Exhibit 3.21

                       LIMITED LIABILITY COMPANY AGREEMENT
                                       OF
                 AMERICAN MEDICAL RESPONSE DELAWARE VALLEY, LLC

          This Limited Liability Company Operating Agreement dated as of
February _, 2005 (this "Agreement") of American Medical Response Delaware
Valley, LLC (the "Company") is made and entered into by American Medical
Response Mid-Atlantic, Inc., as the 100% member of the Company (the "Member").

          The Member, by the filing of the certificate of formation with the
Delaware Secretary of States, has formed a limited liability company pursuant to
and in accordance with the Delaware Limited Liability Company Act, 6 Del.C.
Section 18-101 et seq. (as amended from time to time, the "Act"), and hereby
agrees as follows:

                                    ARTICLE I

                                  Introduction

          Section 1.1. Formation of Limited Liability Company. The name of the
limited liability company is American Medical Response Delaware Valley, LLC. The
Member is, hereby authorized to execute, deliver and file any amendments and/or
restatements of its certificate of formation (the "Certificate"), and any other
certificates and any amendments and/or restatements thereof as are necessary or
appropriate for the Company to qualify to do business in a jurisdiction in which
the Company may conduct business. The Company's business shall be conducted
under such name until such time as the Member shall hereafter designate
otherwise and file amendments to the Certificate in accordance with applicable
law.

          This Agreement is subject to, and governed by, the Act and the
Certificate. In the event of a direct conflict between the provisions of this
Agreement and the mandatory provisions of the Act or the provisions of the
Certificate, such provisions of the Act or the Certificate, as the case may be,
will be controlling.

          Section 1.2. Term. The Company was formed upon the filing of its
Certificate and shall continue until it is dissolved and its affairs wound up in
accordance with the Act.

          Section 1.3. Defined Terms. The terms used in this Agreement with
their initial letters capitalized shall, unless the context otherwise requires
or unless otherwise expressly provided herein, have the respective meanings
specified in this Section 1.3.

          "Affiliate" means, as to any Person, any other Person that, directly
or indirectly, is in Control of, is Controlled by or is under common Control
with such Person or is a director or officer of such Person.

          "Capital Contribution" means the total value of cash and agreed gross
fair market value of property contributed and agreed to be contributed to the
Company by the Member, as



shown on Exhibit A, as the same may be amended from time to time. Additional
Capital Contributions may be made by the Member.

          "Code" means the Internal Revenue Code of 1986, as amended. All
references herein to sections of the Code shall include any corresponding
provision or provisions of succeeding law.

          "Control" (including the terms "Controlling" and "Controlled by")
means the possession, directly or indirectly, of the power to direct or cause
the direction of the management and policies of a Person, whether through the
ownership of voting securities or voting interests, by contract or otherwise.

          "Distribution" means any distribution of cash or other property made
by the Company to the Member. None of (i) the repayment of any loan made by the
Member to the Company, (ii) any payment of fees to the Member, or (iii) any
reimbursement of disbursements shall be considered a Distribution hereunder.

          "Initial Capital Contribution" means the initial contribution by the
Member to the capital of the Company pursuant to this Agreement, as reflected on
Exhibit A hereto.

          "Membership Interest" in the Company means the entire ownership
interest of the Member in the Company at any particular time, including the
Member's interest in the capital, profits and losses of the Company and the
right of the Member to any and all benefits to which the Member may be entitled
as provided in this Agreement and under the Act (including the right to receive
distributions hereunder), together with the obligations of the Member to comply
with all of the terms and provisions of this Agreement and under the Act.

          "Person" means an individual, partnership, corporation (including a
business trust), joint stock company, limited liability company, trust,
unincorporated association, joint venture or other entity, or a government or
any political subdivision or agency thereof.

          Section 1.4. Company Purposes. The purposes of the Company are to
engage in any activity permitted to limited liability companies under the laws
of the State of Delaware.

                                   ARTICLE II

                           Member, Membership Interest

          Section 2.1. Name, Address and Initial Capital Contribution; Principal
Office.

