SCHEDULE 14A INFORMATION
          PROXY STATEMENT PURSUANT TO SECTION 14(A) OF THE SECURITIES
                              EXCHANGE ACT OF 1934

FILED BY THE REGISTRANT [X]                     FILED BY A PARTY OTHER
                                                THAN THE REGISTRANT [ ]

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CHECK THE APPROPRIATE BOX:
[ ] Preliminary Proxy Statement
[ ] Confidential for Use of the Commission Only (as permitted
    by Rule 14a-6(e)(2))
[X] Definitive Proxy Statement
[ ] Definitive Additional Materials
[ ] Soliciting Material Pursuant to sec. 240.14a-11(c) or sec. 240.14a-12

                               MFS Series Trust I
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                (Name of Registrant as Specified in its Charter)

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    (Name of Person(s) Filing Proxy Statement, if other than the Registrant)

PAYMENT OF FILING FEE (CHECK THE APPROPRIATE BOX):
   [X] No fee required.
   [ ] Fee computed on table below per Exchange Act Rules 14a-6(i)(4) and 0-11.

       1) Title of each class of securities to which transaction applies:

       2) Aggregate number of securities to which transaction applies:

       3) Per unit price or other underlying value of transaction computed
          pursuant to Exchange Act Rule 0-11 (Set forth the amount on which the
          filing fee is calculated and state how it was determined):

       4) Proposed maximum aggregate value of transaction:

       5) Total Fee Paid:

   [ ] Fee paid previously with preliminary materials.

   [ ] Check box if any part of the fee is offset as provided by Exchange Act
       Rule 0-11(a)(2) and identify the filing for which the offsetting fee was
       paid previously. Identify the previous filing by registration statement
       number, or the Form or Schedule and the date of its filing.

       1) Amount previously paid:

       2) Form, Schedule or Registration Statement No.:

       3) Filing Party:

       4) Date Filed:

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                   Massachusetts Financial Services Company
                             500 Boylston Street
                            Boston, MA 02116-3741

                                                                 June 12, 2006

Dear Shareholder:

    A Special Meeting of Shareholders ("Shareholders" Meeting") of the MFS(R)
Technology Fund (the "Fund"), a series of MFS(R) Series Trust I (the "Trust"),
will be held at the offices of the Trust, 500 Boylston Street, 24th Floor,
Boston, Massachusetts, on August 15, 2006 at 9:30 a.m., Eastern time.

    You are being asked to vote on two proposals affecting the Fund. The first
is  a  proposal to approve a change to the Fund's sub-classification under the
Investment  Company  Act  of  1940  from  a  "diversified  company" to a "non-
diversified company." The second is a proposal to amend the Fund's fundamental
investment policy concerning concentration.

    While  you are, of course, welcome to join us at the Shareholders' Meeting
on August 15, 2006, most shareholders vote by telephone, over the Internet, or
by filling out, signing, and returning the enclosed proxy card.

    Your  vote makes a difference. No matter what the size of your investment,
your  vote  is important. The Trustees of the Fund recommend that you vote for
these proposals, but however you decide to vote, it is important that you take
the  time to do so. By voting early, you can help save the Fund the expense of
additional mailings to solicit shareholder votes.

    Information  regarding  the proposals is available in the proxy statement.
There  are  three convenient ways to vote: by telephone, over the Internet, or
by  filling  out,  signing  and  returning  the  enclosed  proxy  card. Voting
instructions are provided on the proxy card.


    If  you  have  any questions, please contact your investment professional.
For  questions  regarding the proposals, please call the proxy solicitor, ADP/
Management Information Services Corporation, toll-free at 1 (877) 333-2372.


    Thank you for your prompt vote.

                                        Sincerely,

                                        /s/ MARIA F. DWYER

                                        Maria F. Dwyer
                                        President
                                        MFS(R) Family of Funds




                            MFS(R) TECHNOLOGY FUND
               500 BOYLSTON STREET, BOSTON, MASSACHUSETTS 02116


                 NOTICE OF A SPECIAL MEETING OF SHAREHOLDERS
                        TO BE HELD ON AUGUST 15, 2006


A Special Meeting of Shareholders of MFS Technology Fund (the "Fund"), a series
of MFS Series Trust I, will be held at 500 Boylston Street, Boston,
Massachusetts 02116, at 9:30 a.m., Eastern time, on Tuesday, August 15, 2006,
for the following purposes:


    ITEM 1. To  approve  a  change  to the Fund's sub-classification under the
            Investment  Company  Act  of  1940 from a diversified company to a
            non-diversified company.

