EXECUTIVE CHANGE IN CONTROL SEVERANCE PLAN

SYMBION, INC.

EXECUTIVE CHANGE IN CONTROL SEVERANCE PLAN AND

SUMMARY PLAN DESCRIPTION

TABLE OF CONTENTS

INTRODUCTION

This Plan document was adopted effective December 11, 1997, and revised effective May 11, 2000 to reflect that UniPhy Healthcare, Inc. changed its name to Symbion, Inc. The Plan has been amended from time to time and was amended and restated effective March 1, 2006. This document is a summary of your benefits, rights and obligations under the Symbion, Inc. Executive Change in Control Severance Plan (the “Plan”). This document is intended to comply with both the summary plan description and the written plan requirements of the Employee Retirement Income Security Act of 1974 (“ERISA”) and the regulations issued under ERISA by the United States Department of Labor.

Symbion, Inc. (“Symbion”) may generally amend or terminate the Plan at any time prior to a “change in control” (see definitions). For that reason, all statements in this document are subject to change at any time prior to a change in control without notice.

The Plan Administrator has the discretion to interpret the provisions of the Plan and make determinations for the payment of Plan benefits. All such determinations are final, binding and conclusive.

SECTION 1.   In General

Symbion has established the Plan with the intention of providing benefits to Eligible Employees of Symbion and its Affiliates under the conditions described in this document. Plan benefits are intended to provide additional compensation to Eligible Employees whose positions are eliminated or adversely effected following a change in control of Symbion. Therefore, the amount of your benefit is calculated without regard to your actual period of unemployment following a change in control, if any.

This document constitutes the entire written Plan. Any oral or other written expressions of the Plan or related to the Plan or its subject matter are completely superseded by this document. Except for a formal written Plan amendment that is properly adopted by Symbion, or a written modification authorized under Section 9, any oral or written statements concerning the Plan shall not modify or add to this Plan document.

As is more fully explained in Section 4, severance benefits are not provided under this Plan if your employment termination is not connected with a Change in Control.

SECTION 2.   Definitions

Defined terms in the Plan are indicated by initial capitalization of the term. References to a “Section” mean a section of this Plan. Pronouns that refer to one gender include the other gender. “You” or “your” means you, an individual in the employ of Symbion.

a.              “ Administrator ” or “ Plan Administrator ” means the chief executive officer of Symbion. The Administrator may delegate any of his or her duties or authorities to a committee

of the Board of Directors. The Administrator has absolute discretion to make all decisions under the Plan, including making determinations about eligibility for and the amounts of Benefits payable under the Plan and interpreting all Plan provisions. All decisions of the Administrator are final, binding and conclusive. If a Change in Control occurs, as described in Section 2.e, the Administrator shall be the individual who was the chief executive officer of Symbion immediately prior to the Change in Control.

b.              “ Affiliate ” means Symbion and all corporations, partnerships, trusts and other entities that are members, with Symbion, of a controlled group of corporations or a group of trades or businesses under common control under Sections 414(b) and (c) of the Internal Revenue Code.

c.              “ Annual Pay ” means the following items of compensation payable to an Eligible Employee immediately prior to the time of a Change in Control that gives rise to payment of Benefits to the Eligible Employee hereunder:

(1)                                   Normal monthly salary payable on regular payroll dates, as adjusted to an annualized rate.

(2)                                   Cash bonuses (including deferred bonus accruals) normally payable in the fiscal year of Symbion that includes the Change in Control, calculated by reference to (i) the bonus amount that has been determined for the fiscal year, (ii) if no bonus amount has been determined, the bonus payment plan or policy previously adopted by the board of directors of Symbion, or, (ii) if no such plan or policy has been adopted, the amount of bonuses paid in the prior fiscal year (as adjusted for increases in cost of living announced by federal government) to the Eligible Employee or to a similarly situated employee of Symbion or an Affiliate, and as enhanced for increases in the profitability of Symbion or increases in value of shareholder equity.

(3)                                   The value of noncash benefits (taxable or nontaxable) under fringe benefit arrangements of Symbion or an Affiliate normally available to the Eligible Employee, to the extent that such fringe benefits are not otherwise provided to the Eligible Employee as a Benefit pursuant to Section 4

d.              “ Benefit ” means the severance benefits described in Section 3.

e.              “ Change in Control ” means the occurrence at any time during the employment term of an Eligible Employee of any of the following events:

(1)                                   An acquisition (other than directly from the Company) of any voting securities of the Company (the “ Voting Securities ”) by any “ Person ” (as that term is used for purposes of Section 13(d) or 14(d) of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”)), immediately after which such Person has “ Beneficial Ownership ” (within the meaning of Rule 13d-3 promulgated under the Exchange Act) of more than 50% of the combined voting power of the company’s then outstanding voting Securities; provided, however, in determining whether a Change in Control has occurred, Voting Securities which are acquired in a Non-Control Acquisition shall not constitute an acquisition which would cause a Change in Control. A “ Non-Control Acquisition ” shall

mean an acquisition by (1) an employee benefit plan (or a trust forming a part thereof) maintained by (A) the Company, or (B) any corporation or other Person of which a majority of its voting power or its voting equity securities or equity interest is owned, directly or indirectly, by the Company (for purposes of this definition, a “ Subsidiary ”), (2) the Company or its Subsidiaries, or (3) any person in connection with a Non-Control Transaction (as hereinafter defined);

(2)                                   The individuals who, as of the date of this Agreement, are members of the Company’s Board of Directors (the “ Incumbent Board ”), cease for any reason to constitute at least a majority of the members of the Company’s Board of Directors; provided, however, that if the election, or nomination for election by the Company’s stockholders, of any new director was approved by a vote of at least a majority of the Incumbent Board, such new director shall, for purposes of this Agreement, be considered as a member of the Incumbent Board; provided, further, however, that no individual shall be considered a member of the Incumbent Board if such individual initially assumed office as a result of either an actual or threatened “ Election Contest ” (as described in Rule 14a-11 promulgated under the Exchange Act) or other actual or threatened solicitation of proxies or consents by or on behalf of a Person other than the Company’s Board of Directors (a “ Proxy Contest ”) including by reason of any agreement intended to avoid or settle any Election Contest or Proxy Contest; or

(3)                                   Approval by stockholders of the Company of:

(i)                                      A merger, consolidation or reorganization involving the Company, unless such merger, consolidation or reorganization is a Non-Control Transaction. A “ Non-Control Transaction ” shall mean a merger, consolidation or reorganization of the Company where:

(A)                               the stockholders of the company, immediately before such merger, consolidation or reorganization, own directly or indirectly immediately following such merger, consolidation or reorganization, more than 50% of the combined voting power of the outstanding voting securities of the corporation resulting from such merger or consolidation or reorganization (the “ Surviving Corporation ”) in substantially the same proportion as their own ownership of the Voting Securities immediately before such merger, consolidation or reorganization; and

(B)                                 the individuals who were members of the Incumbent Board immediately prior to the execution of the agreement providing for such merger, consolidation or reorganization constitute at least a majority of the members of the board of directors of the Surviving Corporation, or a corporation beneficially directly or indirectly owning a majority of the Voting Securities of the Surviving Corporation;

(ii)           A complete liquidation or dissolution of the Company; or

(iii)                                An agreement for the sale or other disposition of all of the assets of the Company