<PAGE>
MFS CASH RESERVE FUND
SUPPLEMENT TO THE CURRENT PROSPECTUS
This supplement describes certain changes to the imposition and waivers
of sales charges with respect to the Fund's Class B shares purchased by certain
retirement plans.
Class B shares are offered at net asset value without an initial sales
charge but subject to a contingent deferred sales charge ("CDSC") upon
redemption as described in the Fund's Prospectus. In the case of such purchases,
MFD generally pays an amount to dealers equal to 4.00% of the amount purchased
through such dealers, which is comprised of a commission of 3.75% plus the
advancement of the first year service fee equal to 0.25% of the purchase price
payable under the Class B Distribution Plan.
Class B shares purchased by a retirement plan whose sponsoring
organization subscribes to the MFS FUNDamental 401(k) Program or any similar
recordkeeping system made available by MFS Service Center, Inc. (the
"Shareholder Servicing Agent") (the "MFS Participant Recordkeeping System") and
which has established its account with the Shareholder Servicing Agent ON OR
AFTER July 1, 1996, will be subject to the CDSC described in the Fund's
Prospectus only under limited circumstances, as explained below. With respect to
such purchases, MFD pays an amount to dealers equal to 3.00% of the amount
purchased through such dealers (rather than the 4.00% payment described above),
which is comprised of a commission of 2.75% plus the advancement of the first
year service fee equal to 0.25% of the purchase price payable under the Class B
Distribution Plan.
In certain circumstances, the CDSC imposed upon the redemption of Class
B shares is waived. These circumstances are described in Appendix A to the
Prospectus. In addition to these circumstances, the CDSC imposed upon the
redemption of Class B shares is waived with respect to shares held by a
retirement plan whose sponsoring organization subscribes to the MFS Participant
Recordkeeping System and which has established an account with the Shareholder
Servicing Agent ON OR AFTER July 1, 1996; PROVIDED HOWEVER, that the CDSC will
not be waived (I.E., it will be imposed) in the event that there is a change in
law or regulations which results in a material adverse change to the tax
advantaged nature of the plan, or in the event that the plan and/or sponsoring
organization: (i) becomes insolvent or bankrupt; (ii) is terminated or partially
terminated under ERISA or is liquidated or dissolved; or (iii) is acquired by,
merged into, or consolidated with, any other entity.
The date of this Supplement is July 1, 1996.
