**Exhibit4.12**

SUPPLEMENTALINDENTURE NO. 6

THIS SUPPLEMENTALINDENTURE NO. 6 (this “Supplemental Indenture”), dated as of November 28,2006, is among Electrolyte Acquisition Subsidiary, Inc., a Delaware corporation(the “Guaranteeing Subsidiary”), subsidiary of EmCare, Inc., a Delawarecorporation, the Issuers (as defined in the Indenture referred to herein), theother Guarantors (as defined in the Indenture) and U.S. Bank Trust NationalAssociation, as trustee under the Indenture referred to below (the “Trustee”).

W I T N E S S E TH

WHEREAS, theIssuers and the Guarantors party thereto have heretofore executed and deliveredto the Trustee an indenture (the “Indenture”), dated as of February 10,2005 providing for the issuance of 10% Senior Subordinated Notes due 2015 (the “Notes”);

WHEREAS, theIndenture provides that under certain circumstances the Guaranteeing Subsidiaryshall execute and deliver to the Trustee a supplemental indenture pursuant towhich the Guaranteeing Subsidiary shall unconditionally guarantee all of theIssuers’ Obligations under the Notes and the Indenture on the terms andconditions set forth herein (the “Subsidiary Guarantee”); and

WHEREAS, pursuantto Section 9.01 of the Indenture, the Trustee is authorized to execute anddeliver this Supplemental Indenture.

NOW THEREFORE, inconsideration of the foregoing and for other good and valuable consideration,the receipt of which is hereby acknowledged, the Guaranteeing Subsidiary andthe Trustee mutually covenant and agree for the equal and ratable benefit ofthe Holders of the Notes as follows:

1.             Capitalized Terms.  Capitalized terms used herein withoutdefinition shall have the meanings assigned to them in the Indenture.

2.             Agreement to Guarantee.  The Guaranteeing Subsidiary hereby agrees asfollows:

(a)           Along with all other Guarantors, tojointly and severally unconditionally Guarantee to each Holder of a Noteauthenticated and delivered by the Trustee and to the Trustee and itssuccessors and assigns, irrespective of the validity and enforceability of theIndenture, the Notes or the obligations of the Issuers hereunder or thereunder,that:

(i)            the principal of and interest on theNotes will be promptly paid in full when due, whether at maturity, byacceleration, redemption or otherwise, and interest on the overdue principal ofand interest on the Notes, if any, if lawful, and all other obligations of theIssuers to the Holders or the Trustee hereunder or thereunder will be promptlypaid in full or performed, all in accordance with the terms hereof and thereof;and

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(ii)           in case of any extension of time ofpayment or renewal of any Notes or any of such other obligations, that samewill be promptly paid in full when due or performed in accordance with theterms of the extension or renewal, whether at stated maturity, by accelerationor otherwise.  Failing payment when dueof any amount so guaranteed or any performance so guaranteed for whateverreason, the Guarantors shall be jointly and severally obligated to pay the sameimmediately.  Each Guarantor agrees thatthis is a guarantee of payment and not a guarantee of collection.

(b)           The obligations hereunder shall beunconditional, irrespective of the validity, regularity or enforceability ofthe Notes or the Indenture, the absence of any action to enforce the same, anywaiver or consent by any Holder of the Notes with respect to any provisionshereof or thereof, the recovery of any judgment against the Issuers, any actionto enforce the same or any other circumstance which might otherwise constitutea legal or equitable discharge or defense of a Guarantor.  Subject to Section 6.06 of the Indenture,each Guarantor hereby waives diligence, presentment, demand of payment, filingof claims with a court in the event of insolvency or bankruptcy of an Issuer,any right to require a proceeding first against an Issuer, protest, notice andall demands whatsoever and covenant that this Subsidiary Guarantee shall not bedischarged except by complete performance of the obligations contained in theNotes and the Indenture.

(c)           If any Holder or the Trustee isrequired by any court or otherwise to return to the Issuers, the Guarantors, orany Custodian, Trustee, liquidator or other similar official acting in relationto either the Issuers or the Guarantors, any amount paid by either to theTrustee or such Holder, this Subsidiary Guarantee, to the extent theretoforedischarged, shall be reinstated in full force and effect.

