SUPPLEMENT DATED AUGUST 19, 2013

to

STATEMENTS OF ADDITIONAL INFORMATION DATED APRIL 29, 2013

FOR SUN LIFE FINANCIAL MASTERS CHOICE, SUN LIFE FINANCIAL MASTERS FLEX,

SUN LIFE FINANCIAL MASTERS EXTRA, SUN LIFE FINANCIAL MASTERS CHOICE II,

SUN LIFE FINANCIAL MASTERS FLEX II, MFS REGATTA PLATINUM,

AND MFS REGATTA GOLD

ISSUED BY SUN LIFE ASSURANCE COMPANY OF CANADA (U.S.)

SUN LIFE OF CANADA (U.S.) VARIABLE ACCOUNT F

The text under the heading “Sun Life Assurance Company of Canada (U.S.)” in the Statement of Additional Information is replaced with the following:

Effective August 2, 2013, the parent of Sun Life Assurance Company of Canada (U.S.) is Delaware Life Holdings, LLC (“Delaware Life”).  Delaware Life is a limited liability company formed under the laws of Delaware on December 12, 2012.  Delaware Life is ultimately controlled by Todd L. Boehly and Mark R. Walter.  Messrs. Boehly and Walter ultimately control the Company through the following intervening companies:  Delaware Life, Delaware Life Holdings Parent, LLC, Delaware Life Holdings Parent II, LLC, Delaware Life Equity Investors, LLC, DLICM, LLC and DLICT, LLC.  The nature of the business of Messrs. Boehly and Walter and these intervening companies is investing in companies engaged in the business of life insurance and annuities.

THIS SUPPLEMENT SHOULD BE READ AND RETAINED FOR FUTURE REFERENCE.

Variable Account F SAIs (US)                                                                                                                                          8/2013