Trust Agreement

EXECUTION COPY======================================================================================================================================= CREDIT SUISSE FIRST BOSTON MORTGAGE SECURITIES CORP., as Depositor, WELLS FARGO BANK, N.A., as Trust Administrator, and U.S. BANK NATIONAL ASSOCIATION, as Trustee ______________________________________ TRUST AGREEMENT Dated as of May 31, 2006 ______________________________________ Mortgage Trust Certificates, Series 2006-2A======================================================================================================================================= TABLE OF CONTENTS PageARTICLE I DEFINITIONS................................................................................3 Section 1.01. Defined Terms.....................................................................3ARTICLE II CONVEYANCE OF THE UNDERLYING CERTIFICATES; ORIGINAL ISSUANCE OF TRUST CERTIFICATES........11 Section 2.01. Conveyance of the Underlying Certificates........................................11 Section 2.02. Issuance of Trust Certificates...................................................12 Section 2.03. Purposes and Powers of the Trust Fund............................................12ARTICLE III ADMINISTRATION OF THE UNDERLYING CERTIFICATES; PAYMENTS AND REPORTS TO CERTIFICATEHOLDERS.13 Section 3.01. REMIC Provisions.................................................................13 Section 3.02. Collection of Monies.............................................................16 Section 3.03. Establishment of Trust Certificate Account; Deposits in Trust Certificate Account17 Section 3.04. Permitted Withdrawals From the Trust Certificate Account.........................17 Section 3.05. Distributions....................................................................17 Section 3.06. Statements to Certificateholders.................................................18 Section 3.07. Access to Certain Documentation and Information..................................19 Section 3.08. Sale of Defective Assets.........................................................19 Section 3.09. Modification of Underlying Certificates..........................................19 Section 3.10. Allocation of Class A Loss Amounts; Recoveries...................................19 Section 3.11. Compliance with Withholding Requirements.........................................19ARTICLE IV THE TRUST CERTIFICATES....................................................................20 Section 4.01. The Trust Certificates...........................................................20 Section 4.02. Registration of Transfer and Exchange of Trust Certificates......................21 Section 4.03. Mutilated, Destroyed, Lost or Stolen Trust Certificates..........................24 Section 4.04. Persons Deemed Owners............................................................24 Section 4.05. Access to List of Certificateholders' Names and Addresses........................25 Section 4.06. Maintenance of Office or Agency..................................................25 Section 4.07. Book-Entry Certificates..........................................................25 Section 4.08. Notices to Clearing Agency.......................................................26 Section 4.09. Definitive Certificates..........................................................26ARTICLE V THE DEPOSITOR.............................................................................27 Section 5.01. Liability of the Depositor.......................................................27 -i- Section 5.02. Merger, Consolidation or Conversion of the Depositor.............................27 Section 5.03. Limitation on Liability of the Depositor and Others..............................27 Section 5.04. Representation and Warranty of the Depositor.....................................28ARTICLE VI THE TRUSTEE...............................................................................29 Section 6.01. Duties of Trustee................................................................29 Section 6.02. Certain Matters Affecting the Trustee............................................30 Section 6.03. Trustee Not Liable for Trust Certificates........................................31 Section 6.04. Trustee May Own Trust Certificates...............................................31 Section 6.05. Trustee's Fees and Expenses......................................................31 Section 6.06. Eligibility Requirements for Trustee.............................................32 Section 6.07. Resignation and Removal of Trustee...............................................32 Section 6.08. Successor Trustee................................................................33 Section 6.09. Merger or Consolidation of Trustee...............................................33 Section 6.10. Appointment of Co-Trustee or Separate Trustee....................................33 Section 6.11. Office of the Trustee............................................................34ARTICLE VII THE TRUST