Pricing Supplement Dated December 13, 2005	 	Filed pursuant to Rule 424(b)(2)	
(To Prospectus dated March 5, 2004, and	 	Registration Statement Nos.	 	333-110499 and	
Prospectus Supplement dated March 5, 2004)	 	 	 	333-110499-01	
 	 	 	 	 	 	 	
	 	 	 	CUSIP: 74254PKF8	

Principal Life Insurance Company
Secured Medium-Term Notes
Issued Through
Principal Life Income Fundings Trust 16 (the “Trust”)
The description of this pricing supplement of the particular terms of the Secured Medium-Term Notes offered hereby, and the Funding Agreement (specified below) issued by Principal Life Insurance Company (“Principal Life”) to the Trust, the payment obligations of which are fully and unconditionally guaranteed by the Guarantee (specified below) issued by Principal Financial Group, Inc. to the Trust, supplements the description of the general terms and provisions of the notes, the funding agreements and the guarantees set forth in the accompanying prospectus and prospectus supplement, to which reference is hereby made. 
1. The Notes

 	 	 	 	 	 	 	 	 	 	 	
Principal Amount:	 	$	75,000,000	 	 	Purchasing Agent(s) Discount:	 	None	 	 	
 	 	 	 	 	 	 	 	 	 	 	
Issue Price:	 	 	100%	 	 	Original Issue Date:	 	December 20, 2005	
 	 	 	 	 	 	 	 	 	 	 	
Net Proceeds to the Trust:	 	$	75,000,000	 	 	Stated Maturity Date:	 	December 19, 2008	

 	 	 	 	 	 	 	 	 	 	 	
Specified Currency:	 	U.S. Dollars	
 	 	 	 	 	 	 	 	 	 	 	
Interest Payment Dates:	 	The nineteenth day of March, June, September and December of each year	
 	 	 	 	 	 	 	 	 	 	 	
Initial Interest Payment Date:	 	March 20, 2006	
 	 	 	 	 	 	 	 	 	 	 	
Regular Record Date:	 	15 calendar days prior to the Interest Payment Date	
 	 	 	 	 	 	 	 	 	 	 	
Type of Interest Rate:	 	o  Fixed Rate	 	þ  Floating Rate	 	 	 	
 	 	 	 	 	 	 	 	 	 	 	
Fixed Rate Notes:	 	o  Yes		þ  No.	 	If, Yes,	
 	 	 	 	 	 	 	 	 	 	 	
Interest Rate:	 	 	 	 	 	 	 	 	 	 	
 	 	 	 	 	 	 	 	 	 	 	
Floating Rate Notes:	 	þ  Yes		o No.	 	If, Yes,	
 	 	 	 	 	 	 	 	 	 	 	
Regular Floating Rate Notes:	 	þ  Yes	 	o  No.	 	If, Yes,	
Interest Rate:	 	3-Month LIBOR + .05%	 	 	 	 	 	 	 	 	
Interest Rate Basis(es):	 	See below.	 	 	 	 	 	 	 	 	
 	 	 	 	 	 	 	 	 	 	 	
Floating Rate/Fixed Rate Note:	 	o  Yes	 	þ  No.	 	If, Yes,	
Floating Interest Rate:	 	 	
Interest Rate Basis(es):	 	 	
Fixed Interest Rate:	 	 	
Fixed Rate Commencement Date:	 	 	

 

 	 	 	 	 	 	 	 	 	 	 	
 	 	 	 	 	 	 	 	 	 	 	
Inverse Floating Rate Note:	 	o  Yes	 	þ  No.	 	If, Yes,	
Fixed Interest Rate:	 	 	
Floating Interest Rate:	 	 	
Interest Rate Basis(es):	 	 	
 	 	 	 	 	 	 	 	 	 	 	
Initial Interest Rate, if any:	 	3-Month Libor + .05% determined on the second London Banking Day preceding the Original Issue Date	
 	 	 	 	 	 	 	 	 	 	 	
Initial Interest Reset Date:	 	March 20, 2006	
 	 	 	 	 	 	 	
Interest Rate Basis(es). Check all that apply:	 	 	 	 	
 	 	o  CD Rate	 	o  Commercial Paper Rate	 	 	
 	 	o  CMT Rate	 	o  Eleventh District Cost of Funds Rate	 	 	
 	 	þ  LIBOR	 	o  Federal Funds Rate	 	 	
 	 	o  EURIBOR	 	o  Treasury Rate	 	 	
 	 	o  Prime Rate	 	o  Other (See Attached)	 	 	
 	 	 	 	 	 	 	