    ITEM 2. To  approve  an  amendment  to  the  Fund's fundamental investment
            policy concerning concentration.

    ITEM 3. To  transact  such  other business as may properly come before the
            Meeting and any adjournments thereof.


                     THE TRUSTEES OF THE TRUST RECOMMEND
                     THAT YOU VOTE IN FAVOR OF ALL ITEMS.


Only  the  Fund's  shareholders  of record on June 5, 2006 will be entitled to
vote at the Fund's Meeting of Shareholders.

                                        By order of the Board of Trustees
                                        Susan S. Newton
                                        Assistant   Secretary   and  Assistant
                                        Clerk

June 12, 2006


YOUR  VOTE IS IMPORTANT. WE WOULD APPRECIATE YOUR PROMPTLY VOTING, SIGNING AND
RETURNING THE ENCLOSED PROXY SO THAT IT IS RECEIVED BY THE DATE OF THE SPECIAL
MEETING OR RECORDING YOUR VOTING INSTRUCTIONS BY TELEPHONE OR VIA THE INTERNET
BY  9:29  A.M.,  EASTERN  TIME, ON THE DATE OF THE SPECIAL MEETING, WHICH WILL
HELP  AVOID THE ADDITIONAL EXPENSE OF A SECOND SOLICITATION FOR YOUR FUND. THE
ENCLOSED  ADDRESSED  ENVELOPE  REQUIRES  NO  POSTAGE  AND IS PROVIDED FOR YOUR
CONVENIENCE.



                            MFS(R) TECHNOLOGY FUND

                               Proxy Statement
                                June 12, 2006


    This  Proxy  Statement is furnished in connection with the solicitation of
proxies  by and on behalf of the Board of Trustees (the "Board") of MFS Series
Trust  I  (the  "Trust")  to  be  used  at  the  Meeting  of Shareholders (the
"Meeting")  of the MFS(R) Technology Fund (the "Fund"), a series of the Trust,
to  be  held  at  9:30  a.m.,  Eastern time on August 15, 2006 at 500 Boylston
Street,  Boston,  Massachusetts  02116,  for  the  purposes  set  forth in the
accompanying  Notice  of  a Special Meeting of Shareholders (the "Notice"). If
the  enclosed  form  of proxy is executed and returned, it nevertheless may be
revoked  prior  to  its  exercise  by  a  signed  writing filed with the proxy
tabulation  agent, ADP/Management Information Services Corporation ("MIS"), 60
Research Road, Hingham, Massachusetts 02043, or delivered at the Meeting.

    On  June  5,  2006,  the number of outstanding shares of each Class of the
Fund  and  the  number  of  votes that each Class was entitled to vote were as
follows:





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MFS TECHNOLOGY FUND                              CLASS A           CLASS B           CLASS C           CLASS I          CLASS R
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Shares outstanding                              4,717,683.337     4,279,452.027     1,271,563.402      333,341.591      301,107.489
Number of votes that class is entitled to
 vote (net asset value X number of shares
 outstanding)                                   46,563,534.54     40,654,794.26     12,054,421.05     3,373,416.90     2,950,853.39
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                                                 CLASS R1          CLASS R2          CLASS R3         CLASS R4         CLASS R5
- -----------------------------------------------------------------------------------------------------------------------------------
Shares outstanding                                 21,949.647        39,540.743        77,724.932       36,445.916        6,053.269
Number of votes that class is entitled to
 vote (net asset value X number of shares
 outstanding)                                      208,302.15        376,823.28        757,818.09       359,721.19        59,927.36
- -----------------------------------------------------------------------------------------------------------------------------------


    Shareholders  of  record  at the close of business on June 5, 2006 will be
entitled  to  one  vote  for each dollar of net asset value held on that date.
Each fractional dollar amount is entitled to a proportionate fractional vote.

    Shareholders  have the opportunity to submit their voting instructions via
the  Internet  by using a program provided by a third-party vendor retained by
the  Fund,  by automated telephone service or by mail using the enclosed proxy
card.  Internet  and  telephone  voting  is available until 9:29 a.m., Eastern
time, on August 15, 2006.