ADMINISTRATOR...................................................................35 Section 7.01. Duties of Trust Administrator....................................................35 Section 7.02. Certain Matters Affecting the Trust Administrator................................36 Section 7.03. Trust Administrator Not Liable for Trust Certificates............................37 Section 7.04. Trust Administrator May Own Trust Certificates...................................37 Section 7.05. Trust Administrator's Fees and Expenses..........................................37 Section 7.06. Eligibility Requirements for Trust Administrator.................................38 Section 7.07. Resignation and Removal of Trust Administrator...................................39 Section 7.08. Successor Trust Administrator....................................................40 Section 7.09. Merger or Consolidation of Trust Administrator...................................40 Section 7.10. Appointment of Co-Trust Administrator or Separate Trust Administrator............40 Section 7.11. Office of the Trust Administrator................................................41ARTICLE VIII TERMINATION...............................................................................42 Section 8.01. Termination......................................................................42 Section 8.02. Additional Termination Requirements..............................................42ARTICLE IX EXCHANGE ACT REPORTING....................................................................43 Section 9.01. Commission Reporting.............................................................43 Section 9.02. Form 10-D Reporting..............................................................43 -ii- Section 9.03. Form 10-K Reporting..............................................................44 Section 9.04. Form 8-K Reporting...............................................................45 Section 9.05. Delisting; Amendment; Late Filing of Reports.....................................46 Section 9.06. Annual Statements of Compliance..................................................47 Section 9.07. Annual Assessments of Compliance.................................................47 Section 9.08. Accountant's Attestation.........................................................48 Section 9.09. Sarbanes-Oxley Certification.....................................................48ARTICLE X MISCELLANEOUS PROVISIONS..................................................................49 Section 10.01. Amendment........................................................................49 Section 10.02. Counterparts.....................................................................50 Section 10.03. Limitation on Rights of Certificateholders.......................................50 Section 10.04. Governing Law....................................................................51 Section 10.05. Notices..........................................................................51 Section 10.06. Notices to the Rating Agencies...................................................51 Section 10.07. Severability of Provisions.......................................................52 Section 10.08. Successors and Assigns...........................................................52 Section 10.09. Article and Section Headings.....................................................52 Section 10.10. Action under and Conflicts with Underlying Pooling Agreement.....................52Exhibit A.........FORM OF CLASS A CERTIFICATEExhibit B.........FORM OF CLASS AR CERTIFICATEExhibit C-1.......FORM OF TRANSFEREE AFFIDAVIT AND AGREEMENTExhibit C-2.......FORM OF TRANSFEROR CERTIFICATEExhibit D.........UNDERLYING POOLING AGREEMENTExhibit E.........FORM OF MONTHLY STATEMENT TO CERTIFICATEHOLDERSExhibit F.........ADDITIONAL FORM 10-D DISCLOSUREExhibit G.........ADDITIONAL DISCLOSURE NOTIFICATIONExhibit H.........ADDITIONAL FORM 10-K DISCLOSUREExhibit I.........FORM 8-K DISCLOSURE INFORMATIONExhibit J.........FORM OF BACK-UP CERTIFICATIONExhibit K.........RELEVANT SERVICING CRITERIA -iii- This TRUST AGREEMENT (this "Agreement"), dated as of May 31, 2006, is among CREDIT SUISSE FIRST BOSTON MORTGAGE SECURITIESCORP., a Delaware corporation (together with its permitted successors and assigns, the "the Depositor"), WELLS FARGO BANK, N.A., aDelaware corporation, as certificate administrator (together with its permitted successors and assigns, the "Trust Administrator"),and U.S. BANK NATIONAL ASSOCIATION, a New York banking corporation, as Trustee (together with its permitted successors and assigns,the "Trustee"). PRELIMINARY STATEMENT The Depositor intends to sell the Trust Certificates (as defined herein), to be issued hereunder in eight classes, which inthe aggregate will evidence the entire beneficial ownership interest in the Underlying Certificates (as defined herein). As providedherein, the Trust Administrator will make an election to treat the entire segregated pool of assets described in the definition ofTrust Fund, as a real estate mortgage investment conduit for federal