<PAGE>

                                                                   EXHIBIT 10(a)

                                 PERRIGO COMPANY
                       NONQUALIFIED STOCK OPTION AGREEMENT

            (Under the Perrigo Company 2003 Long-Term Incentive Plan)

To: [Employee's Name]

      Re: Notice of Grant of Nonqualified Stock Option

Dear [First_Name>]:

      This is to notify you that Perrigo Company (the "Company") has granted to
you a nonqualified stock option under the Perrigo Company 2003 Long-Term
Incentive Plan (the "Plan"). The terms and conditions of your nonqualified stock
option are set forth in this Nonqualified Stock Option Agreement (the
"Agreement").

      1.    GRANT. Effective as of (date) (the "Grant Date") and subject to the
terms and conditions contained in this Agreement and in the Plan, the Company
grants to you a nonqualified stock option (the "Option") to purchase [(total
number ] shares of the Company's common stock, without par value ("Common
Stock"), at a per-share price of $(price) (the "Option Price"), which is equal
to the fair market value (as defined in Section 6(a) of the Plan) of such Common
Stock as of the Grant Date.

      2.    TIMING AND DURATION OF EXERCISE.

            (a)   The Option shall vest according to the following Vesting Dates
      and, subject to the requirements of subsection (b) below, may be exercised
      after such Vesting Dates to purchase the number of shares of Common Stock
      set forth opposite each such date:

<TABLE>
<CAPTION>
  Vesting Date    Vested Shares
----------------  -------------
<S>               <C>
Month, day, year  1/5th Shares
Month, day, year  1/5th Shares
Month, day, year  1/5th Shares
Month, day, year  1/5th Shares
Month, day, year  1/5th Shares
</TABLE>

      Notwithstanding the above vesting schedule, the Option shall immediately
      vest in full and, subject to subsection (b) below, may be exercised in
      whole or in part at any time after (1) the occurrence of a Change of
      Control (as defined in Plan Section 12(a)) that occurs while you are
      employed by the Company or one of its subsidiaries, or (2) your death,
      disability (as defined in Plan Section 11(a)) or retirement (as defined in
      Plan Section 11(a)). If your employment with the

<PAGE>

      Company or its subsidiary is terminated for cause (as defined in Plan
      Section 11(c)), all of your rights under the Option, whether or not
      vested, shall terminate immediately.

            (b)   Except as provided elsewhere in this Agreement, the Option to
      purchase Vested Shares must be exercised by you, if at all, while you are
      an employee of the Company or one of its subsidiaries or within three
      months following the termination of your employment, but in no event after
      (date + 10 years, minus 1 day) (the "Expiration Date"). If your employment
      with the Company or its subsidiary is terminated by your retirement (as
      defined in Plan Section 11(a)), death or disability (as defined in Plan
      Section 11(a)), the Option may thereafter be exercised by you, or in the
      event of your death, by your estate or your designated beneficiary, or in
      the event of your disability, by you or your legal representative, at any
      time prior to the Expiration Date. If you die after termination of
      employment and during the period in which the Option is exercisable, the
      right to exercise the Option during such period will be governed by Plan
      Section 11(d). If your employment with the Company or its subsidiary is
      terminated involuntarily for economic reasons as determined by the Board
      of Directors or the Committee, the terms of Plan Section 11(c) shall
      apply.

            Any portion of the Option that is not vested pursuant to this
      Section 2 as of your employment termination date will be forfeited
      immediately except as otherwise provided in Section 11(d) of the Plan with
      respect to Options scheduled to vest within 24 months following
      involuntary termination for economic reasons. If the Option is not
      exercised as to all of the Vested Shares covered by the Option within the
      applicable time period and in the manner provided herein, the Option will
      terminate immediately.

      3.    METHOD OF EXERCISE. The Option, or any part of it, shall be
exercised by written notice directed to the President, Chief Financial Officer
or Secretary of the Company at the Company's principal office in Allegan,
Michigan. Such notice must satisfy the following requirements:

            (a)   The notice must state the Grant Date, the number of shares of
      Common Stock subject to the Option, the number of shares of Common Stock
      with respect to which the Option is being exercised, the person in whose
      name the stock certificate or certificates for such shares of Common Stock
      is to be registered and the person's address and Social Security number
      (or if more than one person, the names, addresses and Social Security
      numbers of such persons).

            (b)   The notice shall be accompanied by check, bank draft, money
      order or other cash payment, or by delivery of a certificate or
      certificates, properly endorsed, for shares of Common Stock that you have
      held for at least six months and that are equivalent in fair market value
      (as defined in Plan Section 6(a)) on the date of exercise to the Option
      Price (or any combination of cash and shares), in full payment of the
      Option Price for the number of shares specified in the notice.

<PAGE>

            (c)   The notice must be signed by the person or persons entitled to
      exercise the Option and, if the Option is being exercised by any person or
      persons other than you, be accompanied by proof, satisfactory to the
      Committee, of the right of such person or persons to exercise the Option.

      The exercise may be with respect to any one or more shares of Common Stock
covered by the Option (to the extent vested), reserving the remainder for a
subsequent timely exercise. The Company shall make prompt delivery of such
shares; provided that if any law or regulation requires the Company to take any
action with respect to such shares before the issuance thereof, then the date of
delivery of such shares shall be extended for the period necessary to take such
action; and provided further that the Company shall have no obligation to
deliver any such certificate unless and until appropriate provision has been
made for any withholding taxes in respect of such exercise. You may elect to
surrender shares of Common Stock previously acquired by you or to have the
Company withhold shares that would have otherwise been issued pursuant to the
exercise of the Option in order to satisfy all or a portion of any such tax
withholding obligation; provided that any withheld shares, or any surrendered
shares that you previously acquired from the Company and have held for less than
six months, may only be used to satisfy the minimum tax withholding required by
law.

