Prospectus

(RIVERSOURCE INVESTMENTS LOGO)

RIVERSOURCE(R)
DIVERSIFIED BOND FUND

PROSPECTUS OCT. 30, 2007
RIVERSOURCE DIVERSIFIED BOND FUND SEEKS TO PROVIDE SHAREHOLDERS WITH A HIGH
LEVEL OF CURRENT INCOME WHILE CONSERVING THE VALUE OF THE INVESTMENT FOR THE
LONGEST PERIOD OF TIME.

Classes A, B, C, I, R2, R3, R4, R5 and W

As with all mutual funds, the Securities and
Exchange Commission has not approved or
disapproved these securities or passed upon the
adequacy of this prospectus.
Any representation to the contrary is a criminal
offense.

You may qualify for sales charge discounts on purchases of Class A
shares. Please notify your financial institution if you have other
accounts holding shares of RiverSource funds to determine whether
you qualify for a sales charge discount. See "Buying and Selling
Shares" for more information.

NOT FDIC INSURED - MAY LOSE VALUE - NO BANK GUARANTEE

TABLE OF CONTENTS

<Table>

THE FUND.................................................... 3P
Objective................................................... 3p
Principal Investment Strategies............................. 3p
Principal Risks............................................. 4p
Past Performance............................................ 7p
Fees and Expenses........................................... 11p
Other Investment Strategies and Risks....................... 13p
Fund Management and Compensation............................ 15p
FINANCIAL HIGHLIGHTS........................................ 17P
BUYING AND SELLING SHARES................................... S.1
Description of Share Classes................................ S.1
Investment Options -- Classes of Shares ................. S.1
Sales Charges............................................ S.5
Opening an Account....................................... S.10
Exchanging or Selling Shares................................ S.13
Exchanges................................................ S.15
Selling Shares........................................... S.17
VALUING FUND SHARES......................................... S.18
DISTRIBUTIONS AND TAXES..................................... S.19
Dividends and Capital Gain Distributions.................... S.19
Reinvestments............................................... S.19
Taxes....................................................... S.19
GENERAL INFORMATION......................................... S.21
</Table>

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2P RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS

THE FUND

OBJECTIVE

RiverSource Diversified Bond Fund (the Fund) seeks to provide shareholders with
a high level of current income while conserving the value of the investment for
the longest period of time. Because any investment involves risk, there is no
assurance this objective can be achieved. Only shareholders can change the
Fund's objective.

PRINCIPAL INVESTMENT STRATEGIES

Under normal market conditions, the Fund invests at least 80% of its net assets
in bonds and other debt securities. At least 50% of the Fund's net assets will
be invested in securities like those included in the Lehman Brothers Aggregate
Bond Index (the Index), which are investment grade and denominated in U.S.
dollars. The Index includes securities issued by the U.S. government, corporate
bonds, and mortgage- and asset-backed securities. Although the Fund emphasizes
high- and medium-quality debt securities, it will assume some credit risk in an
effort to achieve higher yield and/or capital appreciation by buying
lower-quality (junk) bonds. Up to 25% of the Fund's net assets may be invested
in foreign investments, which may include investments in emerging markets. The
Fund will provide shareholders with at least 60 days' notice of any change in
the 80% policy.

The selection of debt obligations is the primary decision in building the
investment portfolio. In pursuit of the Fund's objective, the investment manager
(RiverSource Investments, LLC) chooses investments by:

- - Evaluating the portfolio's total exposure to sectors, industries and
securities relative to the Index.

- - Analyzing factors such as credit quality, interest rate outlook and price in
seeking to select the most attractive securities within each sector.

- - Investing in lower-quality (junk) bonds and foreign investments as attractive
opportunities arise.

- - Targeting an average portfolio duration within one year of the duration of the
Index which, as of Aug. 31, 2007, was 4.64 years. Duration measures the
sensitivity of bond prices to changes in interest rates. The longer the
duration of a bond, the longer it will take to repay the principal and
interest obligations and the more sensitive it will be to changes in interest
rates. For example, a five-year duration means a bond is expected to decrease
in value by 5% if interest rates rise 1% and increase in value by 5% if
interest rates fall 1%.

In evaluating whether to sell a security, the investment manager considers,
among other factors:

- - Identification of more attractive investments based on relative value.

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RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS 3P

- - The portfolio's total exposure to sectors, industries and securities relative
to the Index.

- - Whether a security's rating has changed or is vulnerable to a change.

- - Whether a sector or industry is experiencing change.

- - Changes in the interest rate or economic outlook.

The investment manager may use derivatives such as futures, options, forward
contracts and swaps, including credit default swaps, in an effort to produce
incremental earnings, to hedge existing positions, to increase market exposure
and investment flexibility, or to obtain or reduce credit exposure.

PRINCIPAL RISKS

Please remember that with any mutual fund investment you may lose money.
Principal risks associated with an investment in the Fund include:

ACTIVE MANAGEMENT RISK. The Fund is actively managed and its performance
therefore will reflect in part the ability of the portfolio managers to select
securities and to make investment decisions that are suited to achieving the
Fund's investment objective. Due to its active management, the Fund could
underperform other mutual funds with similar investment objectives.

CREDIT RISK. Credit risk is the risk that the issuer of a security, or the
counterparty to a contract, will default or otherwise become unable or unwilling
to honor a financial obligation, such as payments due on a bond or a note. If
the Fund purchases unrated securities, or if the rating of a security is reduced
after purchase, the Fund will depend on the investment manager's analysis of
credit risk more heavily than usual. Non-investment grade securities, commonly
called "high-yield" or "junk" bonds, may react more to perceived changes in the
ability of the issuing entity to pay interest and principal when due than to
changes in interest rates. Non-investment grade securities have greater price
fluctuations and are more likely to experience a default than investment grade
bonds.

DERIVATIVES RISK. Derivatives are financial instruments that have a value which
depends upon, or is derived from, the value of something else, such as one or
more underlying securities, pools of securities, options, futures, indexes or
currencies. Gains or losses involving derivative instruments may be substantial,
because a relatively small price movement in the underlying security(ies),
instrument, currency or index may result in a substantial gain or loss for the
Fund. Derivative instruments in which the Fund invests will typically increase
the Fund's exposure to Principal Risks to which it is otherwise exposed, and may
expose the Fund to additional risks, including counterparty credit risk,
leverage risk, hedging risk, correlation risk, and liquidity risk.

Hedging Risk. Hedging risk is the risk that derivative instruments used to hedge
against an opposite position, may offset losses, but they may also offset gains.

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4P RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS

Correlation Risk. Correlation risk is related to hedging risk and is the risk
that there may be an incomplete correlation between the hedge and the opposite
position, which may result in increased or unanticipated losses.

Liquidity Risk. Liquidity risk is the risk that the derivative instrument may be
difficult or impossible to sell or terminate, which may cause the Fund to be in
a position to do something the investment manager would not otherwise choose,
including accepting a lower price for the derivative instrument, selling other
investments or foregoing another, more appealing investment opportunity.

Leverage Risk. Leverage risk is the risk that losses from the derivative
instrument may be greater than the amount invested in the derivative instrument.
Certain derivatives have the potential for unlimited losses, regardless of the
size of the initial investment. See the SAI for more information on derivative
instruments and related risks.

FOREIGN/EMERGING MARKETS RISK. The following are all components of
foreign/emerging markets risk:

Country risk includes the political, economic, and other conditions of the
country. These conditions include lack of publicly available information, less
government oversight (including lack of accounting, auditing, and financial
reporting standards), the possibility of government-imposed restrictions, and
even the nationalization of assets. The liquidity of foreign investments may be
more limited than for most U.S. investments, which means that, at times it may
be difficult to sell foreign securities at desirable prices.

Currency risk results from the constantly changing exchange rate between local
currency and the U.S. dollar. Whenever the Fund holds securities valued in a
foreign currency or holds the currency, changes in the exchange rate add to or
subtract from the value of the investment.

Custody risk refers to the process of clearing and settling trades. It also
covers holding securities with local agents and depositories. Low trading
volumes and volatile prices in less developed markets make trades harder to
complete and settle. Local agents are held only to the standard of care of the
local market. Governments or trade groups may compel local agents to hold
securities in designated depositories that are not subject to independent
evaluation. The less developed a country's securities market is, the greater the
likelihood of problems occurring.

Emerging markets risk includes the dramatic pace of change (economic, social and
political) in these countries as well as the other considerations listed above.
These markets are in early stages of development and are extremely volatile.
They can be marked by extreme inflation, devaluation of currencies, dependence
on trade partners and hostile relations with neighboring countries.

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RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS 5P

INTEREST RATE RISK. Interest rate risk is the risk of losses attributable to
changes in interest rates. Interest rate risk is generally associated with bond
prices: when interest rates rise, bond prices fall. In general, the longer the
maturity or duration of a bond, the greater its sensitivity to changes in
interest rates.

LIQUIDITY RISK. The risk associated from a lack of marketability of securities
which may make it difficult or impossible to sell at desirable prices in order
to minimize loss. The Fund may have to lower the selling price, sell other
investments, or forego another, more appealing investment opportunity.

MARKET RISK. The market value of securities may fall or fail to rise. Market
risk may affect a single issuer, sector of the economy, industry, or the market
as a whole. The market value of securities may fluctuate, sometimes rapidly and
unpredictably.

PREPAYMENT AND EXTENSION RISK. Prepayment and extension risk is the risk that a
bond or other security might be called or otherwise converted, prepaid, or
redeemed before maturity. This risk is primarily associated with asset-backed
securities, including mortgage-backed securities. If a security is converted,
prepaid, or redeemed before maturity, particularly during a time of declining
interest rates, the investment manager may not be able to reinvest in securities
providing as high a level of income, resulting in a reduced yield to the Fund.
Conversely, as interest rates rise, the likelihood of prepayment decreases. The
investment manager may be unable to capitalize on securities with higher
interest rates because the Fund's investments are locked in at a lower rate for
a longer period of time.