    The  mailing  address of the Trust and of the Fund is 500 Boylston Street,
Boston,  Massachusetts  02116.  Solicitation  of  proxies is being made by the
mailing of the Notice and this Proxy Statement with its enclosures on or about
June  12, 2006. In addition to soliciting proxies by mail, the Trustees of the
Trust  and  employees of Massachusetts Financial Services Company ("MFS"), the
Fund's  investment adviser and administrator, may solicit proxies in person or
by  telephone.  At  its  own expense, the Fund has retained ADP, to aid in the
solicitation  of  instructions  for registered and nominee accounts, for a fee
expected  not  to  exceed  $12,500  plus reasonable out-of-pocket expenses for
mailing.  The  expenses  of the preparation of the proxy statement and related
materials, including printing and delivery costs, are borne by the Fund.

    A  copy of the Fund's most recent annual report and semi-annual report may
be  obtained without charge by contacting MFS Service Center, Inc., the Fund's
transfer  and  shareholder  servicing  agent,  at 500 Boylston Street, Boston,
Massachusetts 02116, or by telephoning toll-free (800) 225-2606.


ITEM 1 -- PROPOSAL TO CHANGE THE FUND'S SUBCLASSIFICATION

    The  Board  has  approved,  and  recommends  that shareholders of the Fund
approve,  changing the Fund from a "diversified company" to a "non-diversified
company."  As  a  "diversified  company"  under Section 5(b) of the Investment
Company  Act  of  1940 Act, as amended (the "1940 Act"), the Fund must have at
least  75%  of the value of its total assets in cash and cash items (including
receivables), government securities, securities of other investment companies,
and  other  securities (the "75% basket"). For purposes of the 75% basket, the
Fund may not count securities of a single issuer that account for more than 5%
of  the  Fund's total assets or that constitute more than 10% of such issuer's
outstanding  voting  securities as "other securities." As to the remaining 25%
of the Fund's total assets, there is no limitation on the amount of assets the
Fund may invest in a single issuer.

    For  example, currently, if the Fund seeks to make an investment that will
cause  its ownership of an issuer to constitute 6% of the Fund's total assets,
because  the  Fund  is a "diversified company" that position would be excluded
from  the  75%  basket.  In addition, if the Fund's acquisition of an issuer's
shares causes the Fund to hold more than 10% of an issuer's outstanding voting
securities, that position would likewise be excluded from the 75% basket. This
restriction  is  designed  to  prevent  funds  that  hold  themselves  out  as
diversified  from  being  tied  too  closely  to  the  success of one or a few
issuers.  In  addition, the restriction is designed to prevent such funds from
controlling portfolio companies.

    Conversely,  the  1940 Act places no limits on a "non-diversified company"
in this regard.


    The Fund's sub-classification as a "diversified company" cannot be changed
without  shareholder  approval. If shareholders approve the Proposal, the Fund
will  no  longer  be  required  to  comply  with the diversification standards
outlined above. As a result, the Fund will be permitted to invest a relatively
large  percentage  of  its  assets  in  a  single  issuer or a small number of
issuers. MFS has advised the Board that changing the Fund's sub-classification
to   "non-diversified"  would  allow  the  Fund's  portfolio  manager  greater
flexibility  in  pursuing  the  Fund's investment objective. MFS believes that
there  are  a  number  of  technology companies that present opportunities for
growth.  If the Fund is "non-diversified," the portfolio manager will have the
flexibility  to  make  larger investments in technology companies he considers
attractive.  While  investing  a  larger  portion  of the Fund's assets in the
stocks  of  fewer  technology  companies may prove beneficial when such stocks
outperform  the  market,  larger investments in the stocks of fewer technology
companies  will also magnify any negative or under-performance by such stocks.
In general, because the Fund's performance may become more closely tied to the
value  of  a  single  issuer  or a small number of issuers, it may become more
volatile than the performance of more diversified funds. However, MFS believes
these   additional   risks  are  outweighed  by  the  potential  for  improved
performance.