If LIBOR:	 	o  LIBOR Reuters Page	 	þ  LIBOR Moneyline Telerate Page 3750	 	 	
 	 	     LIBOR Currency: U.S. Dollars	 	 	 	 	
 	 	 	 	 	 	 	
If CMT Rate:	 	 	 	 	 	 	
Designated CMT Telerate Page:	 	 	 	 	
If 7052:	 	o  Weekly Average	 	o  Monthly Average	 	 	
Designated CMT Maturity Index:	 	 	 	 	
 	 	 	 	 	 	 	
Index Maturity:	 	3-Month	 	 	 	 	
 	 	 	 	 	 	 	
Spread:	 	+ .05%	 	 	 	 	
 	 	 	 	 	 	 	
Spread Multiplier:	 	Not Applicable	 	 	 	 	
 	 	 	 	 	 	 	
Interest Reset Date(s):	 	Each Interest Payment Date	 	 	 	 	
 	 	 	 	 	 	 	
Interest Rate Determination Date(s):	 	The second London Banking Day preceding the related Interest Reset Date	
 	 	 	 	 	 	 	
Maximum Interest Rate, if any:	 	Not applicable	 	 	 	 	
 	 	 	 	 	 	 	
Minimum Interest Rate, if any:	 	Not applicable	 	 	 	 	
 	 	 	 	 	 	 	
Calculation Agent:	 	Citibank, N.A.	 	 	
 	 	 	 	 	 	 	
Exchange Rate Agent:	 	Not applicable	 	 	
 	 	 	 	 	 	 	
Computation of Interest:	 	 	 	 	 	 	
(not applicable unless different than as specified in the prospectus and prospectus supplement):	
Day Count Convention:	 	 	 	 	 	 	
(not applicable unless different than as specified in the prospectus and prospectus supplement):	
 	 	 	 	 	 	 	
Amortizing Note:	 	o  Yes	 	þ  No.	 	If, Yes,	
Amortizing Schedule:	 	 	 	 	 	 	
Additional/Other Terms:	 	 	 	 	 	 	
 	 	 	 	 	 	 	
Discount Note:	 	o  Yes	 	þ  No.	 	If, Yes,	
Total Amount of Discount:	 	 	 	 	 	 	
Initial Accrual Period of Discount:	 	 	 	 	 	 	
Additional/Other Terms:	 	 	 	 	 	 	
 	 	 	 	 	 	 	
Redemption Provisions:	 	o  Yes	 	þ  No.	 	If, Yes,	
Initial Redemption Date:	 	 	 	 	 	 	
Initial Redemption Percentage:	 	 	 	 	 	 	
Annual Redemption Percentage Reduction (if any):	 	 	 	 	 	 	
Redemption:	 	o  In whole only and not in part	 	 	
	 	o  May be in whole or in part	 	 	
Additional Other Terms:	 	 	 	 	 	 	

 

 	 	 	 	 	 	 	
Repayment:	 	o  Yes	 	þ  No.	 	If, Yes,	
Repayment Date(s):	 	 	 	 	 	 	
Repayment Price:	 	 	 	 	 	 	
Repayment:	 	o  In whole only and not in part	 	 	
	 	o  May be in whole or in part	 	 	
Additional/Other Terms:	 	 	 	 	 	 	
 	 	 	 	 	 	 	
Sinking Fund (not applicable unless specified):	 	
 	 	 	 	 	 	 	
Additional Amounts to be Paid for Withholding Tax (not applicable unless specified):	
 	 	 	 	 	 	 	
Securities Exchange Listing:	 	o  Yes	 	þ  No.	 	If, Yes, Name of Exchange:	
 	 	 	 	 	 	 	
Authorized Denominations:	 	$100,000 and integral multiplies of $1,000	
Ratings:
The Notes issued under the Program are rated AA by Standard & Poor’s Ratings Services, a division of The McGraw-Hill Companies, Inc. (“S&P”).
Principal Life expects the Notes to be rated Aa2 by Moody’s Investors Service, Inc. (“Moody’s”).
 	 	 	 	 	 	 	