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6P RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS

PAST PERFORMANCE

The following bar chart and table provide some illustration of the risks of
investing in the Fund by showing, respectively:

- - how the Fund's performance has varied for each full calendar year shown on the
bar chart; and

- - how the Fund's average annual total returns compare to recognized indexes
shown on the table.

Both the bar chart and the table assume that all distributions have been
reinvested. The performance of different classes varies because of differences
in sales charges and other fees and expenses. How the Fund has performed in the
past (before and after taxes) does not indicate how the Fund will perform in the
future. Performance reflects any fee waivers/expense caps in effect for the
periods reported. In the absence of such fee waivers/expense caps, performance
would have been lower. See "Fees and Expenses" for any current fee
waivers/expense caps.

Bar Chart. Class A share information is shown in the bar chart; the sales charge
for Class A shares is not reflected in the bar chart.

Table. The table shows total returns from hypothetical investments in Class A,
Class B, Class C, Class I, and Class R4 shares of the Fund. These returns are
compared to the indexes shown for the same periods. For purposes of the
performance calculation in the table we assumed:

- - the maximum sales charge for Class A shares;

- - sales at the end of the period and deduction of the applicable contingent
deferred sales charge (CDSC) for Class B and Class C shares;

- - no sales charge for Class I, and Class R4 shares; and

- - with the exception of Class A shares, no adjustments for taxes paid by an
investor on the reinvested income and capital gains.

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RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS 7P

AFTER-TAX RETURNS

After-tax returns are shown only for Class A shares. After-tax returns for the
other classes will vary. After-tax returns are calculated using the highest
historical individual federal marginal income tax rate and do not reflect the
impact of state and local taxes. Actual after-tax returns will depend on your
tax situation and most likely will differ from the returns shown in the table.
If you hold your shares in a tax-deferred account, such as a 401(k) plan or an
IRA, the after-tax returns do not apply to you since you will not incur taxes
until you begin to withdraw from your account.

The return after taxes on distributions for a period may be the same as the
return before taxes for the same period if there were no distributions or if the
distributions were small. The return after taxes on distributions and sale of
Fund shares for a period may be greater than the return before taxes for the
same period if there was a tax loss realized on sale of Fund shares. The benefit
of the tax loss (since it can be used to offset other gains) may result in a
higher return.

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CLASS A SHARE PERFORMANCE
(BASED ON CALENDAR YEARS)
(BAR CHART)

<Table>

+9.94% +5.86% -0.22% +7.03% +7.33% +5.63% +4.61% +4.41% +2.09% +5.37%
1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
</Table>

During the periods shown in the bar chart, the highest return for a calendar
quarter was +3.80% (quarter ended June 30, 1997) and the lowest return for a
calendar quarter was -2.53% (quarter ended June 30, 2004).

The 4.75% sales charge applicable to Class A shares of the Fund is not reflected
in the bar chart; if reflected, returns would be lower than those shown. The
performance of other classes may vary from that shown because of differences in
expenses.

The Fund's Class A year-to-date return at Sept. 30, 2007, was +3.34%.

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8P RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS

AVERAGE ANNUAL TOTAL RETURNS (FOR PERIODS ENDED DEC. 31, 2006)

<Table>
<Caption>
SINCE SINCE
INCEPTION INCEPTION
1 YEAR 5 YEARS 10 YEARS (CLASS C) (CLASS I)

RiverSource Diversified Bond
Fund:
Class A
Return before taxes +0.37% +3.40% +4.66% N/A N/A
Return after taxes on
distributions -1.16% +1.88% +2.45% N/A N/A
Return after taxes on
distributions and sale of
fund shares +0.21% +1.98% +2.59% N/A N/A
Class B
Return before taxes -0.64% +3.28% +4.38% N/A N/A
Class C
Return before taxes +3.35% +3.62% N/A +4.68%(a) N/A
Class I
Return before taxes +5.73% N/A N/A N/A +4.05%(b)
Class R4*
Return before taxes +5.55% +4.58% +5.32% N/A N/A
Lehman Brothers Aggregate Bond
Index (reflects no deduction
for fees, expenses or taxes) +4.33% +5.06% +6.24% +6.33%(c) +3.23%(d)
Lipper Intermediate Investment
Grade Index +4.47% +4.93% +5.87% +6.15%(c) +3.25%(d)
</Table>

* Effective Dec. 11, 2006, Class Y was renamed Class R4.
(a) Inception date is June 26, 2000.
(b) Inception date is March 4, 2004.
(c) Measurement period started July 1, 2000.
(d) Measurement period started March 1, 2004.

The Lehman Brothers Aggregate Bond Index, an unmanaged index, is made up of a
representative list of government, corporate, asset-backed and mortgage-backed
securities. The index is frequently used as a general measure of bond market
performance. The index reflects reinvestment of all distributions and changes in
market prices.

The Lipper Intermediate Investment Grade Index includes the 30 largest
investment grade funds tracked by Lipper Inc. The index's returns include net
reinvested dividends.

Classes R2, R3, R5 and W have not been in existence for a full calendar year and
therefore performance information for these classes is not shown.

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RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS 9P

Past performance for Class R2 for the period prior to the beginning of
operations for that class may be calculated based on the performance of Class B.
Past performance for Class R3 and Class W for the period prior to the beginning
of operations for that class may be calculated based on the performance of Class
A. Past performance for Class R5 for the period prior to the beginning of
operations for that class may be calculated based on the performance of Class
R4. In each case, the blended class performance will be adjusted to reflect
differences in sales charges, but not differences in annual Fund operating
expenses (for example, 12b-1 fees). The use of blended performance generally
results in higher performance for classes with higher operating expenses than
those of the class with which they are blended, and lower performance for
classes with lower operating expenses than those of the class with which they
are blended.

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10P RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS

FEES AND EXPENSES

Fund investors pay various expenses. The table below describes the fees and
expenses that you may pay if you buy and hold shares of the Fund. Expenses are
based on the Fund's most recent fiscal year, adjusted to reflect current fees.

SHAREHOLDER FEES (FEES PAID DIRECTLY FROM YOUR INVESTMENT)

CLASS I
CLASS R2
CLASS R3
CLASS R4(b)
CLASS R5
CLASS A CLASS B CLASS C CLASS W

Maximum sales charge (load) imposed on
purchases (as a percentage of offering
price) 4.75%(a) None None None
Maximum deferred sales charge (load)
imposed on sales (as a percentage of
offering price at time of purchase) None 5% 1% None
</Table>

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT ARE DEDUCTED FROM FUND ASSETS)

AS A PERCENTAGE OF AVERAGE DAILY NET ASSETS:
CLASS A CLASS B CLASS C CLASS W

Management fees 0.46% 0.46% 0.46% 0.46%
Distribution (12b-1) fees 0.25% 1.00% 1.00% 0.25%
Other expenses(c) 0.26% 0.27% 0.27% 0.30%
Total annual fund operating expenses 0.97% 1.73% 1.73% 1.01%
Fee waiver/expense reimbursement 0.08% 0.08% 0.08% 0.03%
Total annual (net) fund operating expenses(d) 0.89% 1.65% 1.65% 0.98%
</Table>

CLASS
CLASS I CLASS R2 CLASS R3 R4(b) CLASS R5

Management fees 0.46% 0.46% 0.46% 0.46% 0.46%
Distribution (12b-1) fees 0.00% 0.50% 0.25% 0.00% 0.00%
Other expenses(c) 0.10% 0.40% 0.40% 0.40% 0.15%
Total annual fund operating
expenses 0.56% 1.36% 1.11% 0.86% 0.61%
Fee waiver/expense reimbursement 0.03% 0.03% 0.03% 0.09% 0.03%
Total annual (net) fund operating
expenses(d) 0.53% 1.33% 1.08% 0.77% 0.58%
</Table>

(a) This charge may be reduced depending on the value of your total investments
in RiverSource Funds. See "Sales Charges."
(b) Effective Dec. 11, 2006, the following changes were implemented: renaming
Class Y as Class R4, terminating the shareholder servicing agreement,
revising the fee structure under the transfer agent agreement from
account-based to asset-based, and adopting a plan administration services
agreement.
(c) Other expenses include an administrative services fee, a transfer agency
fee, a custody fee, other nonadvisory expenses and, for Class R2, Class R3
and Class R4, a plan administration services fee. Other expenses may also
include fees and expenses of affiliated and unaffiliated funds (acquired
funds) which the Fund indirectly bears when it invests in the acquired
funds. Because acquired funds will have varied expense and fee levels and
the Fund may own different proportions of acquired funds at different
times, the amount of fees and expenses incurred by the Fund with respect to
such investments will vary.

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RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS 11P

(d) The investment manager and its affiliates have contractually agreed to
waive certain fees and to absorb certain expenses until Aug. 31, 2008,
unless sooner terminated at the discretion of the Fund's Board. Any amounts
waived will not be reimbursed by the Fund. Under this agreement, net fund
expenses (excluding fees and expenses of acquired funds), will not exceed
0.89% for Class A, 1.65% for Class B, 1.65% for Class C, 0.53% for Class I,
1.33% for Class R2, 1.08% for Class R3, 0.77% for Class R4, 0.58% for Class
R5 and 0.98% for Class W.
[(e) In addition to the Fund's total annual operating expenses that the Fund
bears directly, the Fund's shareholders indirectly bear the expenses of the
acquired funds (affiliated and unaffiliated funds) in which the Fund
invests. The Fund's "Acquired fund fees and expenses," based on its
investment in the acquired funds, is as shown.

EXAMPLES

These examples are intended to help you compare the cost of investing in the
Fund with the cost of investing in other mutual funds.