    Approval   of  this  proposal  will  not  affect  the  Fund's  ability  or
requirement  to  comply with the diversification and other requirements of the
Internal  Revenue  Code  of  1986,  as  amended  (the  "Code"),  applicable to
regulated  investment  companies  so that the Fund will not be subject to U.S.
federal  income  taxes  on  its  net  investment  income.  In this regard, the
applicable  diversification  requirements imposed by the Code provide that the
Fund  must  diversify  its  holdings so that at the end of each quarter of the
Fund's  taxable  year (i) at least 50% of the market value of the Fund's total
assets  is represented by cash and cash items, U.S. government securities, the
securities  of other regulated investment companies and other securities, with
such  other  securities  of  any  one  issuer  limited  for  purposes  of this
calculation  to an amount not greater than 5% of the value of the Fund's total
assets  and  not  more  than  10% of the outstanding voting securities of such
issuer,  and (ii) not more than 25% of the value of the Fund's total assets is
invested  in  (x)  the  securities of any one issuer or of two or more issuers
which the Fund controls and which are engaged in the same, similar, or related
trades  or businesses (other than U.S. government securities or the securities
of  other  regulated  investment companies) or (y) in the securities of one or
more publicly traded partnerships.

REQUIRED VOTE
    Approval  of  this  matter will require the vote of (i) 67% or more of the
outstanding  voting  securities  of  the  Fund  present at the Meeting, if the
holders  of more than 50% of the outstanding voting securities of the Fund are
present  or  represented  by  proxy  or  (ii) more than 50% of the outstanding
voting securities of the Fund, whichever is less.

    THE  TRUSTEES  OF THE TRUST UNANIMOUSLY RECOMMEND THAT THE SHAREHOLDERS OF
THE FUND VOTE TO APPROVE THIS PROPOSAL.

ITEM 2   --  PROPOSAL  TO  AMEND  THE  FUND'S  FUNDAMENTAL  INVESTMENT  POLICY
             CONCERNING CONCENTRATION

    The  Board  has  approved,  and  recommends  that shareholders of the Fund
approve,  an amendment to the Fund's concentration policy. Under the 1940 Act,
a  fund must recite any policy to concentrate its investments in securities of
issuers  in  a  particular  industry  or  group  of  industries  in the fund's
prospectus. Any change to this policy requires shareholder approval. While the
1940  Act does not define what constitutes "concentration" in an industry, the
staff  of  the  Securities  and  Exchange  Commission  takes the position that
investment of more than 25% of a fund's assets in any one industry or group of
industries  constitutes  concentration. If a fund concentrates in a particular
industry  or  group  of  industries,  it must have more than 25% of its assets
invested  in  that  industry  or group of industries. The Fund currently has a
fundamental  investment  policy  not  to  concentrate  its  investments  in  a
particular industry.

    Under  normal  market conditions, the Fund invests at least 80% of its net
assets  in  common  stocks  and  related  securities, such as preferred stock,
convertible securities and depositary receipts, of companies that MFS believes
have  above  average  growth  potential  and  will  benefit from technological
advances  and  improvements (the Fund's "name policy"). These companies are in
such  fields as computer software and hardware, semiconductors, minicomputers,
peripheral     equipment,    scientific    instruments,    telecommunications,
pharmaceuticals,   environmental  services,  chemicals,  synthetic  materials,
defense and commercial electronics, data storage and retrieval, biotechnology,
and health care and medical supplies.

    The  Fund's current fundamental investment policy with respect to industry
concentration states:

        "The  Fund  may  not purchase any securities of an issuer in a
        particular  industry  if  as a result 25% or more of its total
        assets  (taken  at market value at the time of purchase) would
        be  invested in securities of issuers whose principal business
        activities are in the same industry."

    The  proposed  fundamental  investment  policy  with  respect  to industry
concentration that you are asked to approve states:

        "The  Fund  may  not purchase any securities of an issuer in a
        particular  industry  if  as a result 25% or more of its total
        assets  (taken  at market value at the time of purchase) would
        be  invested in securities of issuers whose principal business
        activities  are  in  the same industry, provided however, that
        the  Fund  will invest at least 25% of its total assets in the
        securities  of issuers principally engaged in offering, using,
        or  developing  products,  processes,  or  services  that will
        provide  or  will  benefit  significantly  from  technological
        advances and improvements."

    For  purposes  of  this  policy, MFS considers an issuer to be principally
engaged  in  offering,  using,  or developing products, processes, or services
that  will  provide  or will benefit significantly from technological advances
and improvements if (i) at least 50% of any issuer's assets, income, sales, or
profits  are  committed  to, or derived from, such activities, or (ii) a third
party  has  given  the  issuer an industry or sector classification consistent
with such activities.