Purchasing Agents Acting as Agent:	 	þ Yes	 	o No.	 	If, Yes:	
 	 	 	 	 	
Purchasing Agent(s)
	 	Principal Amount
	
Goldman, Sachs & Co.	 	$	75,000,000	 	

Total:	 	$	75,000,000	 	
 	 	 	 	 	 	 	
Purchasing Agents Acting as Agent:	 	o Yes	 	þ No.	 	If, Yes:	
 	 	 	 	 	
 Purchasing Agent(s)
	 	Principal Amount

 	
Total:	 	 	                            	 	
 	 	 	 	 	 	 	 	 	 	 	
State of Organization of the Trust:	New York	 	 	 	 	 	 	 	 	
 	 	 	 	 	 	 	 	 	 	 	
Additional/Other Terms:	Not applicable	

Special Tax Considerations:	Interest payable on the Notes will be treated as “qualified stated interest” for United States federal income tax purposes, as it meets the specified criteria referenced in the prospectus supplement under the heading “Material United States Federal Income Tax Considerations—U.S. Holders— Interest and Original Issue Discount” .	
 	 	 	 	 	 	 	 	 	 	 	
2. The Funding Agreement	 	 	 	 	 	 	 	 	 	
 	 	 	 	 	 	 	 	 	 	 	
Funding Agreement Issuer:	Principal Life Insurance Company	 	 	 	 	 	 	
 	 	 	 	 	 	 	 	 	 	 	
Funding Agreement No.:	6-12923	 	 	 	 	 	 	 	 	
 	 	 	 	 	 	 	 	 	 	 	
Deposit:	 	$75,000,015	
 	 	 	 	 	 	 	 	 	 	 	
Net Deposit:	$75,000,000	
 	 	 	 	 	 	 	 	 	 	 	
Effective Date:	December 20, 2005	
 	 	 	 	 	 	 	 	 	 	 	
Stated Maturity Date:	December 19, 2008	
 	 	 	 	 	 	 	 	 	 	 	
Specified Currency:	 	U.S. Dollars	

 

 	 	 	 	 	 	 	 	 	 	 	
 	 	 	 	 	 	 	 	 	 	 	
Interest Payment Dates:	 	The nineteenth day of March, June, September and December of each year	
 	 	 	 	 	 	 	 	 	 	 	
Initial Interest Payment Date:	 	March 20, 2006	
 	 	 	 	 	 	 	 	 	 	 	
Type of Interest Rate:	 	o  Fixed Rate	 	þ  Floating Rate	 	 	 	
 	 	 	 	 	 	 	 	 	 	 	
Fixed Rate Funding Agreement:	 	o  Yes		þ  No.	 	If, Yes,	
 	 	 	 	 	 	 	 	 	 	 	
Interest Rate:	 		
 	 	 	 	 	 	 	 	 	 	 	
Floating Rate Funding Agreement:	 	þ  Yes		o No.	 	If, Yes,	
 	 	 	 	 	 	 	 	 	 	 	
Regular Floating Rate Funding	 	   	 	   	 	 	
Agreement:	 	þ  Yes	 	o  No.	 	If, Yes,	
Interest Rate:	 	3-Month LIBOR + .05%	 	 	 	 	 	 	 	 	
Interest Rate Basis(es):	 	See below	
 	 	 	 	 	 	 	 	 	 	 	
Floating Rate/Fixed Rate Funding	 	   	 	   	 	 	
Agreement:	 	o  Yes	 	þ  No.	 	If, Yes,	
Floating Interest Rate:	 	 	
Interest Rate Basis(es):	 	 	
Fixed Interest Rate:	 	 	 	 	
Fixed Rate Commencement Date:	 	 	
 	 	 	 	 	 	 	 	 	 	 	
Inverse Floating Rate Funding	 	   	 	   	 	 	
Agreement:	 	o  Yes	 	þ  No.	 	If, Yes,	
Fixed Interest Rate:	 	 	
Floating Interest Rate:	 	 	
Interest Rate Basis(es):	 	 	
 	 	 	 	 	 	 	 	 	 	 	
Initial Interest Rate, if any:	 	3-Month Libor + .05% determined on the second London Banking Day preceding the Original Issue Date	
 	 	 	 	 	 	 	 	 	 	 	