income tax purposes, and such segregated pool of assets will bedesignated as the "REMIC." The Class AR Certificates will represent the sole class of "residual interests" in the REMIC for purposesof the REMIC Provisions (as defined herein) under federal income tax law. The REMIC Regular Certificates (as defined herein)represent the "regular interests" in the REMIC. The "latest possible maturity date" (determined solely for purposes of satisfyingTreasury regulation Section 1.860G-1(a)(4)(iii)) for the REMIC Regular Certificate shall be the first Distribution Date that followsthe stated maturity date for the Underlying Certificates. The following table sets forth the designation, type, Pass-Through Rate (as defined herein), aggregate initial ClassPrincipal Balance (as defined herein), initial ratings and certain other features of each Class of Trust Certificate comprising theinterests in the Trust Fund (as defined herein). Aggregate Initial Class Pass-Through Principal Minimum Designation Rate Balance Features Fitch/SaeP Denominations(1) Form(2)___________________________________________________________________________________________________________________________ Class 2-A-1-1 Adjustable(3) $272,419,295.06 Adjustable Rate AAA/AAA $25,000.00 Book-Entry Class 2-A-1-2 Adjustable(3) $ Adjustable Rate AAA/AAA $25,000.00 Book-Entry 16,117,596.10 Class AR Adjustable(3) $ Adjustable AAA/AAA (4) Definitive 50.00 Rate/Residual_________________________________________(1) The Trust Certificates, other than the Class AR Certificates, shall be issuable in minimum dollar denominations as indicated above (by Class Principal Balance) and integral multiples of $1 in excess thereof.(2) The Class 2-A-1-1 and Class 2-A-1-2 Certificates shall be Book-Entry Certificates. The Class AR Certificates shall be delivered to the Holders thereof in physical form.(3) With respect to each Distribution Date, the Pass-Through Rate on each Class of Trust Certificates shall be a per annum rate equal to the Pass-Through Rate of the Underlying Certificates for such Distribution Date as defined in the Underlying Pooling Agreement.(4) The Class AR Certificates shall be issuable in minimum denominations of not less than a 20% Percentage Interest. All things necessary to make this Agreement a valid declaration of trust by the Depositor in accordance with its terms havebeen done. In consideration of the premises and the mutual agreements herein contained, the Depositor, the Trust Administrator and theTrustee agree as follows: ARTICLE I DEFINITIONS Section 1.01. Defined Terms. All references to the words "real estate mortgage investment conduit" herein shall have the meaning assigned to suchwords in Section 860D of the Code. Additionally, whenever used in this Agreement, the following words and phrases, unless thecontext otherwise requires, shall have the following meanings: Accrual Period: For any Class of Trust Certificates and any Distribution Date, the calendar month immediatelypreceding such Distribution Date. Additional Disclosure Notification: As defined in Section 9.02. Additional Form 10-D Disclosure: As defined in Section 9.02. Additional Form 10-K Disclosure: As defined in Section 9.03. Adverse REMIC Event: Shall have the meaning set forth in Section 3.01(f) hereof. Affiliate: An "affiliate" of, or person "affiliated" with, a specific person, is a person that directly, orindirectly through one or more intermediaries, controls or is controlled by, or is under common control with, the person specified. Agreement: This Trust Agreement and all amendments hereof and supplements hereto. Available Funds: With respect to any Distribution Date, an amount equal to the amount received on the UnderlyingCertificates on such Distribution Date less amounts withdrawn pursuant to Section 3.04(ii), plus any amounts deposited to the TrustCertificate Account pursuant to Section 5.04 or otherwise on deposit in the Certificate Account as of such Distribution Date pursuantto Section 3.03. Beneficial Holder: A Person holding a beneficial interest in any Trust Certificate through a Participant or anIndirect Participant or a Person holding a beneficial interest in any Definitive Certificate. Book-Entry Certificate: Any Trust Certificate registered in the name of the Depository or its nominee. Initially,the Class A Certificates shall be Book-Entry Certificates. Business Day: As defined in the Underlying Pooling Agreement. Certificate Balance: With respect to any Trust Certificate at any date, the maximum dollar amount of principal towhich the Holder thereof is then entitled hereunder, such amount being equal to the Denomination thereof (i) minus (1) alldistributions of principal previously made with respect thereto and (2) all allocations of Class A Loss Amounts previously allocatedwith respect thereto pursuant to Section 3.10(a) and (ii) plus the amount of any increase to the Certificate Balance of such TrustCertificate in respect of Recoveries pursuant to Section 3.10(b). Certificateholder or Holder: The Person in whose name a Trust Certificate is registered in the CertificateRegister, except