    The  change  in  concentration policy is intended to provide the portfolio
manager  of  your Fund with additional flexibility in selecting investments in
companies,  fields and industries that MFS considers to be principally engaged
in  offering,  using  or  developing products, processes or services that will
provide  or benefit significantly from technological advances and improvements
("technology  companies").  MFS  believes that there are a number of companies
engaged in these activities that present opportunities for growth. If the Fund
is  permitted  to  concentrate  its  assets  in  technology companies within a
particular  industry,  MFS  believes that the portfolio manager may be able to
take advantage of investment opportunities that would otherwise be prohibited.

    As  noted  above,  under normal circumstances, the Fund already invests at
least  80%  of its net assets in common stocks and related securities that MFS
believes  will benefit from technological advances and improvements. Thus, the
Fund's  performance  currently  is,  and  will  continue  to  be,  tied to the
performance  of  issuers  in  a  limited number of industries, which may react
similarly   to  market,  economic,  political  or  regulatory  conditions  and
developments. If shareholders approve the Proposal, the Fund will be permitted
to  invest a relatively large percentage of its assets in technology companies
within a single industry (e.g., electronics). While investing a larger portion
of  the  Fund's  assets  in  the  stocks  of  technology companies in a single
industry  may  prove  beneficial  when  stocks in that industry outperform the
market,  larger  investments  in stocks in a single industry will also magnify
any  negative  or  under-performance  by  such stocks. As a result, the fund's
performance  could  be  more  volatile  than  the  performance of more broadly
diversified funds. However, MFS believes these additional risks are outweighed
by  the potential for improved performance. The price of technology stocks can
also  be  very volatile, especially over the short-term, due to the rapid pace
of  product  change  and technological developments. Issuers doing business in
the  technology area are subject to significant competitive pressures, such as
new  market  entrants,  short product cycles, competition for market share and
falling prices and profits. Issuers doing business in the technology area also
face  the  risk  that  new  services,  equipment  or  technologies will not be
commercially successful or will rapidly become obsolete.

    Please  note  that  if  the proposed changes to the fundamental investment
policy  are approved by shareholders, the Trustees have approved corresponding
changes  to  the  Fund's  name  policy,  which is set forth above, so that the
Fund's   name  policy  and  the  Fund's  policy  regarding  concentration  are
complementary.  The Fund's new name policy, which will take effect only if the
Fund's  shareholders  approve the proposed fundamental investment policy, will
be:

    The  Fund invests, under normal market conditions, at least 80% of its net
assets  in  securities  of  issuers principally engaged in offering, using, or
developing  products, processes, or services that will provide or will benefit
significantly from technological advances and improvements.

    The  Fund's investment objective and other fundamental investment policies
will not be affected by the proposed changes.

REQUIRED VOTE
    Approval  of  this  matter will require the vote of (i) 67% or more of the
outstanding  voting  securities  of  the  Fund  present at the Meeting, if the
holders  of more than 50% of the outstanding voting securities of the Fund are
present  or  represented  by  proxy  or  (ii) more than 50% of the outstanding
voting securities of the Fund, whichever is less.

    THE  TRUSTEES  OF THE TRUST UNANIMOUSLY RECOMMEND THAT THE SHAREHOLDERS OF
THE FUND VOTE TO APPROVE THIS PROPOSAL.

FUND INFORMATION

    This  section  provides  certain  information  about  the  Fund, including
information   about   its   investment   adviser,  principal  underwriter  and
administrator,  and  the  identity  of  persons  holding  more  than 5% of the
outstanding shares of any class of the Fund.


INVESTMENT ADVISER, PRINCIPAL UNDERWRITER AND ADMINISTRATOR
    The  Fund's  investment  adviser  and  administrator  is  MFS,  a Delaware
corporation  with offices at 500 Boylston Street, Boston, Massachusetts 02116.
The  Fund's  principal  underwriter  is MFS Fund Distributors, Inc. ("MFD"), a
Delaware   corporation   with   offices   at   500  Boylston  Street,  Boston,
Massachusetts  02116. MFS is a majority owned subsidiary of Sun Life of Canada
(U.S.)  Financial  Services  Holdings, Inc., which in turn is a majority-owned
subsidiary  of  Sun Life Financial (U.S.) Holdings, Inc., 500 Boylston Street,
Boston, Massachusetts 02116, which in turn is a wholly-owned subsidiary of Sun
Life  Assurance Company of Canada-U.S. Operations Holdings, Inc., One Sun Life
Executive   Park,   Wellesley  Hills,  Massachusetts  02481  ("Sun  Life  U.S.
Operations").  Sun  Life  U.S.  Operations is a wholly-owned subsidiary of Sun
Life  Financial Corp., 150 King Street West, Toronto, Canada MSH 1J9, which in
turn is a wholly-owned subsidiary of Sun Life Financial Inc.