Initial Interest Reset Date:	 	March 20, 2006	
 	 	 	 	 	 	 	
Interest Rate Basis(es). Check all that apply:	 	 	 	 	
 	 	o  CD Rate	 	o  Commercial Paper Rate	 	 	
 	 	o  CMT Rate	 	o  Eleventh District Cost of Funds Rate	 	 	
 	 	þ  LIBOR	 	o  Federal Funds Rate	 	 	
 	 	o  EURIBOR	 	o  Treasury Rate	 	 	
 	 	o  Prime Rate	 	o  Other (See Attached)	 	 	
 	 	 	 	 	 	 	
If LIBOR:	 	o  LIBOR Reuters Page	 	þ  LIBOR Moneyline Telerate Page 3750	 	 	
 	 	     LIBOR Currency:	U.S. Dollars	 	 	 	
 	 	 	 	 	 	 	
If CMT Rate:	 	 	 	 	 	 	
Designated CMT Telerate Page:	 	 	 	 	
If 7052:	 	o  Weekly Average	 	o  Monthly Average	 	 	
Designated CMT Maturity Index:	 	 	 	 	
 	 	 	 	 	 	 	
Index Maturity:	 	3-Month	
 	 	 	 	 	 	 	
Spread:	 	+.05%	
 	 	 	 	 	 	 	
Spread Multiplier:	 	Not Applicable	
 	 	 	 	 	 	 	
Interest Reset Date(s):	 	Each Interest Payment Date	
 	 	 	 	 	 	 	
Interest Rate Determination Date(s):	 	The second London Banking Day preceding the related Interest Reset Date	
 	 	 	 	 	 	 	
Maximum Interest Rate, if any:	 	Not applicable	
 	 	 	 	 	 	 	
Minimum Interest Rate, if any:	 	Not applicable	
 	 	 	 	 	 	 	
Computation of Interest:	 	 	
(not applicable unless different than as specified in the prospectus and prospectus supplement):	
Day Count Convention:	 	 	 	 	 	 	
(not applicable unless different than as specified in the prospectus and prospectus supplement):	

 

 	 	 	 	 	 	 	
Amortizing Funding Agreement:	 	o Yes	 	þ  No.	 	If, Yes,	
Amortizing Schedule:	 	 	 	 	 	 	
Additional/Other Terms:	 	 	 	 	 	 	
 	 	 	 	 	 	 	
Discount Funding Agreement:	 	o Yes	 	þ  No.	 	If, Yes,	
Total Amount of Discount:	 	 	 	 	 	 	
Initial Accrual Period of Discount:	 	 	 	 	 	 	
Additional/Other Terms:	 	 	 	 	 	 	
 	 	 	 	 	 	 	
Redemption Provisions:	 	o Yes	 	þ  No.	 	If, Yes,	
Initial Redemption Date:	 	 	 	 	 	 	
Initial Redemption Percentage:	 	 	 	 	 	 	
Annual Redemption Percentage Reduction (if any):	 	 	 	
Redemption:	 	o In whole only and not in part	 	 	
	 	o May be in whole or in part	 	 	
Additional/Other Terms:	 	 	 	 	 	 	
 	 	 	 	 	 	 	
Repayment:	 	o Yes	 	þ  No.	 	If, Yes,	
Repayment Date(s):	 	 	 	 	 	 	
Repayment Price:	 	 	 	 	 	 	
Repayment:	 	o In whole only and not in part	 	 	
	 	o May be in whole or in part	 	 	
Additional/Other Terms:	 	 	 	 	 	 	
 	 	 	 	 	 	 	
Sinking Fund (not applicable unless specified):	 	
 	 	 	 	 	 	 	
Additional Amounts to be Paid For Withholding Tax (not applicable unless specified):	
Ratings:
The Funding Agreement issued under the Program is rated AA by S&P.
Principal Life expects the Funding Agreement to be rated Aa2 by Moody’s.
 	 	 	
Additional/Other Terms:	 	Not applicable	
 	 	 	
Special Tax Considerations:	 	Not applicable	
 	 	 	
3. The Guarantee	 	 	
 	 	 	
Guarantee Issuer:	 	Principal Financial Group, Inc.	
 	 	 	
Effective Date:	 	December 20, 2005	
 	 	 	
Additional/Other Terms:	 	Not applicable