that, solely for the purpose of giving any consent pursuant to this Agreement (except as required pursuant to Section -3- 10.01), any Trust Certificate registered in the name of the Depositor or any Affiliate thereof shall be deemed not to be outstandingand the Percentage Interest evidenced thereby or Voting Rights assigned thereto shall not be taken into account in determiningwhether the requisite amount of Percentage Interests or Voting Rights, as the case may be, necessary to effect such consent has beenobtained; provided, however, that if any such Person (including the Depositor or any Affiliate thereof) owns 100% of the PercentageInterests evidenced by a Class of Trust Certificates or of the Voting Rights assigned thereto, such Trust Certificates shall be takeninto account for purposes of any provision hereof that requires the consent of the Holders of Trust Certificates of a particularClass as a condition to the taking of any action hereunder. The Trust Administrator and the Trustee are entitled to relyconclusively on a certification of the Depositor or any Affiliate of the Depositor in determining which Trust Certificates areregistered in the name of an Affiliate of the Depositor. Certificate Register: The register maintained pursuant to Section 4.02 hereof which shall provide for theregistration of Trust Certificates and of transfers and exchanges of Trust Certificates, as herein provided. Class: Collectively, all of the Trust Certificates bearing the same designation. Class A Certificate: Any of the Class 2-A-1-1 Certificates or Class 2-A-1-2 Certificates executed and delivered bythe Trust Administrator substantially in the form annexed hereto as Exhibit A evidencing an interest designated as a "regularinterest" in the REMIC for purposes of the REMIC Provisions. Class A Loss Amount: With respect to the Class A Certificates and on each Distribution Date, the excess of theClass Principal Balance of the Class A Certificates over the Underlying Certificate Balance, in each case after giving effect to alldistributions on or prior to such Distribution Date. Class AR Certificate: Any one of the Class AR Certificates executed and delivered hereunder by the TrustAdministrator substantially in the form annexed hereto as Exhibit B, evidencing an interest designated as the "residual interest" inthe Trust Fund for purposes of the REMIC Provisions. Class Interest Shortfall: With respect to any Distribution Date and each Class of Trust Certificates, the amount bywhich the amount described in clause (i) of the definition of Interest Distribution Amount for such Class, exceeds the amount ofinterest actually distributed on such Class on such Distribution Date. Class Principal Balance: With respect to any Class and as to any date of determination, the aggregate of theCertificate Balances of all Certificates of such Class as of such date. Class Unpaid Interest Amounts: With respect to any Distribution Date and each Class of Trust Certificates, theamount by which the aggregate Class Interest Shortfalls for such Class on prior Distribution Dates exceeds the amount distributed onsuch Class on prior Distribution Dates pursuant to clause (ii) of the definition of Interest Distribution Amount. Closing Date: May 31, 2006. Code: The Internal Revenue Code of 1986, as amended. Commission: The U.S. Securities and Exchange Commission. -4- Corporate Trust Office: With respect to the Trustee, the designated office of the Trustee at which at anyparticular time its corporate trust business with respect to this Agreement shall be administered, which office at the date of theexecution of this Agreement is located at 60 Livingston Avenue, St. Paul, Minnesota 55107, Attention: Corporate Trust- StructuredFinance. With respect to the Trust Administrator, the designated office of the Trust Administrator at which at any particular timeits corporate trust business with respect to this Agreement shall be administered, which office at the date of the execution of thisAgreement is located at 9062 Old Annapolis Road, Columbia, MD 21045, Attention: CSFB ARMT 2006-2A, except for purposes ofSection 4.06 and certificate transfer purposes, such term shall mean the office or agency of the Trust Administrator located at WellsFargo Bank, N.A., 6th Street and Marquette Avenue, Minneapolis, Minnesota 55479, Attention: CSFB ARMT 2006-2A. Definitive Certificate: As defined in Section 4.07. Denomination: With respect to each Trust Certificate, the amount set forth on the face thereof as the "InitialCertificate Balance of this Certificate" or the Percentage Interest appearing on the face thereof. Depositor: Credit Suisse First Boston Mortgage Securities Corp. or any successors in interest. Depository: The Depository Trust Company, or any successor Depository hereafter named. The nominee of the initialDepository for purposes of registering those Trust Certificates that are to be Book-Entry Certificates is Cede ae Co. The Depositoryshall at all times be a "clearing corporation" as defined in Section 8-102(a)(5) of the Uniform Commercial Code of the State of NewYork and a "clearing agency" registered