(d)           The Guaranteeing Subsidiary shall notbe entitled to any right of subrogation in relation to the Holders in respectof any obligations guaranteed hereby until payment in full of all obligationsguaranteed hereby.  The GuaranteeingSubsidiary further agrees that, as between the Guarantors, on the one hand, andthe Holders and the Trustee, on the other hand, (x) the maturity of theobligations guaranteed hereby may be accelerated as provided in Article 6 ofthe Indenture for the purposes of this Subsidiary Guarantee, notwithstandingany stay, injunction or other prohibition preventing such acceleration inrespect of the obligations guaranteed hereby, and (y) in the event of anydeclaration of acceleration of such obligations as provided in Article 6 of theIndenture, such obligations (whether or not due and payable) shall forthwith becomedue and payable by the Guarantors for the purpose of this SubsidiaryGuarantee.  The Guarantors shall have theright to seek contribution from any non-paying Guarantor so long as theexercise of such right does not impair the rights of the Holders under theGuarantee.

(e)           Pursuant to Section 11.03 of theIndenture, after giving effect to any maximum amount and any other contingentand fixed liabilities that are relevant under any applicable Bankruptcy orfraudulent conveyance laws, and after giving effect to any collections from,rights to receive contribution from or payments made by or on behalf of anyother Guarantor in respect of the obligations of such other Guarantor underArticle 11 of the Indenture shall result in the obligations of such Guarantorunder its Subsidiary Guarantee not constituting a fraudulent transfer orconveyance.

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3.             Execution and Delivery.  Each Guaranteeing Subsidiary agrees that theSubsidiary Guarantees shall remain in full force and effect notwithstanding anyfailure to endorse on each Note a notation of such Subsidiary Guarantee.

4.             Releases.

(a)           The Subsidiary Guarantee of aSubsidiary Guarantor shall be released:

(i)            in connection with any sale or otherdisposition of all or substantially all of the assets of that SubsidiaryGuarantor (including by way of merger or consolidation), if the Issuer thatdirectly or indirectly owns such Subsidiary Guarantor applies the Net Proceedsof such sale or other disposition, in accordance with the applicable provisionsof the Indenture;

(ii)           in connection with the sale of all ofthe capital stock of a Subsidiary Guarantor, if the Issuer that directly orindirectly owns such Subsidiary Guarantor applies the Net Proceeds of thatsale, in accordance with the applicable provisions of the Indenture;

(iii)          in connection with any transactionwhich results in a Subsidiary Guarantor ceasing to be a Restricted Subsidiaryof an Issuer, if the transaction is not in violation of the applicableprovisions of the Indenture;

(iv)          if an Issuer designates any RestrictedSubsidiary of such Issuer that is a Subsidiary Guarantor as an UnrestrictedSubsidiary, in accordance with the applicable provisions of the Indenture; or

(v)           if a Subsidiary Guarantor has nooutstanding Indebtedness after giving effect to such release other thanpursuant to clause (2), (4), (5), (6) (with respect to Permitted RefinancingIndebtedness in respect of Indebtedness initially incurred under clause (2) or(5) only), (7), (10), (11), (12), (13), (14) or (15) of Section 4.09 of the Indentureor pursuant to clause (9) of Section 4.09 of the Indenture (with respect toIndebtedness incurred under any of the foregoing clauses) and an Officers’Certificate certifying the foregoing is presented to the Trustee together witha request to release such Subsidiary Guarantor from its Subsidiary Guarantee.

Upon delivery bythe Issuers to the Trustee of an Officers’ Certificate and an Opinion ofCounsel to the effect that such sale or other disposition was made by theIssuers in accordance with the provisions of the Indenture, including withoutlimitation Section 4.10 of the Indenture, the Trustee shall execute anydocuments reasonably required in order to evidence the release of anySubsidiary Guarantor from its obligations under its Subsidiary Guarantee.

(b)           Any Subsidiary Guarantor not releasedfrom its obligations under its Subsidiary Guarantee shall remain liable for thefull amount of principal of and interest on the Notes and for the otherobligations of any Guarantor under the Indenture as provided in Article 11 ofthe Indenture.