INTERESTS OF CERTAIN PERSONS
    Schedule  A  attached  hereto  sets forth, as of June 5, 2006, to the best
knowledge of the Fund, the shareholders who beneficially owned more than 5% of
the outstanding shares of each class of the Fund.


FURTHER INFORMATION ABOUT VOTING AND THE MEETING

MANNER OF VOTING PROXIES
    All  proxies received by management will be voted on all matters presented
at  the  Meeting,  and  if  not limited to the contrary, will be voted FOR the
proposal to change the Fund's subclassification and FOR the proposal to change
the Fund's concentration policy.

    All  proxies received, including proxies that reflect (i) broker non-votes
(i.e.,  shares  held  by brokers or nominees as to which (a) instructions have
not  been received from the beneficial owners or the persons entitled to vote,
and  (b)  the  broker or nominee does not have discretionary voting power on a
particular  matter), (ii) abstentions or (iii) the withholding of authority to
vote,  will  be  counted as shares that are present on a particular matter for
purposes  of  determining the presence of a quorum for that matter. A majority
of  the  Fund's outstanding shares entitled to be cast at the Meeting that are
present  in  person or represented by proxy constitutes a quorum. With respect
to  each  proposal, broker non-votes, abstentions and withholding authority to
vote all will have the effect of a vote AGAINST the applicable proposal.

    The  Fund  will  reimburse  the  record  holders  of  its shares for their
expenses   incurred   in  sending  proxy  material  to  and  obtaining  voting
instructions from beneficial owners.

    The  Fund  knows of no other matters to be brought before the Meeting. If,
however,  because  of  any  unexpected  occurrence,  any matters properly come
before the Meeting, it is the Fund's intention that proxies not limited to the
contrary will be voted in accordance with the judgment of the persons named in
the enclosed form of proxy.

SOLICITATION OF PROXIES
    The  procedures  for voting proxies solicited by telephone or submitted by
the  Internet  or  by automated telephone service are designed to authenticate
shareholders'  identities,  to  allow  them  to  authorize the voting of their
shares  in  accordance  with  their  instructions  and  to  confirm that their
instructions  have been properly recorded. If these procedures were subject to
a  successful  legal challenge, such votes would not be counted at the meeting
of shareholders. The Fund is unaware of any such challenge at this time.

    If  shareholders' proxies are solicited by telephone, shareholders will be
called  at  the  phone  number  that  the  Fund  (or a shareholder's financial
intermediary)  has  in  its  records for their accounts, and will be asked for
their   Social   Security   number   or  other  identifying  information.  The
shareholders  will  then  be given an opportunity to authorize proxies to vote
their  shares  at  the  meeting  of  shareholders  in  accordance  with  their
instructions. To ensure that the shareholders' instructions have been recorded
correctly,  they will also receive a confirmation of their instructions in the
mail.  A  special  toll-free  number will be available in case the information
contained in the confirmation is incorrect.

INSTRUCTIONS FOR VOTING PROXIES
    The  giving  of  a  proxy will not affect a shareholder's right to vote in
person  should  the shareholder decide to attend the Meeting. To vote by mail,
please  mark,  sign,  date  and  return  the enclosed proxy card following the
instructions  printed  on  the  card.  To  use the Internet, please access the
Internet  address listed on your proxy card and follow the instructions on the
website.  To  record your voting instructions via automated telephone service,
please   call  the  toll-free  number  listed  on  the  enclosed  proxy  card.
Shareholders voting via the Internet should understand that there may be costs
associated  with electronic access, such as usage charges from Internet access
providers and telephone companies, that must be borne by the shareholders.

SUBMISSION OF PROPOSALS
    The  Fund  is  part  of a Massachusetts business trust, and as such is not
required  to  hold  annual meetings of shareholders. However, the Trustees may
from  time  to  time  schedule  special  meetings.  Shareholder  proposals for
inclusion  in  a  Fund's  proxy  statement  for any subsequent meeting must be
received  by the applicable Fund a reasonable period of time prior to any such
meeting.