These examples assume that you invest $10,000 in the Fund for the time periods
indicated and then redeem all of your shares at the end of those periods. These
examples also assume that your investment has a 5% return each year and that the
Fund's operating expenses remain the same. Although your actual costs may be
higher or lower, based on these assumptions your costs would be:

<Table>
<Caption>
1 YEAR 3 YEARS 5 YEARS 10 YEARS

Class A(a) $561 $761 $ 978 $1,602
Class B $667(b) $937(b) $1,131(b) $1,834(c)
Class C $267(b) $537 $ 931 $2,036
Class I $ 54 $176 $ 309 $ 698
Class R2 $135 $427 $ 741 $1,634
Class R3 $110 $349 $ 608 $1,350
Class R4 $ 78 $265 $ 467 $1,053
Class R5 $ 59 $192 $ 336 $ 759
Class W $100 $318 $ 554 $1,235
</Table>

(a) Includes a 4.75% sales charge.
(b) Includes the applicable CDSC.
(c) Based on conversion of Class B shares to Class A shares in the ninth year
of ownership.

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12P RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS

You would pay the following expenses if you did not redeem your shares:

<Table>
<Caption>
1 YEAR 3 YEARS 5 YEARS 10 YEARS

Class A(a) $561 $761 $978 $1,602
Class B $167 $537 $931 $1,834(b)
Class C $167 $537 $931 $2,036
Class I $ 54 $176 $309 $ 698
Class R2 $135 $427 $741 $1,634
Class R3 $110 $349 $608 $1,350
Class R4 $ 78 $265 $467 $1,053
Class R5 $ 59 $192 $336 $ 759
Class W $100 $318 $554 $1,235
</Table>

(a) Includes a 4.75% sales charge.
(b) Based on conversion of Class B shares to Class A shares in the ninth year
of ownership.

OTHER INVESTMENT STRATEGIES AND RISKS

Other Investment Strategies. In addition to the principal investment strategies
previously described, the Fund may utilize investment strategies that are not
principal investment strategies, including investment in affiliated and
non-affiliated pooled investment vehicles (including mutual funds and exchange
traded funds(ETFs), also referred to as "acquired funds") ownership of which
results in the Fund bearing its proportionate share of the acquired funds' fees
and expenses. Although ETFs are designed to replicate the price and yield of a
specified market index, there is no guarantee that an ETF will track its
specified market index, which may result in a loss. For more information on
strategies and holdings, and the risks of such strategies, including derivative
instruments that the Fund may use, see the Fund's Statement of Additional
Information (SAI) and its annual and semiannual reports.

Unusual Market Conditions. During unusual market conditions, the Fund may
temporarily invest more of its assets in money market securities than during
normal market conditions. Although investing in these securities would serve
primarily to attempt to avoid losses, this type of investing also could prevent
the Fund from achieving its investment objective. During these times, the
portfolio managers may make frequent securities trades that could result in
increased fees, expenses and taxes, and decreased performance. Instead of
investing in money market securities directly, the Fund may invest in shares of
an affiliated money market fund. See "Cash Reserves" for more information.

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RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS 13P

Securities Transaction Commissions. Securities transactions involve the payment
by the Fund of brokerage commissions to broker-dealers, on occasion as
compensation for research or brokerage services (commonly referred to as "soft
dollars"), as the portfolio managers buy and sell securities for the Fund in
pursuit of its objective. A description of the policies governing the Fund's
securities transactions and the dollar value of brokerage commissions paid by
the Fund are set forth in the SAI. Funds that invest primarily in fixed income
securities do not typically generate brokerage commissions that are used to pay
for research or brokerage services. The brokerage commissions set forth in the
SAI do not include implied commissions or mark-ups (implied commissions) paid by
the Fund for principal transactions (transactions made directly with a dealer or
other counterparty), including most fixed income securities (and certain other
instruments, including derivatives). Brokerage commissions do not reflect other
elements of transaction costs, including the extent to which the Fund's purchase
and sale transactions may cause the market to move and change the market price
for an investment.

Although brokerage commissions and implied commissions are not reflected in the
expense table under "Fees and Expenses," they are reflected in the total return
of the Fund.

Portfolio Turnover. Trading of securities may produce capital gains, which are
taxable to shareholders when distributed. Active trading may also increase the
amount of brokerage commissions paid or mark-ups to broker-dealers that the Fund
pays when it buys and sells securities. Capital gains and increased brokerage
commissions or mark-ups paid to broker-dealers may adversely affect a fund's
performance. The Fund's historical portfolio turnover rate, which measures how
frequently the Fund buys and sells investments, is shown in the "Financial
Highlights."

Directed Brokerage. The Fund's Board of Directors (Board) has adopted a policy
prohibiting the investment manager, or any subadviser, from considering sales of
shares of the Fund as a factor in the selection of broker-dealers through which
to execute securities transactions.

Additional information regarding securities transactions can be found in the
SAI.

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14P RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS

FUND MANAGEMENT AND COMPENSATION

INVESTMENT MANAGER

RiverSource Investments, LLC (the investment manager or RiverSource
Investments), 200 Ameriprise Financial Center, Minneapolis, Minnesota 55474, is
the investment manager to the RiverSource funds, and is a wholly-owned
subsidiary of Ameriprise Financial, Inc. (Ameriprise Financial). Ameriprise
Financial is a financial planning and financial services company that has been
offering solutions for clients' asset accumulation, income management and
protection needs for more than 110 years. In addition to managing investments
for all of the RiverSource funds, RiverSource Investments manages investments
for itself and its affiliates. For institutional clients, RiverSource
Investments and its affiliates provide investment management and related
services, such as separate account asset management, and institutional trust and
custody, as well as other investment products. For all of its clients,
RiverSource Investments seeks to allocate investment opportunities in an
equitable manner over time. See the SAI for more information.

The Fund pays RiverSource Investments a fee for managing its assets. Under the
Investment Management Services Agreement (Agreement), the fee for the most
recent fiscal year was 0.46% of the Fund's average daily net assets. Under the
Agreement, the Fund also pays taxes, brokerage commissions, and nonadvisory
expenses. A discussion regarding the basis for the Board approving the Agreement
is available in the Fund's most recent annual or semiannual shareholder report.

Portfolio Manager(s). The portfolio managers responsible for the day-to-day
management of the Fund are:

Jamie Jackson, CFA, Portfolio Manager

- - Co-managed the Fund since 2003.

- - Leader of the liquid assets sector team.

- - Joined RiverSource Investments in 2003.

- - Co-head of U.S. Investment Grade Fixed Income, UBS Global Asset Management,
1997 to 2003.

- - Began investment career in 1988.

- - MBA, Marquette University.

Scott Kirby, Portfolio Manager

- - Co-managed the Fund since 2003.

- - Leader of the structured assets sector team.

- - Employed by RiverSource Investments from 1979 to 1985 and from 1987 to the
present.

- - Began investment career in 1979.

- - MBA, University of Minnesota.

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

RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS 15P

Tom Murphy, CFA, Portfolio Manager

- - Co-managed the Fund since 2003.

- - Leader of the investment grade corporate bond sector team.

- - Joined RiverSource Investments in 2002.

- - Managing Director and Portfolio Manager, BlackRock Financial Management, 2002;
various positions, Zurich Scudder, 1992 to 2002.

- - Began investment career in 1986.

- - MBA, University of Michigan.

Nicholas Pifer, CFA, Portfolio Manager

- - Co-managed the Fund since 2003.

- - Leader of the global sector team.

- - Joined RiverSource Investments in 2000.

- - Fixed Income Portfolio Manager, Investment Advisers, Inc., 1997 to 2000.

- - Began investment career in 1990.

- - MA, Johns Hopkins University School of Advanced International Studies.

Jennifer Ponce de Leon, Portfolio Manager

- - Co-managed the Fund since 2003.

- - Leader of the high yield sector team.

- - Joined RiverSource Investments in 1997.

- - Began investment career in 1989.

- - MBA, De Paul University.

The fixed income department of RiverSource Investments is divided into six
sector teams, each of which includes a portfolio manager or portfolio managers
and several analysts, and each of which specializes in a specific sector of the
fixed income market. The Fund's portfolio managers lead the teams that
specialize in the sectors in which the Fund primarily invests, and collectively
determine allocation of Fund assets among the sectors.

The SAI provides additional information about portfolio manager compensation,
management of other accounts and ownership of shares in the Fund.

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

16P RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS

FINANCIAL HIGHLIGHTS

THE FINANCIAL HIGHLIGHTS TABLES ARE INTENDED TO HELP YOU UNDERSTAND THE FUND'S
FINANCIAL PERFORMANCE. CERTAIN INFORMATION REFLECTS FINANCIAL RESULTS FOR A
SINGLE FUND SHARE. THE TOTAL RETURNS IN THE TABLES REPRESENT THE RATE THAT AN
INVESTOR WOULD HAVE EARNED OR LOST ON AN INVESTMENT IN THE FUND (ASSUMING
REINVESTMENT OF ALL DIVIDENDS AND DISTRIBUTIONS). THE INFORMATION FOR THE FISCAL
YEAR ENDED AUG. 31, 2007 HAS BEEN DERIVED FROM THE FINANCIAL STATEMENTS AUDITED
BY ERNST & YOUNG LLP, WHOSE REPORT, ALONG WITH THE FUND'S FINANCIAL STATEMENTS
AND FINANCIAL HIGHLIGHTS, IS INCLUDED IN THE ANNUAL REPORT WHICH, IF NOT
INCLUDED WITH THIS PROSPECTUS, IS AVAILABLE UPON REQUEST. THE INFORMATION FOR
THE PERIODS ENDED ON OR BEFORE AUG. 31, 2006 HAS BEEN AUDITED BY KPMG LLP.