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5.             No Recourse Against Others.  No past, present or future director, officer,employee, incorporator, stockholder or agent of Parent or the GuaranteeingSubsidiary, as such, shall have any liability for any obligations of theIssuers, Parent or any Guaranteeing Subsidiary under the Notes, any Guarantees,the Indenture or this Supplemental Indenture or for any claim based on, inrespect of, or by reason of, such obligations or their creation.  Each Holder of the Notes by accepting a Notewaives and releases all such liability. The waiver and release are part of the consideration for issuance of theNotes.  Such waiver may not be effectiveto waive liabilities under the federal securities laws and it is the view ofthe SEC that such a waiver is against public policy.

6.             NEW YORK LAW TO GOVERN.  THE INTERNAL LAW OF THE STATE OF NEW YORKSHALL GOVERN AND BE USED TO CONSTRUE THIS SUPPLEMENTAL INDENTURE BUT WITHOUTGIVING EFFECT TO APPLICABLE PRINCIPLES OF CONFLICTS OF LAW TO THE EXTENT THATTHE APPLICATION OF THE LAWS OF ANOTHER JURISDICTION WOULD BE REQUIRED THEREBY.

7.             Counterparts. The parties may sign any number of copies of this SupplementalIndenture.  Each signed copy shall be anoriginal, but all of them together represent the same agreement.

8.             Effect of Headings.  The Section headings herein are forconvenience only and shall not affect the construction hereof.

9.             The Trustee. The Trustee shall not be responsible in any manner whatsoever for or inrespect of the validity or sufficiency of this Supplemental Indenture or for orin respect of the recitals contained herein, all of which recitals are madesolely by the Guaranteeing Subsidiary and the Issuers.

[*Remainder of Page Left Intentionally Blank*]

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IN WITNESS WHEREOF,the parties hereto have caused this Supplemental Indenture to be duly executedand attested, all as of the date first above written.

ELECTROLYTE ACQUISITION SUBSIDIARY, INC.

 
| By:    |   | /s/ WILLIAM A. SANGER |   |   |
|--------|--------|-----------------------|--------|--------|
| Name:  |   | William A. Sanger     |   |   |
| Title: |   | President             |   |   |

 

AMR HOLDCO, INC. n/k/a EMSC MANAGEMENT, INC.

 
| By:    |   | /s/ WILLIAM A. SANGER   |   |   |
|--------|--------|-------------------------|--------|--------|
| Name:  |   | William A. Sanger       |   |   |
| Title: |   | Chief Executive Officer |   |   |

 

EMCARE HOLDCO, INC.

 
| By:    |   | /s/ WILLIAM A. SANGER   |   |   |
|--------|--------|-------------------------|--------|--------|
| Name:  |   | William A. Sanger       |   |   |
| Title: |   | Chief Executive Officer |   |   |

 

EMERGENCY MEDICAL SERVICES L.P.

By: Emergency Medical Services Corporation, its general partner

 
| By:    |   | /s/ WILLIAM A. SANGER   |   |   |
|--------|--------|-------------------------|--------|--------|
| Name:  |   | William A. Sanger       |   |   |
| Title: |   | Chief Executive Officer |   |   |

 

AMERICAN MEDICAL RESPONSE, INC.

HANK’S ACQUISITION CORP.

FOUNTAIN AMBULANCE SERVICE, INC.

MEDLIFE EMERGENCY MEDICAL SERVICE, INC.

AMERICAN MEDICAL RESPONSE NORTHWEST, INC.

AMERICAN MEDICAL RESPONSE WEST

 

[Signature Page to SixthSupplemental Indenture]

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METROPOLITAN AMBULANCE SERVICE

AMERICAN MEDICAL RESPONSE OF INLAND EMPIRE

DESERT VALLEY MEDICAL TRANSPORT, INC.

SPRINGS AMBULANCE SERVICE, INC.

AMERICAN MEDICAL RESPONSE OF COLORADO, INC.

INTERNATIONAL LIFE SUPPORT, INC.

MEDEVAC MIDAMERICA, INC.

MEDEVAC MEDICAL RESPONSE, INC.

AMERICAN MEDICAL RESPONSE OF OKLAHOMA, INC.

AMERICAN MEDICAL RESPONSE OF TEXAS, INC.

KUTZ AMBULANCE SERVICE, INC.