ADDITIONAL INFORMATION
    Only  one  copy of this Proxy Statement may be mailed to a household, even
if more than one person in a household is a Fund shareholder of record, unless
the  Fund  has  received  contrary  instructions  from  one  or  more  of  the
shareholders.  If  you  need additional copies of this Proxy Statement and you
are  the  holder  of record of your shares, please contact MFS Service Center,
Inc.  at  1-800-637-2304. If your shares are held in broker street name please
contact  your financial intermediary to obtain additional copies of this proxy
statement. If in the future you do not want the mailing of proxy statements to
be  combined  with  those  for  other members of your household, or if you are
receiving  multiple copies of this Proxy Statement and want the mailings to be
combined  with  those for other members of your household, contact MFS Service
Center,  Inc.  in writing at 500 Boylston Street, Boston, Massachusetts 02116,
or by telephone at 800-637-2304, or contact your financial intermediary.

              IT IS IMPORTANT THAT PROXIES BE RETURNED PROMPTLY

June 12, 2006


                                                                    SCHEDULE A

                         INTERESTS OF CERTAIN PERSONS

    As  of  June  5,  2006,  to  the best knowledge of the Fund, the following
shareholders  beneficially owned more than 5% of the outstanding shares of any
class of the Fund.





                                                                                      NUMBER OF
                                                                                 OUTSTANDING SHARES
      TITLE OF                         NAME AND ADDRESS OF                          BENEFICIALLY                PERCENT OF
        CLASS                         BENEFICIAL SHAREHOLDER                            OWNED                      CLASS
- --------------------------------------------------------------------------------------------------------------------------

                                                                                                          
          C                 Merrill Lynch Pierce Fenner & Smith, Inc.                86,262.369                    6.78%
                              For the Sole Benefit of its Customers
                                       4800 Deer Lake Dr. E
                                      Jacksonville, FL 32246

          I                       TRS MFS Def Contribution Plan                     304,937.593                   91.47%
                            c/o                             Mark Leary
                                 MFS Investment Management, Inc.
                                500 Boylston Street, 6\t/\h/ Floor
                                         Boston, MA 02116

          I                             TRS MFS 401k Plan                            26,661.833                    7.99%
                            c/o                             Mark Leary
                                 MFS Investment Management, Inc.
                                500 Boylston Street, 6\t/\h/ Floor
                                         Boston, MA 02116

          R                      Arizona Machinery Employees PSP                     90,643.086                   30.10%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

          R                   403b Thrift Plan of Catholic Charities                 46,998.555                   15.60%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

          R                     Chou Chemical Profit Sharing Plan                    23,958.399                    7.95%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

         R1                     Stammer, McKnight, Barnum & Bailey                    7,116.051                   32.41%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

         R1                    Massachusetts Financial Services Co.                   6,242.197                   28.44%
                               Attn: Thomas Hastings, 9\t/\h/ Floor
                                         500 Boylston St.
                                         Boston, MA 02116

         R1                   Obarski Machine & Tool Company 401(k)                   2,797.535                   12.74%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

         R1                          Westmed Ambulance 401(k)                         1,643.874                    7.48%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

         R1                             Palms 401(k) Plan                             1,383.970                    6.30%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

         R1                         C.A.R.E., Inc. 401(k) PSP                         1,400.170                    6.37%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

         R2                      Graphic Image, Inc. 401(k) Plan                     27,071.604                   68.46%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

         R2                          Exigen Group 401(k) Plan                        16,380.956                   21.07%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

         R2                    Massachusetts Financial Services Co.                   6,242.197                   15.79%
                               Attn: Thomas Hastings, 9\t/\h/ Floor
                                       500 Boylston Street
                                         Boston, MA 02116

         R2                       Pacific Peninsula Group 401(k)                      4,147.575                   10.48%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

         R2                    Page Brake 401(k) Retirement Savings                   6,217.714                    7.99%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

         R2                      Kilmer Wagner & Wise 401(k) Plan                     5,956.393                    7.66%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

         R2                   Grangettos Farm & Garden Supply 401(k)                  4,689.195                    6.03%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

         R3                     Motor Service, Inc. Profit Sharing                   11,231.665                   14.45%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

         R3                   First Piedmont Federal Savings & Loan                   9,238.089                   11.88%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

         R3                   Wesely-Thomas Enterprises, Inc. 401(k)                  9,134.709                   11.75%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

         R4                            Acrison, Inc. 401(k)                          25,354.092                   69.56%
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