CLASS A

<Table>
<Caption>
PER SHARE INCOME AND CAPITAL CHANGES(a)
FISCAL PERIOD ENDED AUG. 31, 2007 2006 2005 2004 2003

Net asset value, beginning of period $4.77 $4.89 $4.87 $4.78 $4.75
- -----------------------------------------------------------------------------------------------------------
INCOME FROM INVESTMENT OPERATIONS:
Net investment income (loss) .21(b) .19 .18 .18 .20
Net gains (losses) (both realized and
unrealized) .05 (.11) .03 .08 .03
- -----------------------------------------------------------------------------------------------------------
Total from investment operations .26 .08 .21 .26 .23
- -----------------------------------------------------------------------------------------------------------
LESS DISTRIBUTIONS:
Dividends from net investment income (.21) (.20) (.19) (.17) (.20)
Tax return of capital (.01) -- -- -- --
- -----------------------------------------------------------------------------------------------------------
Total distributions (.22) (.20) (.19) (.17) (.20)
- -----------------------------------------------------------------------------------------------------------
Net asset value, end of period $4.81 $4.77 $4.89 $4.87 $4.78
- -----------------------------------------------------------------------------------------------------------
RATIOS/SUPPLEMENTAL DATA
Net assets, end of period (in
millions) $1,937 $2,013 $1,774 $1,933 $2,280
- -----------------------------------------------------------------------------------------------------------
Ratio of expenses to average daily
net assets(c),(d) .89%(e) .89%(e) .94%(e) .98%(e) .97%
- -----------------------------------------------------------------------------------------------------------
Ratio of net investment income (loss)
to average daily net assets 4.43% 4.09% 3.67% 3.55% 4.16%
- -----------------------------------------------------------------------------------------------------------
Portfolio turnover rate
(excluding short-term securities) 295% 281% 300% 279% 256%
- -----------------------------------------------------------------------------------------------------------
Total return(f) 5.54% 1.64% 4.38% 5.54% 4.91%
- -----------------------------------------------------------------------------------------------------------
</Table>

(a) For a share outstanding throughout the period. Rounded to the nearest cent.
(b) Per share amount has been calculated using average shares outstanding
method.
(c) Expense ratio is based on total expenses of the Fund after Investment
Manager waiver/reimbursement and before reduction of earnings and bank fee
credits on cash balances.
(d) In addition to the fees and expenses which the Fund bears directly, the
Fund indirectly bears a pro rata share of the fees and expenses of the
acquired funds in which it invests. Such indirect expenses are not included
in the above reported expense ratios.
(e) The Investment Manager and its affiliates waived/reimbursed the Fund for
certain expenses. Had they not done so, the annual ratios of expenses for
Class A would have been 0.97%, 0.99%, 1.02% and 1.00% for the years ended
Aug. 31, 2007, 2006, 2005 and 2004, respectively.
(f) Total return does not reflect payment of a sales charge.

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

RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS 17P

CLASS B

<Table>
<Caption>
PER SHARE INCOME AND CAPITAL CHANGES(a)
FISCAL PERIOD ENDED AUG. 31, 2007 2006 2005 2004 2003

Net asset value, beginning of period $4.77 $4.89 $4.88 $4.78 $4.75
- -----------------------------------------------------------------------------------------------------------
INCOME FROM INVESTMENT OPERATIONS:
Net investment income (loss) .18(b) .16 .15 .14 .16
Net gains (losses) (both realized and
unrealized) .04 (.12) .01 .09 .03
- -----------------------------------------------------------------------------------------------------------
Total from investment operations .22 .04 .16 .23 .19
- -----------------------------------------------------------------------------------------------------------
LESS DISTRIBUTIONS:
Dividends from net investment income (.18) (.16) (.15) (.13) (.16)
Tax return of capital (.00) -- -- -- --
- -----------------------------------------------------------------------------------------------------------
Total distributions (.18) (.16) (.15) (.13) (.16)
- -----------------------------------------------------------------------------------------------------------
Net asset value, end of period $4.81 $4.77 $4.89 $4.88 $4.78
- -----------------------------------------------------------------------------------------------------------
RATIOS/SUPPLEMENTAL DATA
Net assets, end of period (in
millions) $304 $402 $484 $628 $902
- -----------------------------------------------------------------------------------------------------------
Ratio of expenses to average daily
net assets(c),(d) 1.65%(e) 1.65%(e) 1.70%(e) 1.73%(e) 1.73%
- -----------------------------------------------------------------------------------------------------------
Ratio of net investment income (loss)
to average daily net assets 3.66% 3.31% 2.92% 2.78% 3.40%
- -----------------------------------------------------------------------------------------------------------
Portfolio turnover rate
(excluding short-term securities) 295% 281% 300% 279% 256%
- -----------------------------------------------------------------------------------------------------------
Total return(f) 4.74% .88% 3.39% 4.95% 4.12%
- -----------------------------------------------------------------------------------------------------------
</Table>

(a) For a share outstanding throughout the period. Rounded to the nearest cent.
(b) Per share amount has been calculated using average shares outstanding
method.
(c) Expense ratio is based on total expenses of the Fund after Investment
Manager waiver/reimbursement and before reduction of earnings and bank fee
credits on cash balances.
(d) In addition to the fees and expenses which the Fund bears directly, the
Fund indirectly bears a pro rata share of the fees and expenses of the
acquired funds in which it invests. Such indirect expenses are not included
in the above reported expense ratios.
(e) The Investment Manager and its affiliates waived/reimbursed the Fund for
certain expenses. Had they not done so, the annual ratios of expenses for
Class B would have been 1.73%, 1.76%, 1.78% and 1.75% for the years ended
Aug. 31, 2007, 2006, 2005 and 2004, respectively.
(f) Total return does not reflect payment of a sales charge.

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

18P RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS

CLASS C

<Table>
<Caption>
PER SHARE INCOME AND CAPITAL CHANGES(a)
FISCAL PERIOD ENDED AUG. 31, 2007 2006 2005 2004 2003

Net asset value, beginning of period $4.77 $4.90 $4.88 $4.78 $4.75
- -----------------------------------------------------------------------------------------------------------
INCOME FROM INVESTMENT OPERATIONS:
Net investment income (loss) .18(b) .16 .15 .14 .16
Net gains (losses) (both realized and
unrealized) .04 (.13) .02 .09 .03
- -----------------------------------------------------------------------------------------------------------
Total from investment operations .22 .03 .17 .23 .19
- -----------------------------------------------------------------------------------------------------------
LESS DISTRIBUTIONS:
Dividends from net investment income (.18) (.16) (.15) (.13) (.16)
Tax return of capital (.00) -- -- -- --
- -----------------------------------------------------------------------------------------------------------
Total distributions (.18) (.16) (.15) (.13) (.16)
- -----------------------------------------------------------------------------------------------------------
Net asset value, end of period $4.81 $4.77 $4.90 $4.88 $4.78
- -----------------------------------------------------------------------------------------------------------
RATIOS/SUPPLEMENTAL DATA
Net assets, end of period (in
millions) $17 $17 $18 $21 $27
- -----------------------------------------------------------------------------------------------------------
Ratio of expenses to average daily
net assets(c),(d) 1.65%(e) 1.66%(e) 1.70%(e) 1.73%(e) 1.74%
- -----------------------------------------------------------------------------------------------------------
Ratio of net investment income (loss)
to average daily net assets 3.67% 3.31% 2.93% 2.79% 3.34%
- -----------------------------------------------------------------------------------------------------------
Portfolio turnover rate
(excluding short-term securities) 295% 281% 300% 279% 256%
- -----------------------------------------------------------------------------------------------------------
Total return(f) 4.73% .66% 3.60% 4.95% 4.11%
- -----------------------------------------------------------------------------------------------------------
</Table>

(a) For a share outstanding throughout the period. Rounded to the nearest cent.
(b) Per share amount has been calculated using average shares outstanding
method.
(c) Expense ratio is based on total expenses of the Fund after Investment
Manager waiver/reimbursement and before reduction of earnings and bank fee
credits on cash balances.
(d) In addition to the fees and expenses which the Fund bears directly, the
Fund indirectly bears a pro rata share of the fees and expenses of the
acquired funds in which it invests. Such indirect expenses are not included
in the above reported expense ratios.
(e) The Investment Manager and its affiliates waived/reimbursed the Fund for
certain expenses. Had they not done so, the annual ratios of expenses for
Class C would have been 1.73%, 1.76%, 1.79% and 1.75% for the years ended
Aug. 31, 2007, 2006, 2005 and 2004, respectively.
(f) Total return does not reflect payment of a sales charge.

