PRINCIPAL LIFE INSURANCE COMPANY SEPARATE ACCOUNT B

Supplement dated February 9, 2018 to the following Statutory Prospectuses:

Principal Investment Plus Variable Annuity^SM (for applications signed on or after August 1, 2013)

Dated May 1, 2017, as supplemented May 2, 2017, May 12, 2017, November 7, 2017 and January 16, 2018

Principal Investment Plus Variable Annuity^SM (for applications signed before August 1, 2013)

Dated May 1, 2017, as supplemented May 2, 2017, November 7, 2017 and January 16, 2018

Principal Pivot Series Variable Annuity^SM 

Dated May 1, 2017, as supplemented September 22, 2017 and January 16, 2018

Principal Flexible Variable Annuity

Dated May 1, 2017, as supplemented May 2, 2017, November 7, 2017 and January 16, 2018

This supplement updates information contained in the Statutory Prospectus for the variable annuity insurance contracts referenced above. Please retain this supplement for future reference.

LIQUIDATION OF THE BLACKROCK ISHARES^® DYNAMIC FIXED INCOME V.I. FUND AND THE BLACKROCK ISHARES^® EQUITY APPRECIATION V.I. FUND

Two of the underlying mutual funds available as investment options under the variable annuity contracts referenced above are liquidating on or about March 29, 2018. In a supplement dated January 16, 2018, we advised you of the liquidation of the underlying mutual funds that are investment options under your contract. The purpose of this supplement is to modify certain dates and information regarding the transaction.

Principal Life Insurance Company (“Principal”) has been informed by BlackRock Advisors, LLC, that the BlackRock iShares^® Dynamic Fixed Income V.I. Fund and BlackRock iShares^® Equity Appreciation V.I. Fund (each, a “Liquidating Fund” and together, the “ Liquidating Funds”), each a series of the BlackRock Variable Insurance Funds - Class III (the Liquidating Separate Account Division) were approved for liquidation by the Board of Directors effective on or about March 29, 2018, (the “Liquidation Date”). As such, no transfers into the Liquidating Funds will be allowed on or after March 16, 2018. The Liquidating Funds will no longer be available as an investment option on or after March 16, 2018, and any request for transfer into the Liquidating Funds received on or after March 16, 2018, or any remaining values you have in the Liquidating Funds will be transferred into the Fidelity VIP Government Money Market Fund, unless we receive a request from you to transfer your funds into a different fund.

TABLE OF SEPARATE ACCOUNT DIVISIONS

On or about March 16, 2018, replace the BlackRock iShares Dynamic Fixed Income Division row and the BlackRock iShares Equity Appreciation Division row with the following:

BlackRock iShares Dynamic Fixed Income Division (no longer available to new investors with an application signature dated on or after March 16, 2018)

BlackRock iShares Equity Appreciation Division (no longer available to new investors with an application signature dated on or after March 16, 2018)

On or about March 16, 2018, delete the sections for BlackRock iShares Dynamic Fixed Income Division and BlackRock iShares Equity Appreciation Division.