         R4                    Massachusetts Financial Services Co.                   6,053.269                   16.61%
                               Attn: Thomas Hastings, 9\t/\h/ Floor
                                       500 Boylston Street
                                         Boston, MA 02116

         R4                          BCA Holding Company Ltd.                         5,038.555                   13.82%
                                    401(k) Retirement Savings
                                      Attn: C. Giorgi VP-RSI
                                    MFS Investment Management
                                       500 Boylston Street
                                         Boston, MA 02116

         R5                    Massachusetts Financial Services Co.                   6,053.269                  100.00%
                               Attn: Thomas Hastings, 9\t/\h/ Floor
                                       500 Boylston Street
                                         Boston, MA 02116




                                                                  SCT-PRX-6/06
                                                                           23M

                                M F S(SM)
                           INVESTMENT MANAGEMENT(R)

- -------------------------------------------------------------------------------
                       THREE EASY WAYS TO VOTE YOUR PROXY
           Read the Proxy Statement and have the Proxy card at hand.
      TELEPHONE: Call 1-888-221-0697 and follow the simple instructions.
      INTERNET: Go to www.proxyweb.com and follow the on-line directions.
             MAIL: Vote, sign, date and return your proxy by mail.
         IF YOU VOTE BY TELEPHONE OR INTERNET, DO NOT MAIL YOUR PROXY.
- -------------------------------------------------------------------------------

999 999 999 999 99 <<

   THIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF TRUSTEES OF MFS SERIES
                   TRUST I, ON BEHALF OF MFS TECHNOLOGY FUND

            PROXY FOR THE MEETING OF SHAREHOLDERS TO BE HELD ON AUGUST 15, 2006

The undersigned hereby appoints Mses. Susan S. Newton, Tracy A. Atkinson, Susan
A. Pereira and Messrs. Mark N. Polebaum and Timothy M. Fagan and each of them
separately, proxies, with power of substitution, and hereby authorizes each of
them to represent, and to vote, as designated on the reverse side, at the
Meeting of Shareholders of the above-referenced Fund, on Tuesday, August 15,
2006 at 9:30 a.m., Boston time, and at any adjournments thereof, all of the
shares of the Fund that the undersigned would be entitled to vote if personally
present. THIS PROXY WHEN PROPERLY EXECUTED WILL BE VOTED IN THE MANNER DIRECTED
HEREIN BY THE UNDERSIGNED SHAREHOLDER. IF NO DIRECTION IS MADE, THIS PROXY WILL
BE VOTED FOR ALL PROPOSALS. IN THEIR DISCRETION, THE PROXIES ARE AUTHORIZED TO
VOTE UPON SUCH OTHER MATTERS AS MAY PROPERLY COME BEFORE THE MEETING. THE
TRUSTEES RECOMMEND A VOTE FOR THE PROPOSALS ON THE REVERSE SIDE.

                                               Date ________________________

                                               THIS PROXY CARD IS VALID ONLY
                                                  WHEN SIGNED AND DATED

                                           ------------------------------------


                                           ------------------------------------

                                           Signature (PLEASE SIGN WITHIN BOX)

                                           NOTE: Please sign exactly as your
                                           name appears on this card. All joint
                                           owners should sign. When signing as
                                           executor, administrator, attorney,
                                           trustee or guardian or as custodian
                                           for a minor, please give full title
                                           as such. If a corporation, please
                                           sign in full corporate name and
                                           indicate the signer's office. If a
                                           partnership, sign in the partnership
                                           name.

                                                                  MFS Tech - fg


Please fill in box(es) as shown using black or blue ink or number 2 pencil.  [X]
PLEASE DO NOT USE FINE POINT PENS.

YOUR TRUSTEES RECOMMEND THAT YOU VOTE FOR ALL ITEMS.


YOUR TRUSTEES RECOMMEND THAT YOU VOTE FOR ALL ITEMS.

                                                        FOR   AGAINST   ABSTAIN

ITEM 1. To approve a change to the Fund's               [ ]     [ ]       [ ]
        sub-classification under the Investment
        Company Act of 1940 from a diversified
        company to a non-diversified company.

ITEM 2. To approve an amendment to the Fund's           [ ]     [ ]       [ ]
        fundamental investment policy concerning
        concentration.

                   PLEASE SIGN AND DATE ON THE REVERSE SIDE.
                                                                  MFS Tech - fg