          (a) The Member, its Initial Capital Contribution to the Company, its
taxpayer identification number and its address are set forth on Exhibit A.

          (b) The principal office of the Company shall be located at the
address set forth on Exhibit A for the Member, or as the Member may otherwise
determine.

          (c) The registered agent for the service of process and the registered
office in the State of Delaware shall be that Person and location reflected in
the Certificate. The Member


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may, from time to time, change the registered agent or office through
appropriate filing with the Secretary of State of the State of Delaware. In the
event the registered agent ceases to act as such for any reason or the
registered office shall change, the Member shall promptly designate a
replacement registered agent or file a notice of change of address, as the case
may be.

          Section 2.2. Additional Capital Contributions. In order to obtain
additional funds or for other business purposes, the Member may decide to make
additional Capital Contributions to the Company. Any such additional Capital
Contributions shall be in such amounts as determined by the Member and may be in
cash or any type of property. The Member shall not be required to make any
Capital Contributions to the Company other than the Initial Capital
Contribution.

          Section 2.3. Member Loans. Loans by the Member to the Company shall
not be considered additional contributions to the capital of the Company unless
otherwise agreed by the Member.

          Section 2.4. Membership Interest. Distributions with respect to the
Membership Interest shall be made in accordance with Article V.

          Section 2.5. Certificate for Membership Interest. The Membership
Interest of the Member may be represented by a certificate or may be
uncertificated. The exact contents of any such certificate shall be determined
by the Member.

          Section 2.6. Capital and Capital Account.

          (a) No interest shall be paid on any Capital Contribution.

          (b) A capital account (the "Capital Account") shall be established and
maintained on behalf of the Member.

          (c) The Member shall not receive out of Company property any part of
its Capital Contributions until all liabilities of the Company, except
liabilities to the Member on account of its Capital Contributions, have been
paid or there remains property of the Company sufficient to pay them.

          Section 2.7. Limitation on Liability. The Member shall not be liable
under a judgment, decree or order of a court, or in any other manner, for a
debt, obligation or liability of the Company, except as provided by law or as
specifically provided otherwise herein. The Member shall not be required to loan
any funds to the Company. The Member shall not be required to make any
contribution to the Company by reason of any negative balance in the Member's
Capital Account, nor shall any negative balance in the Member's Capital Account
create any liability on the part of the Member to any third party.

          Section 2.8. Bankruptcy or Dissolution of a Member. The occurrence of
any of the events specified in Section 18-304(a)(1) through (6) or 18-304(b) of
the Act shall not result in the Member ceasing to be a member of the Company.


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                                   ARTICLE III

                       Management and Control of Business

          Section 3.1. Management of the Company. The overall management and
control of the business and affairs of the Company shall be vested in the
Member, who shall be responsible for the management of the Company's business.

          Section 3.2. Authority and Responsibility of the Member. All decisions
respecting any matter set forth in this Agreement or otherwise affecting or
arising out of the conduct of the business of the Company shall be made by the
Member, and the Member shall have the exclusive right and full authority to
manage, conduct and operate the Company's business.

          Section 3.3. Duties of Parties.

          (a) The Member shall devote such time to the business and affairs of
the Company as is necessary to carry out the Member's duties set forth in this
Agreement.

          (b) Nothing in this Agreement shall be deemed to restrict in any way
the rights of the Member, or any Affiliate of the Member, to conduct any other
business or activity whatsoever, and neither the Member nor any Affiliate of the
Member shall be accountable to the Company with respect to such other business
or activity even if such other business or activity competes with the Company's
business.

          (c) The Member understands and acknowledges that the conduct of the
Company's business may involve business dealings and undertakings with the
Member and its Affiliates. In any of those cases, those dealings and
undertakings shall be at arm's length and on commercially reasonable terms, as
determined in the business judgment of the Member.

          Section 3.4. Liability and Indemnification.

          (a) The Member shall not be liable, responsible or accountable, in
damages or otherwise, to the Company for any act performed by the Member with
respect to Company matters, except for fraud, gross negligence or an intentional
breach of this Agreement.