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

RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS 19P

CLASS I

<Table>
<Caption>
PER SHARE INCOME AND CAPITAL CHANGES(a)
FISCAL PERIOD ENDED AUG. 31, 2007 2006 2005 2004(B)

Net asset value, beginning of period $4.78 $4.89 $4.88 $4.91
- -----------------------------------------------------------------------------------------------------------
INCOME FROM INVESTMENT OPERATIONS:
Net investment income (loss) .23(c) .21 .20 .11
Net gains (losses) (both realized and
unrealized) .04 (.11) .02 (.04)
- -----------------------------------------------------------------------------------------------------------
Total from investment operations .27 .10 .22 .07
- -----------------------------------------------------------------------------------------------------------
LESS DISTRIBUTIONS:
Dividends from net investment income (.22) (.21) (.21) (.10)
Tax return of capital (.01) -- -- --
- -----------------------------------------------------------------------------------------------------------
Total distributions (.23) (.21) (.21) (.10)
- -----------------------------------------------------------------------------------------------------------
Net asset value, end of period $4.82 $4.78 $4.89 $4.88
- -----------------------------------------------------------------------------------------------------------
RATIOS/SUPPLEMENTAL DATA
Net assets, end of period (in
millions) $386 $276 $-- $--
- -----------------------------------------------------------------------------------------------------------
Ratio of expenses to average daily
net assets(d),(e) .54%(f) .54%(f) .60% .59%(g)
- -----------------------------------------------------------------------------------------------------------
Ratio of net investment income (loss)
to average daily net assets 4.80% 4.59% 4.01% 3.13%(g)
- -----------------------------------------------------------------------------------------------------------
Portfolio turnover rate
(excluding short-term securities) 295% 281% 300% 279%
- -----------------------------------------------------------------------------------------------------------
Total return(h) 5.90% 2.19% 4.53% 1.43%(i)
- -----------------------------------------------------------------------------------------------------------
</Table>

(a) For a share outstanding throughout the period. Rounded to the nearest cent.
(b) For the period from March 4, 2004 (inception date) to Aug. 31, 2004.
(c) Per share amount has been calculated using average shares outstanding
method.
(d) Expense ratio is based on total expenses of the Fund after Investment
Manager waiver/reimbursement and before reduction of earnings and bank fee
credits on cash balances.
(e) In addition to the fees and expenses which the Fund bears directly, the
Fund indirectly bears a pro rata share of the fees and expenses of the
acquired funds in which it invests. Such indirect expenses are not included
in the above reported expense ratios.
(f) The Investment Manager and its affiliates waived/reimbursed the Fund for
certain expenses. Had they not done so, the annual ratios of expenses for
Class I would have been 0.56% and 0.55% for the years ended Aug. 31, 2007
and 2006, respectively.
(g) Adjusted to an annual basis.
(h) Total return does not reflect payment of a sales charge.
(i) Not annualized.

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

20P RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS

CLASS R2

<Table>
<Caption>
PER SHARE INCOME AND CAPITAL CHANGES(a)
FISCAL PERIOD ENDED AUG. 31, 2007(B)

Net asset value, beginning of period $4.81
- -----------------------------------------------------------------------------------------------------------
INCOME FROM INVESTMENT OPERATIONS:
Net investment income (loss) .14(c)
Net gains (losses) (both realized and
unrealized) (.02)
- -----------------------------------------------------------------------------------------------------------
Total from investment operations .12
- -----------------------------------------------------------------------------------------------------------
LESS DISTRIBUTIONS:
Dividends from net investment income (.13)
Tax return of capital (.00)
- -----------------------------------------------------------------------------------------------------------
Total distributions (.13)
- -----------------------------------------------------------------------------------------------------------
Net asset value, end of period $4.80
- -----------------------------------------------------------------------------------------------------------
RATIOS/SUPPLEMENTAL DATA
Net assets, end of period (in
millions) $--
- -----------------------------------------------------------------------------------------------------------
Ratio of expenses to average daily
net assets(d),(e) 1.32%(f)
- -----------------------------------------------------------------------------------------------------------
Ratio of net investment income (loss)
to average daily net assets 4.06%(f)
- -----------------------------------------------------------------------------------------------------------
Portfolio turnover rate
(excluding short-term securities) 295%
- -----------------------------------------------------------------------------------------------------------
Total return(g) 2.70%(h)
- -----------------------------------------------------------------------------------------------------------
</Table>

(a) For a share outstanding throughout the period. Rounded to the nearest cent.
(b) For the period from Dec. 11, 2006 (inception date) to Aug. 31, 2007.
(c) Per share amount has been calculated using average shares outstanding
method.
(d) Expense ratio is based on total expenses of the Fund before reduction of
earnings and bank fee credits on cash balances.
(e) In addition to the fees and expenses which the Fund bears directly, the
Fund indirectly bears a pro rata share of the fees and expenses of the
acquired funds in which it invests. Such indirect expenses are not included
in the above reported expense ratios.
(f) Adjusted to an annual basis.
(g) Total return does not reflect payment of a sales charge.
(h) Not annualized.

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

RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS 21P

CLASS R3

<Table>
<Caption>
PER SHARE INCOME AND CAPITAL CHANGES(a)
FISCAL PERIOD ENDED AUG. 31, 2007(B)

Net asset value, beginning of period $4.81
- -----------------------------------------------------------------------------------------------------------
INCOME FROM INVESTMENT OPERATIONS:
Net investment income (loss) .15(c)
Net gains (losses) (both realized and
unrealized) (.02)
- -----------------------------------------------------------------------------------------------------------
Total from investment operations .13
- -----------------------------------------------------------------------------------------------------------
LESS DISTRIBUTIONS:
Dividends from net investment income (.14)
Tax return of capital (.00)
- -----------------------------------------------------------------------------------------------------------
Total distributions (.14)
- -----------------------------------------------------------------------------------------------------------
Net asset value, end of period $4.80
- -----------------------------------------------------------------------------------------------------------
RATIOS/SUPPLEMENTAL DATA
Net assets, end of period (in
millions) $--
- -----------------------------------------------------------------------------------------------------------
Ratio of expenses to average daily
net assets(d),(e) 1.06%(f)
- -----------------------------------------------------------------------------------------------------------
Ratio of net investment income (loss)
to average daily net assets 4.33%(f)
- -----------------------------------------------------------------------------------------------------------
Portfolio turnover rate
(excluding short-term securities) 295%
- -----------------------------------------------------------------------------------------------------------
Total return(g) 2.90%(h)
- -----------------------------------------------------------------------------------------------------------
</Table>

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

22P RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS

CLASS R4*

<Table>
<Caption>
PER SHARE INCOME AND CAPITAL CHANGES(a)
FISCAL PERIOD ENDED AUG. 31, 2007 2006 2005 2004 2003

Net asset value, beginning of period $4.77 $4.89 $4.88 $4.78 $4.75
- -----------------------------------------------------------------------------------------------------------
INCOME FROM INVESTMENT OPERATIONS:
Net investment income (loss) .22(b) .20 .19 .18 .21
Net gains (losses) (both realized and
unrealized) .04 (.12) .02 .10 .03
- -----------------------------------------------------------------------------------------------------------
Total from investment operations .26 .08 .21 .28 .24
- -----------------------------------------------------------------------------------------------------------
LESS DISTRIBUTIONS:
Dividends from net investment income (.22) (.20) (.20) (.18) (.21)
Tax return of capital (.01) -- -- -- --
- -----------------------------------------------------------------------------------------------------------
Total distributions (.23) (.20) (.20) (.18) (.21)
- -----------------------------------------------------------------------------------------------------------
Net asset value, end of period $4.80 $4.77 $4.89 $4.88 $4.78
- -----------------------------------------------------------------------------------------------------------
RATIOS/SUPPLEMENTAL DATA
Net assets, end of period (in
millions) $78 $173 $202 $203 $268
- -----------------------------------------------------------------------------------------------------------
Ratio of expenses to average daily
net assets(c),(d) .73%(e) .73%(e) .78%(e) .81%(e) .81%
- -----------------------------------------------------------------------------------------------------------
Ratio of net investment income (loss)
to average daily net assets 4.53% 4.24% 3.85% 3.70% 4.34%
- -----------------------------------------------------------------------------------------------------------
Portfolio turnover rate
(excluding short-term securities) 295% 281% 300% 279% 256%
- -----------------------------------------------------------------------------------------------------------
Total return(f) 5.49% 1.81% 4.34% 5.92% 5.08%
- -----------------------------------------------------------------------------------------------------------
</Table>

* Effective Dec. 11, 2006, Class Y was renamed Class R4.
(a) For a share outstanding throughout the period. Rounded to the nearest cent.
(b) Per share amount has been calculated using average shares outstanding
method.
(c) Expense ratio is based on total expenses of the Fund after Investment
Manager waiver/reimbursement and before reduction of earnings and bank fee
credits on cash balances.
(d) In addition to the fees and expenses which the Fund bears directly, the
Fund indirectly bears a pro rata share of the fees and expenses of the
acquired funds in which it invests. Such indirect expenses are not included
in the above reported expense ratios.
(e) The Investment Manager and its affiliates waived/reimbursed the Fund for
certain expenses. Had they not done so, the annual ratios of expenses for
Class R4 would have been 0.83%, 0.82%, 0.86% and 0.83% for the years ended
Aug. 31, 2007, 2006, 2005 and 2004, respectively.
(f) Total return does not reflect payment of a sales charge.

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

RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS 23P

CLASS R5

<Table>
<Caption>
PER SHARE INCOME AND CAPITAL CHANGES(a)
FISCAL PERIOD ENDED AUG. 31, 2007(B)

Net asset value, beginning of period $4.81
- -----------------------------------------------------------------------------------------------------------
INCOME FROM INVESTMENT OPERATIONS:
Net investment income (loss) .17(c)
Net gains (losses) (both realized and
unrealized) (.02)
- -----------------------------------------------------------------------------------------------------------
Total from investment operations .15
- -----------------------------------------------------------------------------------------------------------
LESS DISTRIBUTIONS:
Dividends from net investment income (.16)
Tax return of capital (.00)
- -----------------------------------------------------------------------------------------------------------
Total distributions (.16)
- -----------------------------------------------------------------------------------------------------------
Net asset value, end of period $4.80
- -----------------------------------------------------------------------------------------------------------
RATIOS/SUPPLEMENTAL DATA
Net assets, end of period (in
millions) $--
- -----------------------------------------------------------------------------------------------------------
Ratio of expenses to average daily
net assets(d),(e),(f) .57%(g)
- -----------------------------------------------------------------------------------------------------------
Ratio of net investment income (loss)
to average daily net assets 4.81%(g)
- -----------------------------------------------------------------------------------------------------------
Portfolio turnover rate
(excluding short-term securities) 295%
- -----------------------------------------------------------------------------------------------------------
Total return(h) 3.25%(i)
- -----------------------------------------------------------------------------------------------------------
</Table>

(a) For a share outstanding throughout the period. Rounded to the nearest cent.
(b) For the period from Dec. 11, 2006 (inception date) to Aug. 31, 2007.
(c) Per share amount has been calculated using average shares outstanding
method.
(d) Expense ratio is based on total expenses of the Fund after Investment
Manager waiver/reimbursement and before reduction of earnings and bank fee
credits on cash balances.
(e) In addition to the fees and expenses which the Fund bears directly, the
Fund indirectly bears a pro rata share of the fees and expenses of the
acquired funds in which it invests. Such indirect expenses are not included
in the above reported expense ratios.
(f) The Investment Manager and its affiliates waived/reimbursed the Fund for
certain expenses. Had they not done so, the annual ratio of expenses for
Class R5 would have been 0.59% for the period ended Aug. 31, 2007.
(g) Adjusted to an annual basis.
(h) Total return does not reflect payment of a sales charge.
(i) Not annualized.

