligated to, register any securities covered hereby pursuant to the Securities
Act. The Company shall not be obligated to take any affirmative action in order
to cause the exercise of a Stock Option, or the issuance of shares pursuant
thereto, to comply with any law or regulation of any governmental authority.

     10.  CHANGE IN STOCK AND ADJUSTMENTS.  The existence of outstanding Stock
Options shall not affect in any way the right or power of the Company or its
stockholders to make or authorize any or all adjustments, recapitalizations,
reorganizations or other changes in the Company's capital structure or its
business, or any merger or consolidation of the Company, or any issue of bonds,
debentures, preferred or prior preference stock ahead of, or affecting, the
Common Stock or the rights thereof, or the dissolution or liquidation of the
Company, or any sale or transfer of all or any part of its assets or business,
or any other corporate act or proceeding, whether of a similar character or
otherwise.

     If the Company shall effect a subdivision or consolidation of shares or
other capital readjustment, the payment of a stock dividend, or other increase
or reduction of the number of shares of Common Stock outstanding, without
receiving compensation therefor in money, services or property, then (a) the
number, class, and per share price of shares of Common Stock subject to
outstanding Stock Options hereunder shall be appropriately adjusted in such a
manner as to entitle a Participant to receive upon exercise of a Stock Option,
for the same aggregate cash consideration, the same total number and class of
shares as he would have received had he exercised his Stock Option in full
immediately prior to the event requiring the adjustment; and (b) the number and
class of shares then reserved for issuance under the Plan shall be adjusted by
substituting for the total number and class of shares of Common Stock then
reserved that number and class of shares of Common Stock that would have been
received by the owner of an equal number of outstanding shares of each class of
Common Stock as the result of the event requiring the adjustment.

     After a merger of one or more corporations into the Company or after a
consolidation of the Company and one or more corporations in which the Company
is the surviving corpo ration, each holder of an outstanding Stock Option, upon
exercise of such Stock Option, shall be entitled to receive (at no additional
cost but subject to any required action by stockholders) in lieu of the number
and class of shares of Common Stock with respect to which such Stock Option is
exercisable, the number and class of shares of stock (or other securities or

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consideration) to which such holder would have been entitled pursuant to the
terms of the agreement of merger or consolidation if, immediately prior to such
merger or consolidation, such holder had been the holder of record of the same
number and class of shares of Common Stock which he would have otherwise
received upon exercise of such Stock Option.

     If the Company is merged into or consolidated with another corporation
under circumstances where the Company is not the surviving corporation, or if
the Company is liquidated, or sells or otherwise disposes of substantially all
its assets to another corporation while unexercised Stock Options remain
outstanding under the Plan, (i) subject to the provisions of clause (iii) below,
after the effective date of such merger, consolidation, liquidation, or sale, as
the case may be, each holder of an outstanding Stock Option shall be entitled,
upon exercise of such Stock Option, to receive at no additional cost, in lieu of
shares of Common Stock, shares of such stock (or other securities or
consideration) as the holders of shares of Common Stock received pursuant to the
terms of the merger, consolidation, liquidation, or sale; (ii) unless otherwise
provided in the Participant's Stock Option Agreement, any limitations set forth
in or imposed pursuant to Section 8 hereof shall automatically lapse so that all
Stock Options, from and after a thirty (30) day period preceding the effective
date of such merger, consolidation, liquidation or sale, as the case may be,
shall be exercisable in full; and (iii) all outstanding Stock Options may be
canceled by the Board as of the effective date of any such merger,
consolidation, liquidation or sale provided that (a) notice of such cancellation
shall be given to each holder of a Stock Option, and (b) unless otherwise
provided in the Participants's Stock Option Agreement, each holder of a Stock
Option shall have the right to exercise such Stock Option in full (without
regard to any limitations set forth in or imposed pursuant to Section 8 hereof)
during a thirty (30) day period preceding the effective date of such merger,
consolidation, liquidation, or sale.  In the event the acceleration of vesting
provided by clause (ii) or (iii) above would result in imposition of the excise
tax imposed by Section 4999 of the Code, a Participant may elect to waive such
acceleration with respect to such number of shares subject to unvested Stock
Options as the Participant shall designate, and the Participant shall be
entitled to designate from among his unvested Stock Options those Stock Options
which shall not be subject to accelerated vesting.