AMERICAN MEDICAL RESPONSE HOLDINGS, INC.

AMERICAN MEDICAL RESPONSE MANAGEMENT, INC.

A1 LEASING, INC.

FLORIDA EMERGENCY PARTNERS, INC.

MOBILE MEDIC AMBULANCE SERVICE, INC.

METRO AMBULANCE SERVICE, INC.

METRO AMBULANCE SERVICE (RURAL), INC.

MEDIC ONE AMBULANCE SERVICES, INC.

AMERICAN MEDICAL RESPONSE OF SOUTH CAROLINA, INC.

AMERICAN MEDICAL RESPONSE OF NORTH CAROLINA, INC.

AMERICAN MEDICAL RESPONSE OF GEORGIA, INC.

TROUP COUNTY EMERGENCY MEDICAL SERVICES, INC.

RANDLE EASTERN AMBULANCE SERVICE, INC.

MEDI-CAR SYSTEMS, INC.

MEDI-CAR AMBULANCE SERVICE, INC.

AMERICAN MEDICAL RESPONSE OF TENNESSEE, INC.

PHYSICIANS & SURGEONS AMBULANCE SERVICE, INC.

AMERICAN MEDICAL RESPONSE OF ILLINOIS, INC.

MIDWEST AMBULANCE MANAGEMENT COMPANY

PARAMED, INC.

MERCY AMBULANCE OF EVANSVILLE, INC.

TIDEWATER AMBULANCE SERVICE, INC.

AMERICAN MEDICAL RESPONSE OF CONNECTICUT, INCORPORATED

AMERICAN MEDICAL RESPONSE OF MASSACHUSETTS, INC.

AMERICAN MEDICAL RESPONSE MID-ATLANTIC, INC.

AMBULANCE ACQUISITION, INC.

METRO AMBULANCE SERVICES, INC.

BROWARD AMBULANCE, INC.

ATLANTIC AMBULANCE SERVICES ACQUISITION, INC.

ATLANTIC/KEY WEST AMBULANCE, INC.

ATLANTIC/PALM BEACH AMBULANCE, INC.

SEMINOLE COUNTY AMBULANCE, INC.

LIFEFLEET SOUTHEAST, INC.

 

[Signature Page to SixthSupplemental Indenture]

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AMERICAN MEDICAL PATHWAYS, INC.

ADAM TRANSPORTATION SERVICE, INC.

ASSOCIATED AMBULANCE SERVICE, INC.

PARK AMBULANCE SERVICE INC.

FIVE COUNTIES AMBULANCE SERVICE, INC.

SUNRISE HANDICAP TRANSPORT CORP.

STAT HEALTHCARE, INC.

LAIDLAW MEDICAL TRANSPORTATION, INC.

MERCY, INC.

AMERICAN INVESTMENT ENTERPRISES, INC.

LIFECARE AMBULANCE SERVICE, INC.

TEK, INC.

MERCY LIFE CARE

HEMET VALLEY AMBULANCE SERVICE, INC.

AMERICAN MEDICAL RESPONSE OF SOUTHERN CALIFORNIA

MEDIC ONE OF COBB, INC.

PUCKETT AMBULANCE SERVICE, INC.

AMERICAN MEDICAL RESPONSE DELAWARE VALLEY, LLC

By: American Medical Response Mid-Atlantic, Inc., its sole member

REGIONAL EMERGENCY SERVICES, LP

By: Florida Emergency Partners, Inc., its general partner

PROVIDACARE, L.L.C.

By: American Medical Pathways, Inc., its sole member

AMR BROCKTON, L.L.C.

By: American Medical Response of Massachusetts, Inc., its manager

 
| By:    |   | /s/ RANDEL G. OWEN |   |   |
|--------|--------|--------------------|--------|--------|
| Name:  |   | Randel G. Owen     |   |   |
| Title: |   | Vice President     |   |   |

 

EMCARE HOLDINGS INC.

EMCARE, INC.

EMCARE OF ALABAMA, INC.

EMCARE CONTRACT OF ARKANSAS, INC.

EMCARE OF ARIZONA, INC.

EMCARE OF CALIFORNIA, INC.

EMCARE OF COLORADO, INC.