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

24P RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS

CLASS W

<Table>
<Caption>
PER SHARE INCOME AND CAPITAL CHANGES(a)
FISCAL PERIOD ENDED AUG. 31, 2007(B)

Net asset value, beginning of period $4.82
- -----------------------------------------------------------------------------------------------------------
INCOME FROM INVESTMENT OPERATIONS:
Net investment income (loss) .15(c)
- -----------------------------------------------------------------------------------------------------------
LESS DISTRIBUTIONS:
Dividends from net investment income (.16)
Tax return of capital (.00)
- -----------------------------------------------------------------------------------------------------------
Total distributions (.16)
- -----------------------------------------------------------------------------------------------------------
Net asset value, end of period $4.81
- -----------------------------------------------------------------------------------------------------------
RATIOS/SUPPLEMENTAL DATA
Net assets, end of period (in
millions) $223
- -----------------------------------------------------------------------------------------------------------
Ratio of expenses to average daily
net assets(d),(e),(f) .97%(g)
- -----------------------------------------------------------------------------------------------------------
Ratio of net investment income (loss)
to average daily net assets 4.32%(g)
- -----------------------------------------------------------------------------------------------------------
Portfolio turnover rate
(excluding short-term securities) 295%
- -----------------------------------------------------------------------------------------------------------
Total return(h) 2.71%(i)
- -----------------------------------------------------------------------------------------------------------
</Table>

(a) For a share outstanding throughout the period. Rounded to the nearest cent.
(b) For the period from Dec. 1, 2006 (inception date) to Aug. 31, 2007.
(c) Per share amount has been calculated using average shares outstanding
method.
(d) Expense ratio is based on total expenses of the Fund after Investment
Manager waiver/reimbursement and before reduction of earnings and bank fee
credits on cash balances.
(e) In addition to the fees and expenses which the Fund bears directly, the
Fund indirectly bears a pro rata share of the fees and expenses of the
acquired funds in which it invests. Such indirect expenses are not included
in the above reported expense ratios.
(f) The Investment Manager and its affiliates waived/reimbursed the Fund for
certain expenses. Had they not done so, the annual ratio of expenses for
Class W would have been 0.98% for the period ended Aug. 31, 2007.
(g) Adjusted to an annual basis.
(h) Total return does not reflect payment of a sales charge.
(i) Not annualized.

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

RIVERSOURCE DIVERSIFIED BOND FUND -- 2007 PROSPECTUS 25P

BUYING AND SELLING SHARES

The RiverSource funds are available through broker-dealers, certain 401(k) or
other qualified and nonqualified plans, banks, or other financial intermediaries
or institutions (financial institutions). THESE FINANCIAL INSTITUTIONS MAY
CHARGE YOU ADDITIONAL FEES FOR THE SERVICES THEY PROVIDE AND THEY MAY HAVE
DIFFERENT POLICIES NOT DESCRIBED IN THIS PROSPECTUS. Some policy differences may
include different minimum investment amounts, exchange privileges, fund choices
and cutoff times for investments. Additionally, recordkeeping, transaction
processing and payments of distributions relating to your account may be
performed by the financial institutions through which shares are held. Since the
fund may not have a record of your transactions, you should always contact the
financial institution through which you purchased the fund to make changes to or
give instructions concerning your account or to obtain information about your
account. The fund, the distributor and the transfer agent are not responsible
for the failure of one of these financial institutions to carry out its
obligations to its customers.

DESCRIPTION OF SHARE CLASSES

INVESTMENT OPTIONS -- CLASSES OF SHARES

The RiverSource funds offer different classes of shares. There are differences
among the fees and expenses for each class. See the "Fees and Expenses" table
for more information. Not everyone is eligible to buy every class. After
determining which classes you are eligible to buy, decide which class best suits
your needs. Your financial institution can help you with this decision. The
following table shows the key features of each class. (The cover of this
prospectus indicates which classes are currently offered for this Fund.)

INVESTMENT OPTIONS SUMMARY

See the "Fees and Expenses" table to determine which classes are offered by this
fund.

<Table>
<Caption>
CONTINGENT PLAN
INITIAL DEFERRED SALES DISTRIBUTION AND ADMINISTRATION
AVAILABILITY SALES CHARGE CHARGE (CDSC) SERVICE FEE(A) FEE
- -------------------------------------------------------------------------------------------------------------

Class A Available to Yes. Payable at No. Yes. No.
all investors. time of purchase. 0.25%
Lower sales
charge for larger
investments.
- -------------------------------------------------------------------------------------------------------------
Class Available to No. Entire Maximum 5% CDSC during Yes. No.
B(b) all investors. purchase price is the first year decreasing 1.00%
invested in to 0% after six years.
shares of the
fund.
- -------------------------------------------------------------------------------------------------------------
</Table>

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

S.1 S-6400-6

<Table>
<Caption>
INVESTMENT OPTIONS SUMMARY (CONTINUED)
CONTINGENT PLAN
INITIAL DEFERRED SALES DISTRIBUTION AND ADMINISTRATION
AVAILABILITY SALES CHARGE CHARGE (CDSC) SERVICE FEE(A) FEE
- -------------------------------------------------------------------------------------------------------------

Class C Available to No. Entire 1% CDSC may apply if you Yes. No.
all investors. purchase price is sell shares within one 1.00%
invested in year after purchase.
shares of the
fund.
- -------------------------------------------------------------------------------------------------------------
Class I Limited to No. No. No. No.
qualifying
institutional
investors.
- -------------------------------------------------------------------------------------------------------------
Class R2 Limited to No. No. Yes. Yes.
qualifying 0.50% 0.25%
institutional
investors.
- -------------------------------------------------------------------------------------------------------------
Class R3 Limited to No. No. Yes. Yes.
qualifying 0.25% 0.25%
institutional
investors.
- -------------------------------------------------------------------------------------------------------------
Class R4 Limited to No. No. No. Yes.
qualifying 0.25%
institutional
investors.
- -------------------------------------------------------------------------------------------------------------
Class R5 Limited to No. No. No. No.
qualifying
institutional
investors.
- -------------------------------------------------------------------------------------------------------------
Class W Limited to No. No. Yes. No.
qualifying 0.25%
discretionary
managed accounts.
- -------------------------------------------------------------------------------------------------------------
</Table>

(a) For Class A, Class B, Class C, Class R2, Class R3 and Class W shares, each
fund has adopted a plan under Rule 12b-1 of the Investment Company Act of
1940, as amended, that allows it to pay distribution and shareholder
servicing-related expenses for the sale of shares. Because these fees are
paid out of a fund's assets on an on-going basis, over time these fees will
increase the cost of your investment and may cost you more than paying
other types of distribution (sales) or servicing charges.
(b) See "Buying and Selling Shares, Sales Charges, Class B and Class
C -- contingent deferred sales charge alternative" for more information on
the timing of conversion of Class B shares to Class A shares. Timing will
vary depending on the date of your original purchase of the Class B shares.

DISTRIBUTION AND SERVICE FEES

The distribution and shareholder servicing fees for Class A, Class B, Class C,
Class R2, Class R3 and Class W are subject to the requirements of Rule 12b-1
under the Investment Company Act of 1940, as amended, and are used to reimburse
the distributor for certain expenses it incurs in connection with distributing a
fund's shares and providing services to fund shareholders. These expenses
include payment of distribution and shareholder servicing fees to financial
institutions that sell shares of the fund, up to 0.50% of the average daily net
assets of Class R2 shares sold and held through them and up to 0.25% of the
average daily net assets of Class A, Class B, Class C, Class R3 and Class W
shares sold and held through them. For Class A, Class B, Class R2, Class R3 and
Class W shares, the distributor begins to pay these fees immediately after

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

S.2

purchase. For Class C shares, the distributor begins to pay these fees one year
after purchase. Financial institutions also receive distribution fees up to
0.75% of the average daily net assets of Class C shares sold and held through
them, which the distributor begins to pay one year after purchase.

For Class B shares, and, for the first year after sale only, for Class C shares,
the fund's distributor retains the distribution fee of up to 0.75% in order to
finance the payment of sales commissions to financial institutions that sell
Class B shares, and to pay for other distribution related expenses. Financial
institutions may compensate their financial advisors with the shareholder
servicing and distribution fees paid to them by the distributor.

PLAN ADMINISTRATION FEE

Class R2, Class R3 and Class R4 pay an annual plan administration services fee
for the provision of various administrative, recordkeeping, communication and
educational services. The fee for Class R2, Class R3 and Class R4 is equal on an
annual basis to 0.25% of assets attributable to the respective class.

DETERMINING WHICH CLASS OF SHARES TO PURCHASE

CLASS A, CLASS B AND CLASS C SHARES.

If your investments in RiverSource funds total $100,000 or more, Class A shares
may be the better option because the sales charge is reduced for larger
purchases.

If you invest less than $100,000, consider how long you plan to hold your
shares. Class B shares have a higher annual distribution fee than Class A shares
and a CDSC for six years. Class B shares convert to Class A shares in the ninth
year of ownership. Class B shares purchased through reinvested dividends and
distributions also will convert to Class A shares in the same proportion as the
other Class B shares.