      At the time or times you wish to exercise the Option in whole or part,
please refer to the above provisions dealing with the methods and formality of
exercise of the Option and execute the attached Notice of Exercise of Stock
Option and Record of Stock Transfer.

      4.    CONDITIONS TO ISSUANCE OF STOCK CERTIFICATES. The shares of stock
deliverable upon the exercise of the Option, or any portion thereof, may be
either previously authorized but unissued shares or issued shares that have been
re-acquired by the Company. Such shares shall be fully paid or nonassessable.
The Company shall not be required to issue or deliver any certificate or
certificates for shares of stock purchased upon the exercise of the Option or
portion thereof prior to fulfillment of all of the following conditions:

            (a)   The admission of such shares to listing on any and all stock
      exchanges on which such class of stock is then listed;

            (b)   The completion of any registration or other qualification of
      such shares under any state or federal law or under rulings or regulations
      of the Securities and Exchange Commission or of any other governmental
      regulatory body, which the Committee shall, in its discretion, deem
      necessary or advisable;

            (c)   The obtaining of any approval or other clearance from any
      state or federal governmental agency which the Committee shall, in its
      absolute discretion, determine to be necessary or advisable;

<PAGE>

            (d)   The payment to the Company of all amounts which, under
      federal, state or local tax law, it is required to withhold upon exercise
      of the Option; and

            (e)   The lapse of such reasonable period of time following the
      exercise of the Option as the Committee may from time to time establish
      for reasons of administrative convenience.

      5.    NONTRANSFERABILITY. The Option shall not be transferable other than
by will or by the laws of descent and distribution. During your lifetime, the
Option shall be exercisable only by you or by your guardian or legal
representative in the event of your disability. Not withstanding the forgoing,
you may transfer an award to a revocable inter vivos (living) trust created by
you, provided you are the sole beneficiary of such trust during your lifetime
and, provided further, that any restrictions on the transfer of such award
imposed shall apply and extend to the trustee of such trust.

      6.    NO RIGHTS AS A STOCKHOLDER. You shall not have any rights as a
stockholder with respect to any shares of Common Stock subject to the Option
prior to the date of issuance to you of a certificate or certificates for such
shares.

      7.    OPTION SUBJECT TO PLAN. Enclosed for your review is a copy of the
Plan. The granting of the Option is being made pursuant to the Plan and the
Option shall be exercisable only in accordance with the applicable terms of the
Plan. The Plan contains certain definitions, restrictions, limitations and other
terms and conditions all of which shall be applicable to the Option. ALL THE
PROVISIONS OF THE PLAN ARE INCORPORATED HEREIN BY REFERENCE AND ARE MADE A PART
OF THIS AGREEMENT IN THE SAME MANNER AS IF EACH AND EVERY SUCH PROVISION WERE
FULLY WRITTEN INTO THIS AGREEMENT. Should the Plan become void or unenforceable
by operation of law or judicial decision, this Agreement shall have no force or
effect. Nothing set forth in this Agreement is intended, nor shall any of its
provisions be construed, to limit or exclude any definition, restriction,
limitation or other term or condition of the Plan as is relevant to this
Agreement and as may be specifically applied to it by the Committee. In the
event of a conflict in the provisions of this Agreement and the Plan, as a rule
of construction the terms of the Plan shall be deemed superior and apply.

      8.    ADJUSTMENTS IN EVENT OF CHANGE IN COMMON STOCK. In the event of a
stock split, stock dividend, recapitalization, reclassification or combination
of shares, merger, sale of assets or similar event, the number and kind of
shares subject to the Option, and the Option Price may be appropriately adjusted
consistent with such change in such manner as the Committee may deem equitable
to prevent substantial dilution or enlargement of the rights granted to or
available for you.

      9.    OPTION SUBJECT TO EMPLOYEE INVENTION AND NONDISCLOSURE AGREEMENT.
The granting of this Option and your rights to exercise this Option shall at all
times be subject to and conditioned upon your signature and return of the
Company's standard Employee Invention and Nondisclosure Agreement that is to be
signed by each employee of the Company or a subsidiary of the Company and to
your continued compliance with

<PAGE>

the terms and conditions of the Employee Invention and Nondisclosure Agreement.
If at any time you challenge the validity and/or enforceability of the
restrictions imposed under the Employee Invention and Nondisclosure Agreement
for any reason, whether by legal action, by notice to the Company or otherwise,
or if you should otherwise fail or refuse to comply with such restrictions for
any reason, your rights under this Agreement shall terminate and this Agreement
shall become null and void and of no further force or effect as to any
unexercised Options.

      10.   GOVERNING LAW AND JURISDICTION. This Agreement shall be governed by
and interpreted in accordance with the laws of the State of Michigan. Any
proceeding related to or arising out of this Agreement shall be commenced,
prosecuted or continued in the Circuit Court in Kent County, Michigan located in
Grand Rapids, Michigan or in the United Stated District Court for the Western
District of Michigan, and in any appellate court thereof.

                                      ****

      We look forward to your continuing contribution to the growth of the
Company. Please acknowledge your receipt of the Plan and the Option on the
enclosed copy of this Agreement, and return it to us.

Date                                 Very truly yours,

                                     ___________________________________________
                                     Douglas R. Schrank, Chief Financial Officer

<PAGE>

                            ACKNOWLEDGMENT OF RECEIPT

            I acknowledge receipt of the Perrigo Company 2003 Long-Term
Incentive Plan (the "Plan") provided to me on (date). I further acknowledge
receipt of this Nonqualified Stock Option Agreement and agree to the terms and
conditions expressed herein and in the Plan.

(Month)___, year                           _____________________________________
                                           [Employee's Name]