     Except as expressly provided herein, the issue by the Company of shares of
stock of any class, or securities convertible into shares of stock of any class,
for cash, property, labor, or services, either upon direct sale, exercise of
rights or warrants to subscribe therefor, or conversion of shares or obligations
of the Company convertible into such shares or other securities, shall not
affect, and no adjustment by reason thereof shall be made with respect to,
the number, class or price of shares of Common Stock then subject to outstanding
Stock Options.

     11.  NO RIGHTS AS STOCKHOLDER.  A holder of a Stock Option shall have no
rights as a stockholder with respect to any shares of Common Stock until the
issuance of a stock certificate for such shares.  Except as otherwise provided
in Section 10, no adjustment shall be made for dividends (ordinary or
extraordinary, whether in cash, securities, or other property)

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or distributions or other rights for which the record date is prior to the date
such stock certificate is issued.

     12.  NO EFFECT ON EMPLOYMENT RELATIONSHIP.  Participation in the Plan shall
not confer upon any employee any right to continue in the employ of the Company
or interfere in any way with the right of the Company to terminate any
employee's employment at any time.

     13.  NO FUND ESTABLISHED.  It is not intended that awards under this Plan
be set aside in a trust which would qualify as an employee's trust within the
meaning of sections 401 or 402 of the Internal Revenue Code of 1986, as amended,
or in any other type of trust, fund, or separate account.  The rights of any
Participant and any person claiming under such Participant shall not rise above
or exceed those of an unsecured creditor of the Company.

     14.  NO ASSIGNMENT OR ALIENATION OF BENEFITS.  Except as contemplated by
Section 6(c), no right or benefit under this Plan shall be subject to
anticipation, alienation, sale, assignment, pledge, encumbrance, or charge, and
any attempt to anticipate, alienate, sell, assign, pledge, encumber, or charge
the same shall be void.  No right or benefit hereunder shall in any manner be
liable for or subject to any debts, contracts, liabilities, or torts of the
person entitled to such benefits.

     15.  LIABILITY AND INDEMNIFICATION OF COMMITTEE.  No member of the
Committee shall be liable for any act or omission of any other member of the
Committee or for any act or omission on his own part, including but not limited
to the exercise of any power or discretion given to him under the Plan, except
those resulting from his own gross negligence or willful misconduct.  The
Company shall indemnify each present and future member of the Committee against,
and each member of the Committee shall be entitled without further act on his
part to indemnity from the Company for all expenses (including the amount of
judgments and the amount of approved settlements made with a view to the
curtailment of costs of litigation) reasonably incurred by him in connection
with or arising out of any action, suit or proceeding in which he may be
involved by reason of his being or having been a member of the Committee,
whether or not he continues to be a member of the Committee at the time of
incurring such expenses; provided, however, that such indemnity shall not
include any expense incurred by any such member of the Committee (a) in respect
of matters as to which he shall be finally adjudged in any such action, suit, or
proceeding to have been guilty of gross negligence or willful misconduct in the
performance of his duty as such member of the Committee, or (b) in respect of
matters in which any settlement is effected in an amount in excess of the amount
approved by the Company on the advice of its legal counsel; and provided
further, that no right of indemnification under the provisions set forth herein
shall be available to or enforceable by any such member of the Committee unless,
within thirty (30) days after institution of any such action, suit, or
proceeding, he shall have offered the Company, in writing, the opportunity to
handle and defend same at its own expense.  This indemnity expressly includes
any claims arising out of or based upon the negligence of the member of the
Committee.  The foregoing right of indemnification shall inure to the benefit of
the heirs, executors, or administrators of

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each such member of the Committee and shall be in addition to all other rights
to which such member of the Committee may be entitled as a matter of law,
contract, or otherwise.