Class C shares also have a higher annual distribution fee than Class A shares.
Class C shares have no sales charge if you hold the shares for longer than one
year. Unlike Class B shares, Class C shares do not convert to Class A. As a
result, you will pay a distribution fee for as long as you hold Class C shares.
If you choose a deferred sales charge option (Class B or Class C), you should
consider the length of time you intend to hold your shares. To help you
determine which investment is best for you, consult your financial institution.

CLASS I SHARES.

The following eligible investors may purchase Class I shares:

- - Any fund distributed by RiverSource Distributors, Inc., if the fund seeks to
achieve its investment objective by investing primarily in shares of the fund
and other RiverSource funds.

Class I shares may be purchased, sold or exchanged only through the distributor
or an authorized financial institution.

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

S.3

CLASS R SHARES.

The following eligible institutional investors may purchase Class R2, Class R3,
Class R4 and Class R5 shares:

- - Qualified employee benefit plans.

- - Trust companies or similar institutions, and charitable organizations that
meet the definition in Section 501(c)(3) of the Internal Revenue Code.

- - Non-qualified deferred compensation plans whose participants are included in a
qualified employee benefit plan described above.

- - State sponsored college savings plans established under Section 529 of the
Internal Revenue Code.

- - Health Savings Accounts (HSAs) created pursuant to public law 108-173.

Additionally, if approved by the distributor, the following eligible
institutional investors may purchase Class R5 shares:

- - Institutional or corporate accounts above a threshold established by the
distributor (currently $1 million per fund or $10 million in all RiverSource
funds).

- - Bank Trusts departments.

Class R shares generally are not available to retail non-retirement accounts,
traditional and Roth IRAs, Coverdell Educational Savings Accounts, SEPs, SAR-
SEPs, SIMPLE IRAs and individual 403(b) plans.

Class R shares may be purchased, sold or exchanged only through the distributor
or an authorized financial institution.

CLASS W SHARES.

The following eligible investors may purchase Class W shares:

- - Investors purchasing through authorized investment programs managed by
investment professionals, including discretionary managed account programs.

Class W shares may be purchased, sold or exchanged only through the distributor
or an authorized financial institution.

Shares originally purchased in a discretionary managed account may continue to
be held in Class W outside of a discretionary managed account, but no additional
Class W purchases may be made and no exchanges to Class W shares of another fund
may be made outside of a discretionary managed account.

IN ADDITION, FOR CLASS I, CLASS R AND CLASS W SHARES, THE DISTRIBUTOR, IN ITS
SOLE DISCRETION, MAY ACCEPT INVESTMENTS FROM OTHER PURCHASERS NOT LISTED ABOVE.

For more information, see the SAI.

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

S.4

SALES CHARGES

CLASS A -- INITIAL SALES CHARGE ALTERNATIVE:

Your purchase price for Class A shares is generally the net asset value (NAV)
plus a front-end sales charge. The distributor receives the sales charge and
re-allows a portion of the sales charge to the financial institution through
which you purchased the shares. The distributor retains the balance of the sales
charge. Sales charges vary depending on the amount of your purchase.

SALES CHARGE* FOR CLASS A SHARES

<Table>
<Caption>
MAXIMUM REALLOWANCE
AS A % OF AS A % OF AS A % OF
TOTAL MARKET VALUE PURCHASE PRICE** NET AMOUNT INVESTED PURCHASE PRICE
- --------------------------------------------------------------------------------------------

Up to $49,999 4.75% 4.99% 4.00%
$50,000 -- $99,999 4.25 4.44 3.50
$100,000 -- $249,999 3.50 3.63 3.00
$250,000 -- $499,999 2.50 2.56 2.15
$500,000 -- $999,999 2.00 2.04 1.75
$1,000,000 or more 0.00 0.00 0.00***
</Table>

* Because of rounding in the calculation of the offering price, the portion of
the sales charge retained by the distributor may vary and the actual sales
charge you pay may be more or less than the sales charge calculated using
these percentages.
** Purchase price includes the sales charge.
***Although there is no sales charge for purchases with a total market value
over $1,000,000, and therefore no re-allowance, the distributor may pay a
financial institution the following: a sales commission of up to 1.00% for a
sale with a total market value of $1,000,000 to $2,999,999; a sales
commission up to 0.50% for a sale of $3,000,000 to $9,999,999; and a sales
commission up to 0.25% for a sale of $10,000,000 or more.

INITIAL SALES CHARGE -- RIGHTS OF ACCUMULATION. You may be able to reduce the
sales charge on Class A shares, based on the combined market value of your
accounts. The current market values of the following investments are eligible to
be added together for purposes of determining the sales charge on your purchase:

- - Your current investment in a fund; and

- - Previous investments you and members of your primary household group have made
in Class A, Class B or Class C shares in the fund and other RiverSource funds,
provided your investment was subject to a sales charge. Your primary household
group consists of you, your spouse or domestic partner and your unmarried
children under age 21 sharing a mailing address.

The following accounts are eligible to be included in determining the sales
charge on your purchase:

- - Individual or joint accounts;

- - Roth and traditional IRAs, SEPs, SIMPLEs and TSCAs, provided they are invested
in Class A, Class B or Class C shares that were subject to a sales charge;

- --------------------------------------------------------------------------------
S.5

- - UGMA/UTMA accounts for which you, your spouse, or your domestic partner is
parent or guardian of the minor child;

- - Revocable trust accounts for which you or a member of your primary household
group, individually, is the beneficial owner/grantor;

- - Accounts held in the name of your, your spouse's, or your domestic partner's
sole proprietorship or single owner limited liability company or S
corporation; and

- - Qualified retirement plan assets, provided that you are the sole owner of the
business sponsoring the plan, are the sole participant (other than a spouse)
in the plan, and have no intention of adding participants to the plan.

The following accounts are not eligible to be included in determining the sales
charge on your purchase:

- - Accounts of pension and retirement plans with multiple participants, such as
401(k) plans (which are combined to reduce the sales charge for the entire
pension or retirement plan and therefore are not used to reduce the sales
charge for your individual accounts);

- - Investments in Class A shares where the sales charge is waived, for example,
purchases through wrap accounts;

- - Investments in Class D, Class E, Class I, Class R2, Class R3, Class R4, Class
R5, Class W or Class Y shares;

- - Investments in 529 plans, donor advised funds, variable annuities, variable
life insurance products, wrap accounts or managed separate accounts; and

- - Charitable and irrevocable trust accounts.

If you purchase RiverSource fund shares through different financial
institutions, and you want to include those assets toward a reduced sales
charge, you must inform your financial institution in writing about the other
accounts when placing your purchase order. Contact your financial institution to
determine what information is required.

Unless you provide your financial institution in writing with information about
all of the accounts that may count toward a sales charge reduction, there can be
no assurance that you will receive all of the reductions for which you may be
eligible. You should request that your financial institution provide this
information to the fund when placing your purchase order.

For more information on rights of accumulation, please see the SAI.

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

S.6

INITIAL SALES CHARGE -- LETTER OF INTENT (LOI). Generally, if you intend to
invest $50,000 or more over a period of 13 months or less, you may be able to
reduce the front-end sales charges for investments in Class A shares by
completing and filing a LOI form. The LOI becomes effective only after the form
is processed in good order by the fund. An LOI can be backdated up to a maximum
of 90 days. If the LOI is backdated, you may include prior investments in Class
A shares that were charged a front-end sales load toward the LOI commitment
amount. If the LOI is backdated, the 13-month period begins on the date of the
earliest purchase included in the LOI.

Holdings More than 90 Days Old. Purchases made more than 90 days before your LOI
is processed by the fund will not be counted toward the commitment amount of the
LOI and cannot be used as the starting point for the LOI. While these purchases
cannot be included in an LOI, they may help you obtain a reduced sales charge on
future purchases as described in "Initial Sales Charge -- Rights of
Accumulation."

Notification Obligation. You must request the reduced sales charge when you buy
shares. If you do not complete and file the LOI form, or do not request the
reduced sales charge at the time of purchase, you will not be eligible for the
reduced sales charge. You should request that your financial institution provide
this information to the fund when placing your purchase order. For more details
on LOIs, please contact your financial institution or see the SAI.

INITIAL SALES CHARGE -- WAIVERS OF THE SALES CHARGE FOR CLASS A SHARES. Sales
charges do not apply to:

- - current or retired Board members, officers or employees of RiverSource funds
or RiverSource Investments or its affiliates, their spouses or domestic
partners, children, parents and their spouse's or domestic partner's parents.

- - current or retired Ameriprise Financial Services, Inc. (Ameriprise Financial
Services) financial advisors, employees of financial advisors, their spouses
or domestic partners, children, parents and their spouse's or domestic
partner's parents.

- - registered representatives and other employees of financial institutions
having a selling agreement with the distributor, including their spouses,
domestic partners, children, parents and their spouse's or domestic partner's
parents.

- - portfolio managers employed by subadvisers of the RiverSource funds, including
their spouses or domestic partners, children, parents and their spouse's or
domestic partner's parents.

- - qualified employee benefit plans offering participants daily access to
RiverSource funds. Eligibility must be determined in advance. For assistance,
please contact your financial institution.

- - direct rollovers from qualified employee benefit plans, provided that the
rollover involves a transfer of Class R or Class Y shares in a fund to Class A
shares in the same fund.

- --------------------------------------------------------------------------------
S.7

- - purchases made:

- with dividend or capital gain distributions from a fund or from the same
class of another RiverSource fund;

- through or under a wrap fee product or other investment product sponsored by
a financial institution having a selling agreement with the distributor;

- through state sponsored college savings plans established under Section 529
of the Internal Revenue Code;

- through bank trust departments.

