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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
 Washington, D.C. 20549
 FORM 10-K
 ANNUAL REPORT
PURSUANT TO SECTIONS 13 OR 15(d)
OF THE SECURITIES EXCHANGE ACT OF 1934
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    ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
 SECURITIES EXCHANGE ACT OF 1934
 For the fiscal year ended December 31, 2005
 OR
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    TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF
THE
 SECURITIES EXCHANGE ACT OF 1934
 For
the transition period
from to
 Commission file number 333-110499-215
 Principal Life Income Fundings Trust 15
 (by Principal Life Insurance Company as depositor)
  Iowa
    
    42-0127290(State or other jurisdiction of incorporation or
    
    (I.R.S. Employer Identification No.)organization)
 Principal Life Income Fundings Trust 15
c/o Principal Life Insurance Company, as depositor
711 High Street
Des Moines, Iowa 50392-0001
(515) 247-5111
 (515) 247-5111
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TABLE OF CONTENTS  PART IItem 3. Legal ProceedingsItem 4. Submission of Matters to a Vote of Security HoldersPART IIItem 5. Market for Registrants Common Equity, Related Stockholder Matters and Issuer Purchases of Equity SecuritiesPART IIIItem 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder MattersItem 13. Certain Relationships and Related TransactionsPART IVItem 15. Exhibits, Financial Statement Schedules, and Reports on Form 8-KSIGNATURESEXHIBIT INDEXSection 302 CertificationAnnual Statement of ComplianceReport of Independent Registered Public Accounting Firm    Table of Contents  
 PART I
 
 Item 3. Legal Proceedings.
  
 Item 4. Submission of Matters to a Vote of Security Holders.
  
 PART II
 
 Item 5. Market for Registrants Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities.
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PART III
 
 Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters.
  
 Item 13. Certain Relationships and Related Transactions.
  
 PART IV
 
 Item 15. Exhibits, Financial Statement Schedules, and Reports on Form 8-K.
 Exhibit 31.1
    
    Section 302 Certification.Exhibit 99.1
    
    Indenture Trustee Report of the Trust  Principal Life Income
Fundings Trust 15 made no payment of interest or principal on its
Floating Rate Secured Medium-Term Notes due 2011 during the fiscal
year ended December 31, 2005. As such, no Indenture Trustee Reports
were prepared or are included in this Annual Report on Form 10K.Exhibit 99.2
    
    Annual Statement of Compliance by Citibank, N.A.Exhibit 99.3
    
    Report of Independent Registered Public Accounting Firm on Compliance.
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SIGNATURES
  PRINCIPAL LIFE INSURANCE COMPANY(Registrant)Date: March 24, 2006
    
    By:
    
    /s/ Karen A. PearstonName: Karen A. PearstonTitle: Second Vice President and Counsel
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EXHIBIT INDEX
 ExhibitNumber
    
    DescriptionExhibit 31.1
    
    Section 302 Certification.Exhibit 99.1
    
    Indenture Trustee Report of the Trust  Principal Life Income
Fundings Trust 15 made no payment of interest or principal on its
Floating Rate Secured Medium-Term Notes due 2011 during the fiscal
year ended December 31, 2005. As such, no Indenture Trustee Reports
were prepared or are included in this Annual Report on Form 10K.Exhibit 99.2
    
    Annual Statement of Compliance by Citibank, N.A.Exhibit 99.3
    
    Report of Independent Registered Public Accounting Firm on Compliance.
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