          (b) The Company shall indemnify the Member for any act performed by
the Member with respect to Company matters, except for fraud, gross negligence
or an intentional breach of this Agreement by the Member.

                                   ARTICLE IV

                             Accounting and Records

          Section 4.1. Records and Accounting. The books and records of the
Company shall be kept, and the financial position and the results of its
operations recorded, at the expense of the Company in accordance with the
accounting methods elected to be followed by the Company for federal income tax
purposes. The books and records of the Company shall reflect


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all Company transactions and shall be appropriate and adequate for the Company's
business. The fiscal year of the Company for financial reporting and for federal
income tax purposes shall end on August 31 of each year until changed by the
Member.

          Section 4.2. Access to Accounting Records. All books and records of
the Company shall be maintained at any office of the Company or at the Company's
principal place of business, and the Member and the Member's duly authorized
representative shall have access to them at such office of the Company and the
right to inspect and copy them at reasonable times.

          Section 4.3. Income Tax Status and Elections. The Company shall be
treated as a sole proprietorship of the Member for federal and other income tax
purposes consistent with Treasury Regulation Sections 301.7701-2(c)(2)(i) and
301.7701-3(b)(ii) and shall not make any elections for federal income tax
purposes inconsistent therewith.

          Section 4.4. Other Records. The Company shall maintain records at the
principal office of the Company or such other place as the Member may determine
which shall include the following:

          (a) the Capital Account of the Member and the Membership Interest of
the Member;

          (b) a current list of the full name and last known business or mailing
address of the Member;

          (c) a copy of the Certificate of the Company and all amendments
thereto; and

          (d) copies of the Company's currently effective written operating
agreement, copies of any writings permitted or required with respect to the
Member's obligation to contribute cash, property or services to the Company, and
copies of any financial statements of the Company for the three most recent
fiscal years.

                                    ARTICLE V

                    Allocations; Distributions and Interests

          Section 5.1. Distributions. Subject to Section 18-607 of the Act,
distributions of cash and other assets shall be made to the Member from time to
time as determined by the Member.

          Section 5.2. Allocation of Profit or Loss. Profits and losses, and
each item of Company income, gain, loss, deduction and tax preference with
respect thereto, for each fiscal year (or shorter period in respect of which
such items are to be allocated) shall be allocated to the Member, consistent
with the characterization of the Company as a sole proprietorship of the Member
pursuant to Section 4.3.

          Section 5.3. Distributions and Allocations upon Liquidation. Upon
liquidation of the Company (or the Member's Membership Interest), liquidating
distributions will be made


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pursuant to Section 5.1 and in accordance with the positive Capital Account
balance of the Member as of the date of liquidation, as determined after taking
into account all Capital Account adjustments for the Company's taxable year
during which the liquidation occurs.

                                   ARTICLE VI

                              Changes in Membership

          Section 6.1. Change in Membership. The Member shall have the right or
power, directly or indirectly, to sell, assign, transfer, give, hypothecate,
pledge, encumber or otherwise dispose of all or any portion of its interest as a
Member in the Company to any Person (a "Transferee"). Any Transferee may be
admitted as a Member with the consent of, and upon such terms (including the
capital contribution to be made and the Membership Interest to be received) as
may be determined by the Member. Upon the admission of a Transferee as a Member,
Exhibit A annexed hereto shall be amended to reflect each Member's revised
Membership Interest. No Transferee shall become a Member until the Transferee
has become a party to, and adopted all of the terms and conditions of, this
Agreement.

                                   ARTICLE VII

                                   Dissolution

          Section 7.1. Events of Dissolution. The Company shall be dissolved in
accordance with the Act.

          Section 7.2. Effect of Dissolution. Upon dissolution, the Company
shall not be terminated and shall continue until a winding up of the affairs of
the Company is completed and a certificate of dissolution has been issued by the
Secretary of State of Delaware.

          Section 7.3. Procedure for Dissolution. If the Company is dissolved,
the Member shall wind up the Company's affairs. On winding up of the Company,
the assets of the Company shall be applied in the manner, and in the order of
priority, set forth in Section 18-804 of the Act.