EMCARE OF CONNECTICUT, INC.

EMCARE OF FLORIDA, INC.

EMCARE OF GEORGIA, INC.

EMCARE OF HAWAII, INC.

EMCARE OF INDIANA, INC.

EMCARE OF IOWA, INC.

[Signature Page to SixthSupplemental Indenture]

 

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EMCARE OF KENTUCKY, INC.

EMCARE OF LOUISIANA, INC.

EMCARE OF MAINE, INC.

EMCARE OF MICHIGAN, INC.

EMCARE OF MINNESOTA, INC.

EMCARE OF MISSISSIPPI, INC.

EMCARE OF MISSOURI, INC.

EMCARE OF NEVADA, INC.

EMCARE OF NEW HAMPSHIRE, INC.

EMCARE OF NEW JERSEY, INC.

EMCARE OF NEW MEXICO, INC.

EMCARE OF NEW YORK, INC.

EMCARE OF NORTH CAROLINA, INC.

EMCARE OF NORTH DAKOTA, INC.

EMCARE OF OHIO, INC.

EMCARE OF OKLAHOMA, INC.

EMCARE OF OREGON, INC.

EMCARE OF PENNSYLVANIA, INC.

EMCARE OF RHODE ISLAND, INC.

EMCARE OF SOUTH CAROLINA, INC.

EMCARE OF TENNESSEE, INC.

EMCARE OF TEXAS, INC.

EMCARE OF VERMONT, INC.

EMCARE OF VIRGINIA, INC.

EMCARE OF WASHINGTON, INC.

EMCARE OF WEST VIRGINIA, INC.

EMCARE OF WISCONSIN, INC.

EMCARE PHYSICIAN PROVIDERS, INC.

EMCARE PHYSICIAN SERVICES, INC.

EMCARE SERVICES OF ILLINOIS, INC.

EMCARE SERVICES OF MASSACHUSETTS, INC.

EMCARE ANESTHESIA SERVICES, INC.

ECEP, INC.

COORDINATED HEALTH SERVICES, INC.

EM-CODE REIMBURSEMENT SOLUTIONS, INC.

EMERGENCY MEDICINE EDUCATION SYSTEMS, INC.

EMERGENCY SPECIALISTS OF ARKANSAS, INC. II

FIRST MEDICAL/EMCARE, INC.

HEALTHCARE ADMINISTRATIVE SERVICES, INC.

OLD STAT, INC.

REIMBURSEMENT TECHNOLOGIES, INC.

STAT PHYSICIANS, INC.

THE GOULD GROUP, INC.

TIFTON MANAGEMENT SERVICES, INC.

TUCKER EMERGENCY SERVICES, INC.

EMERGENCY MEDICAL SERVICES CORPORATION

[Signature Page to SixthSupplemental Indenture]

 

 

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EMS MANAGEMENT LLC

By: EMSC Management, Inc. and EmCare HoldCo, Inc., its members

HELIX PHYSICIANS MANAGEMENT, INC.

NORMAN BRUCE JETTON, INC.

PACIFIC EMERGENCY SPECIALISTS MANAGEMENT, INC.

AMERICAN EMERGENCY PHYSICIANS MANAGEMENT, INC.

PHYSICIAN ACCOUNT MANAGEMENT, INC.

PROVIDER ACCOUNT MANAGEMENT, INC.

CHARLES T. MITCHELL, M.D., INC.

GLOBAL MEDICAL RESPONSE, INC.

AIR AMBULANCE SPECIALISTS, INC.

EMCARE OF MARYLAND LLC,

By: EmCare Holdings Inc. and EmCare, Inc., its members

 
| By:    |   | /s/ WILLIAM A. SANGER   |   |   |
|--------|--------|-------------------------|--------|--------|
| Name:  |   | William A. Sanger       |   |   |
| Title: |   | Chief Executive Officer |   |   |

 

U.S. BANK TRUST NATIONAL ASSOCIATION, as Trustee

 
| By:    |   | /s/ PAUL SCHMALZEL |   |   |
|--------|--------|--------------------|--------|--------|
| Name:  |   | Paul Schmalzel     |   |   |
| Title: |   | Vice President     |   |   |

 

[Signature Page to SixthSupplemental Indenture]

 

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