| SUPPLEMENT DATED DECEMBER 17, 2012 |
| TO THE PROSPECTUS FOR |
| PRINCIPAL VARIABLE UNIVERSAL LIFE INCOME III |
| DATED MAY 1, 2012 |
| This supplement updates information in the prospectus dated May 1, 2012, for the variable life insurance |
| policy referenced above (the “Policy”), which is issued by Principal National Life Insurance Company. |
| This supplement should be read in its entirety and kept together with your prospectus for future reference. |
| Certain terms used in this supplement have special meanings. If a term is not defined in this supplement, |
| it has the meaning given to it in the prospectus. |
| TABLE OF SEPARATE ACCOUNT DIVISIONS |
| AllianceBernstein Small Cap Growth Division |
| Effective after February 1, 2013, this division will be closed as an investment option to Policy owners who |
| purchase their Policy after that date. If you are an existing Policy owner as of that date, you may continue |
| to allocate policy value to this division in accordance with your Policy’s prospectus. |