          Section 7.4. Filing of Certificate of Cancellation. If the Company is
dissolved, upon completion of the winding up of the Company, the Member shall
promptly file a Certificate of Cancellation with the office of the Delaware
Secretary of State.

                                  ARTICLE VIII

                                  Miscellaneous

          Section 8.1. Complete Agreement. This Agreement and the Certificate
constitute the complete and exclusive statement of the Member, and replace and
supersede all prior agreements and all prior written and oral statements by the
Member with respect to the subject matter hereof. No representation, statement,
condition or warranty not contained in this Agreement or the Certificate will be
binding on the Member or have any force or effect whatsoever with respect to the
subject matter hereof.


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          Section 8.2. Governing Law. This Agreement and the rights of the
parties hereunder will be governed by, interpreted and enforced in accordance
with the laws of the State of Delaware.

          Section 8.3. Binding Effect. Subject to the provisions of this
Agreement relating to transferability, this Agreement will be binding upon and
inure to the benefit of the Member and its successors and assigns.

          Section 8.4. Terms. Common nouns and pronouns will be deemed to refer
to the masculine, feminine, neuter, singular and plural, as the identity of the
person or persons, firm or corporation may in the context require.

          Section 8.5. Headings. All headings herein are inserted only for
convenience and ease of reference and are not to be considered in the
construction or interpretation of any provision of this Agreement.

          Section 8.6. Severability. If any provision of this Agreement is held
to be illegal, invalid or unenforceable under the present or future laws
effective during the term of this Agreement, such provision will be fully
severable; this Agreement will be construed and enforced as if such illegal,
invalid or unenforceable provision had never comprised a part of this Agreement,
and the remaining provisions of this Agreement will remain in full force and
effect and will not be affected by the illegal, invalid or unenforceable
provision or by its severance from this Agreement. Furthermore, in lieu of such
illegal, invalid or unenforceable provision, there will be added automatically
as part of this Agreement a provision as similar in terms to such illegal,
invalid or unenforceable provision as may be possible and be legal, valid and
enforceable.

          Section 8.7. Additional Documents and Acts. The Member agrees to
execute and deliver such additional documents and instruments and to perform
such additional acts as may be necessary or appropriate to effectuate, carry out
and perform all of the terms, provisions and conditions of this Agreement and
the transactions contemplated hereby.

          Section 8.8. No Third Party Beneficiary. This Agreement is made solely
and specifically for the benefit of the Member and its successors and assigns,
and no other Person will have any rights, interest or claims hereunder or be
entitled to any benefits under or on account of this Agreement as a third-party
beneficiary or otherwise.

          Section 8.9. Notices. Any notice to be given or to be served upon the
Company or the Member in connection with this Agreement must be in writing and
will be deemed to have been given and received when delivered to the address
specified by the party to receive the notice. Such notices will be given to the
Member at the address specified in Section 2.1(a) hereof and to the Company at
the address specified in Section 2.1(b). The Member or the Company may, at any
time, designate any other address in substitution of the foregoing address to
which such notice will be given, such notice to be effective upon a Person upon
its receipt.

          Section 8.10. Amendments. All amendments to this Agreement must be in
writing and signed by the Member.


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                            [Signature Page Follows]


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          IN WITNESS WHEREOF, American Medical Response Mid-Atlantic, Inc. has
executed this Agreement to be effective as of the date and year first above
written.

Dated as of February __, 2005.

                                        AMERICAN MEDICAL RESPONSE MID-ATLANTIC,
                                        INC.


                                        By: /s/ Randy Owen
                                            ------------------------------------
                                        Name: Randy Owen
                                        Title:
                                               ---------------------------------

                       [Signature Page to LLC Agreement of
                 American Medical Response Delaware Valley, LLC]


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                                    EXHIBIT A



Member                                         Initial Capital Contribution
- ------                                         ----------------------------
                                            
American Medical Response Mid-Atlantic, Inc.   $100.00
6200 S. Syracuse Way
Suite 200
Greenwood Village, CO 80111



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