pursuant to the provisions of Section 17A of the Exchange Act. Depository Participant: A broker, dealer, bank or other financial institution or other Person for whom from time totime a Depository effects book-entry transfers and pledges of securities deposited with the Depository. Disqualified Organization: Any organization defined as a "disqualified organization" under Section 860E(e)(5) ofthe Code, which includes any of the following: (i) the United States, any State or political subdivision thereof, any possession ofthe United States, or any agency or instrumentality of any of the foregoing (other than an instrumentality which is a corporation ifall of its activities are subject to tax and, except for the FHLMC, a majority of its board of directors is not selected by suchgovernmental unit), (ii) a foreign government, any international organization, or any agency or instrumentality of any of theforegoing, (iii) any organization (other than certain farmers' cooperatives described in Section 521 of the Code) which is exemptfrom the tax imposed by Chapter 1 of the Code (including the tax imposed by Section 511 of the Code on unrelated business taxableincome), (iv) rural electric and telephone cooperatives described in Section 1381(a)(2)(C) of the Code, (v) an "electing largepartnership" within the meaning of Section 775 of the Code, and (vi) any other Person so designated by the Trust Administrator basedupon an Opinion of Counsel that the holding of an Ownership Interest in a Residual Certificate by such Person may cause the REMIC orany Person having an Ownership Interest in any Class of Certificates (other than such Person) to incur a liability for any federaltax imposed under the Code that would not otherwise be imposed but for the Transfer of an Ownership Interest in a ResidualCertificate to such Person. The terms "United States," "State" and "international organization" shall have the meanings set forth inSection 7701 of the Code or successor provisions. Distribution Date: The 25th day of each month, or if such 25th day is not a Business Day, the next succeedingBusiness Day, commencing on the First Distribution Date. -5- Eligible Account: Either (i) an account or accounts maintained with a federal or state chartered depositoryinstitution or trust company acceptable to the Rating Agencies or (ii) an account or accounts the deposits in which are insured bythe FDIC to the limits established by such corporation, provided that any such deposits not so insured shall be maintained in anaccount at a depository institution or trust company whose commercial paper or other short term debt obligations (or, in the case ofa depository institution or trust company which is the principal subsidiary of a holding company, the commercial paper or other shortterm debt obligations of such holding company) have been rated by each Rating Agency in its highest short term rating category, or(iii) a segregated trust account or accounts (which shall be a "special deposit account") maintained with the Trustee, the TrustAdministrator or any other federal or state chartered depository institution or trust company, acting in its fiduciary capacity, in amanner acceptable to the Trustee, the Trust Administrator and the Rating Agencies. ERISA: The Employee Retirement Income Security Act of 1974, as amended. Exchange Act: The Securities Exchange Act of 1934, as amended, and the rules and regulations thereunder. FDIC: The Federal Deposit Insurance Corporation or any successor. First Distribution Date: June 26, 2006. Fitch: Fitch Ratings or any successor thereto. Form 8-K Disclosure Information: As defined in Section 9.04. Independent: When used with respect to any specified Person, such a Person who (i) is in fact independent of theDepositor, (ii) does not have any direct financial interest in the Depositor or in an Affiliate, and (iii) is not connected with theDepositor as an officer, employee, promoter, underwriter, trustee, partner, director or person performing similar functions. Initial Class Principal Balance: With respect to each Class of Trust Certificates, the Class Principal Balance ofsuch Class of Trust Certificates as of the Closing Date, as set forth in the Preliminary Statement hereto. Interest Distribution Amount: With respect to any Distribution Date and each Class of Trust Certificates, the sumof (i) one month's interest accrued during the related Accrual Period at the Pass-Through Rate on the related Class PrincipalBalance, subject to reduction pursuant to Sections 3.01(g), 3.05(b), 5.03(a), 5.03(b), 6.05 and 7.05, and (ii) any Class UnpaidInterest Amounts for such Class and Distribution Date. Maturity Date: With respect to each Class of Trust Certificates, the Distribution Date in May 2036. Mortgage Loans: The mortgage loans in which the Underlying Certificates evidence a beneficial ownership interest. Non-United States Person: Any Person other than a United States Person. Notice of Final Distribution: With respect to the Underlying Certificates, the notice to be provided pursuant tothe Underlying Pooling Agreement to the effect that final distr ...