REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM


To the Board of Trustees of MFS Variable Insurance Trust III (formerly Sun
Capital Advisers Trust) and the Shareholders of MFS Blended Research Small Cap
Equity Portfolio (formerly SC BlackRock Small Cap Index Fund), MFS Conservative
Allocation Portfolio (formerly SC Ibbotson Conservative Fund), MFS Global Real
Estate Portfolio (formerly Sun Capital Global Real Estate Fund), MFS Growth
Allocation Portfolio (formerly SC Ibbotson Growth Fund), MFS Inflation-Adjusted
Bond Portfolio (formerly SC BlackRock Inflation Protected Bond Fund), MFS
Limited Maturity Portfolio (formerly SC Goldman Sachs Short Duration Fund), MFS
Mid Cap Value Portfolio (formerly SC Goldman Sachs Mid Cap Value Fund), MFS
Moderate Allocation Portfolio (formerly SC Ibbotson Balanced Fund), and MFS New
Discovery Value Portfolio (formerly SC Columbia Small Cap Value Fund)
(collectively, the "Funds"):


In planning and performing our audits of the financial statements of the Funds
as of and for the year ended December 31, 2012, in accordance with the standards
of the Public Company Accounting Oversight Board (United States), we considered
the Funds' internal control over financial reporting, including controls over
safeguarding securities, as a basis for designing our auditing procedures for
the purpose of expressing our opinion on the financial statements and to comply
with the requirements of Form N-SAR, but not for the purpose of expressing an
opinion on the effectiveness of the Funds' internal control over financial
reporting.  Accordingly, we express no such opinion.


The management of the Funds is responsible for establishing and maintaining
effective internal control over financial reporting.  In fulfilling this
responsibility, estimates and judgments by management are required to assess the
expected benefits and related costs of controls.  A fund's internal control over
financial reporting is a process designed to provide reasonable assurance
regarding the reliability of financial reporting and the preparation of
financial statements for external purposes in accordance with generally accepted
accounting principles.  A fund's internal control over financial reporting
includes those policies and procedures that (1) pertain to the maintenance of
records that, in reasonable detail, accurately and fairly reflect the
transactions and dispositions of the assets of the fund; (2) provide reasonable
assurance that transactions are recorded as necessary to permit preparation of
financial statements in accordance with generally accepted accounting
principles, and that receipts and expenditures of the fund are being made only
in accordance with authorizations of management and trustees of the fund; and
(3) provide reasonable assurance regarding prevention or timely detection of
unauthorized acquisition, use, or disposition of a fund's assets that could have
a material effect on the financial statements.


Because of its inherent limitations, internal control over financial reporting
may not prevent or detect misstatements.  Also, projections of any evaluation of
effectiveness to future periods are subject to the risk that controls may become
inadequate because of changes in conditions or that the degree of compliance
with the policies or procedures may deteriorate.


A deficiency in internal control over financial reporting exists when the design
or operation of a control does not allow management or employees, in the normal
course of performing their assigned functions, to prevent or detect
misstatements on a timely basis.  A material weakness is a deficiency, or a
combination of deficiencies, in internal control over financial reporting, such
that there is a reasonable possibility that a material misstatement of the
funds' annual or interim financial statements will not be prevented or detected
on a timely basis.


Our consideration of the Funds' internal control over financial reporting was
for the limited purpose described in the first paragraph and would not
necessarily disclose all deficiencies in internal control that might be material
weaknesses under standards established by the Public Company Accounting
Oversight Board (placecountry-regionUnited States).  However, we noted no
deficiencies in the Funds' internal control over financial reporting and their
operation, including controls for safeguarding securities, that we consider to
be a material weakness, as defined above, as of December 31, 2012.


This report is intended solely for the information and use of management and the
Board of Trustees of MFS Variable Insurance Trust III and the Securities and
Exchange Commission and is not intended to be and should not be used by anyone
other than these specified parties.

DELOITTE & TOUCHE LLP

Boston, Massachusetts
February 15, 2013