     16.  SUBSTITUTION OPTION.  Stock Options may be granted under this Plan
from time to time in substitution for stock options held by employees (or
nonemployee directors) of another corporation who are about to become employees
(or nonemployee directors) of the Company as the result of a merger or
consolidation with the Company, or the acquisition by the Company of the assets
of the other corporation, or the acquisition by the Company of stock of the
other corporation as the result of which it becomes a subsidiary of the Company.
The terms and conditions of the substitute Stock Options so granted may vary
from the terms and conditions set forth in this Plan to such extent as the Board
at the time of grant may deem appropriate to conform, in whole or in part, to
the provisions of the stock options for which such substitute Stock Options are
granted.

     17.  GENDER, TENSE AND HEADINGS.  Whenever the context requires such, words
of the masculine gender used herein shall include the feminine and neuter, and
words used in the singular shall include the plural.  Section headings as used
herein are inserted solely for convenience and reference and constitute no part
of the construction of this Plan.

     18.  AMENDMENT AND TERMINATION.  The Board may modify, revise or terminate
the Plan at any time and from time to time; provided, however, that without the
further approval of the holders of at least a majority of the outstanding shares
of Common Stock, the Board may not (i) change the aggregate number of shares
which may be issued under Stock Options pursuant to the provisions of the Plan;
(ii) reduce the option price at which Stock Options may be granted to an amount
less than 85% of the Fair Market Value per share at the time the Stock Option is
granted, or otherwise materially increase the benefits accruing to Participants
under the Plan; or (iii) change the class of persons eligible to receive Stock
Options.  No amendment or termination may adversely affect any vested right of a
Participant without the written consent of such Participant.

     19.  NO GUARANTEE OF TAX CONSEQUENCES.  Neither the Company nor the
Committee makes any commitment or guarantee that any federal, state or local tax
treatment will apply or be available to any person participating or eligible to
participate hereunder.

     20.  SEVERABILITY.  In the event that any provision of this Plan shall be
held illegal, invalid or unenforceable for any reason, such provision shall be
fully severable, but shall not affect the remaining provisions of the Plan, and
the Plan shall be construed and enforced as if the illegal, invalid, or
unenforceable provision had never been included herein.

     21.  GOVERNING LAW.  The provisions of the Plan shall be construed,
administered, and governed by the laws of the State of Texas, without giving
effect to principles of conflicts of laws, and, to the extent applicable, the
laws of the United States.

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     22.  EFFECTIVE DATE.  The Plan shall become effective and shall be deemed
to have been adopted on February 17, 1993, if within one year of that date it
shall have been approved by the holders of at least the majority of the
outstanding Common Stock.  No Stock Option shall be granted pursuant to the Plan
after one day more than ten years after the date the Plan was adopted by the
Board or the date the Plan was approved by the stockholders of the Company,
whichever is earlier.

     23.  STOCKHOLDERS APPROVAL.  Notwithstanding any other provisions of the
Plan, in order for the Plan to continue as effective, on or before the date
which occurs twelve (12) months after the date the Plan is adopted by the Board,
the Plan must be approved by the holders of at least a majority of the
outstanding stock (unless applicable state law or the Company's charter or by-
laws require a greater number) of the Company entitled to vote thereon voting in
person, or by proxy, at a duly held stockholders' meeting, and no shares of
Common Stock shall be issued under the Plan until such approval has been
secured.

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     RESOLVED, that first sentence of Section 5 of the Plan is hereby amended to
read in its entirety as follows:

          "The number of shares of Common Stock available for Stock Options
          shall equal 7% of the sum of the Company's outstanding Common Stock
          as of the effective date of the Plan plus the number of shares of
          Common Stock issued by the Company after such effective date
          (including, solely for determining the number of shares available for
          Stock Options, shares of Common Stock agreed to be issued to
          physicians in connection with such physicians' causing their
          respective professional corporations or other entities to enter into
          management service agreements with the Company); provided, however,
          that the number of shares available for Incentive Stock Options shall
          not exceed 375,888 shares; and provided, further, however, that all
          outstanding and previously exercised Stock Options shall be applied
          against the number of shares of Common Stock available under the
          Plan."