X0101 EFFECT 33 LIVE 2015-11-02 0000009713-15-000122 485APOS 0000009713 PRINCIPAL LIFE INSURANCE CO SEPARATE ACCOUNT B 333-188293 S000001542 PRINCIPAL LIFE INSURANCE CO SEPARATE ACCOUNT B C000129044 Principal Investment Plus Variable Annuity (Applications Signed On or After 08/01/2013)