- - shareholders whose original purchase was in a Strategist fund merged into a
RiverSource fund in 2000.

The distributor may, in its sole discretion, authorize the waiver of sales
charges for additional purchases or categories of purchases. Policies related to
reducing or waiving the sales charge may be modified or withdrawn at any time.

Unless you provide your financial institution with information in writing about
all of the factors that may count toward a waiver of the sales charge, there can
be no assurance that you will receive all of the waivers for which you may be
eligible. You should request that your financial institution provide this
information to the fund when placing your purchase order.

Because the current prospectus is available on RiverSource Investment's website
free of charge, RiverSource Investments does not disclose this information
separately on the website.

CLASS B AND CLASS C -- CONTINGENT DEFERRED SALES CHARGE ALTERNATIVE

FOR CLASS B, the CDSC is based on the sale amount and the number of years
between purchase and sale. The following table shows how CDSC percentages on
sales decline:

<Table>
<Caption>
IF THE SALE IS MADE DURING THE: THE CDSC PERCENTAGE RATE IS:*

First year 5%
Second year 4%
Third year 4%
Fourth year 3%
Fifth year 2%
Sixth year 1%
Seventh or eighth year 0%
</Table>

* Because of rounding in the calculation, the portion of the CDSC retained by
the distributor may vary and the actual CDSC you pay may be more or less than
the CDSC calculated using these percentages.

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

S.8

Although there is no front-end sales charge when you buy Class B shares, the
distributor pays a sales commission of 4% to financial institutions that sell
Class B shares. A portion of this commission may, in turn, be paid to your
financial advisor. The distributor receives any CDSC imposed when you sell your
Class B shares.

Purchases made prior to May 21, 2005 age on a calendar year basis. Purchases
made beginning May 21, 2005 age on a daily basis. For example, a purchase made
on Nov. 12, 2004 completed its first year on Dec. 31, 2004 under calendar year
aging. However, a purchase made on Nov. 12, 2005 completed its first year on
Nov. 11, 2006 under daily aging.

Class B shares purchased prior to May 21, 2005 will convert to Class A shares in
the ninth calendar year of ownership. Class B shares purchased beginning May 21,
2005 will convert to Class A shares one month after the completion of the eighth
year of ownership.

FOR CLASS C, a 1% CDSC may be charged if you sell your shares within one year
after purchase. Although there is no front-end sales charge when you buy Class C
shares, the distributor pays a sales commission of 1% to financial institutions
that sell Class C shares. A portion of this commission may, in turn, be paid to
your financial advisor. The distributor receives any CDSC imposed when you sell
your Class C shares.

For both Class B and Class C, if the amount you sell causes the value of your
investment to fall below the cost of the shares you have purchased, the CDSC
will be based on the lower of the cost of those shares purchased or market
value. Because the CDSC is imposed only on sales that reduce your total purchase
payments, you do not have to pay a CDSC on any amount that represents
appreciation in the value of your shares, income earned by your shares, or
capital gains. In addition, the CDSC on your sale, if any, will be based on your
oldest purchase payment. The CDSC on the next amount sold will be based on the
next oldest purchase payment.

EXAMPLE

Assume you had invested $10,000 in Class B shares and that your investment had
appreciated in value to $12,000 after 3 1/2 years, including reinvested
dividends and capital gain distributions. You could sell up to $2,000 worth of
shares without paying a CDSC ($12,000 current value less $10,000 purchase
amount). If you sold $2,500 worth of shares, the CDSC would apply to the $500
representing part of your original purchase price. The CDSC rate would be 3%
because the sale was made during the fourth year after the purchase.

CDSC -- WAIVERS OF THE CDSC FOR CLASS B SHARES. The CDSC will be waived on sales
of shares:
- - in the event of the shareholder's death;

- - held in trust for an employee benefit plan; or

- --------------------------------------------------------------------------------
S.9

- - held in IRAs or certain qualified plans, such as Keogh plans, tax-sheltered
custodial accounts or corporate pension plans, provided that the shareholder
is:

- at least 59 1/2 years old AND

- taking a retirement distribution (if the sale is part of a transfer to an
IRA or qualified plan, or a custodian-to-custodian transfer, the CDSC will
not be waived) OR

- selling under an approved substantially equal periodic payment arrangement.

CDSC -- WAIVERS OF THE CDSC FOR CLASS C SHARES. The CDSC will be waived on sales
of shares in the event of the shareholder's death.

CLASS I, CLASS R2, CLASS R3, CLASS R4, CLASS R5 AND CLASS W -- NO SALES CHARGE.
For Class I, Class R2, Class R3, Class R4, Class R5 and Class W there is no
initial sales charge or CDSC.

OPENING AN ACCOUNT

Financial institutions are required by law to obtain certain personal
information from each person who opens an account in order to verify the
identity of the person. As a result, when you open an account you will be asked
to provide your name, permanent street address, date of birth, and Social
Security or Employer Identification number. You may also be asked for other
identifying documents or information. If you do not provide this information,
the financial institution through which you are investing in the fund may not be
able to open an account for you. If the financial institution through which you
are investing in the fund is unable to verify your identity, your account may be
closed, or other steps may be taken, as deemed appropriate.

When you buy shares, your order will be priced at the next NAV calculated after
your order is accepted by the fund or an authorized financial institution.

Your financial institution may establish and maintain your account directly or
it may establish and maintain your account with the distributor. The distributor
may appoint servicing agents to accept purchase orders and to accept exchange
(and sale) orders on its behalf. Accounts maintained by the distributor will be
supported by the fund's transfer agent.

METHODS OF PURCHASING SHARES

These methods of purchasing shares apply to Class A, Class B, and Class C
shares.

THROUGH AN ACCOUNT ESTABLISHED WITH YOUR FINANCIAL INSTITUTION

ALL REQUESTS The financial institution through which you buy shares may
have different policies not described in this prospectus,
including different minimum investment amounts and minimum
account balances.
- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------
S.10

METHODS OF PURCHASING SHARES (CONTINUED)

THROUGH AN ACCOUNT ESTABLISHED WITH THE FUND

BY MAIL The financial institution through which you buy shares may
establish an account directly with the fund. To establish an
account in this fashion, complete a RiverSource funds
account application with your financial advisor or
investment professional, and mail the account application to
the address below. Account applications may be requested by
calling (888) 791-3380. Make your check payable to the fund.
The fund does not accept cash, credit card convenience
checks, money orders, traveler's checks, starter checks,
third or fourth party checks, or other cash equivalents.

Mail your check and completed application to:

REGULAR MAIL RIVERSOURCE INVESTMENTS (FUNDS)
P.O. BOX 8041
BOSTON, MA 02266-8041

EXPRESS MAIL RIVERSOURCE INVESTMENTS (FUNDS)
C/O BFDS
30 DAN ROAD
CANTON, MA 02021-2809

If you already have an account, include your name, account
number and the name of the fund and class of shares along
with your check. You can make scheduled investments in the
fund by moving money from your checking account or savings
account. See the Minimum Investment and Account Balance
chart below for more information regarding scheduled
investment plans.
- --------------------------------------------------------------------------------

BY WIRE OR ACH Fund shares purchased through the distributor may be paid
for by federal funds wire. Before sending a wire, call (888)
791-3380 to notify the distributor of the wire and to
receive further instructions.

If you are establishing an account with a wire purchase, you
are required to send a signed account application to the
address above. Please include the wire control number or
your new account number on the application.

Your bank or financial institution may charge additional
fees for wire transactions.
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------

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

S.11

METHODS OF PURCHASING SHARES (CONTINUED)

THROUGH AN ACCOUNT ESTABLISHED WITH THE FUND (CONT.)

BY EXCHANGE Call (888) 791-3380 or send signed written instructions to
the address above.
- --------------------------------------------------------------------------------

MINIMUM INVESTMENT AND ACCOUNT BALANCE

<Table>
<Caption>
RIVERSOURCE ABSOLUTE
RETURN CURRENCY
AND INCOME FUND
FOR ALL FUNDS, RIVERSOURCE FLOATING
CLASSES AND RATE FUND
ACCOUNTS EXCEPT RIVERSOURCE INFLATION
THOSE LISTED TO THE TAX QUALIFIED PROTECTED SECURITIES
RIGHT (NONQUALIFIED) ACCOUNTS FUND CLASS W
- ----------------------------------------------------------------------------------------------

INITIAL INVESTMENT $2,000 $1,000 $5,000 $500
- ----------------------------------------------------------------------------------------------
ADDITIONAL
INVESTMENTS $100 $100 $100 None
- ----------------------------------------------------------------------------------------------
ACCOUNT BALANCE* $300 None $2,500 $500
</Table>

* If your fund account balance falls below the minimum account balance for any
reason, including a market decline, you may be asked to increase it to the
minimum account balance or establish a scheduled investment plan. If you do
not do so within 30 days, your shares may be automatically redeemed and the
proceeds mailed to you.
- --------------------------------------------------------------------------------

MINIMUM INVESTMENT AND ACCOUNT BALANCE -- SCHEDULED INVESTMENT PLANS

<Table>
<Caption>
RIVERSOURCE ABSOLUTE
RETURN CURRENCY
FOR ALL FUNDS, AND INCOME FUND
CLASSES AND RIVERSOURCE FLOATING
ACCOUNTS EXCEPT RATE FUND
THOSE LISTED TO THE TAX QUALIFIED RIVERSOURCE INFLATION
RIGHT (NONQUALIFIED) ACCOUNTS PROTECTED SECURITIES FUND CLASS W
- ----------------------------------------------------------------------------------------------

INITIAL INVESTMENT $100 $100 $5,000 $500
- ----------------------------------------------------------------------------------------------
ADDITIONAL
INVESTMENTS $100 $50 $100 None
- ----------------------------------------------------------------------------------------------
ACCOUNT BALANCE** None None $2,500 $500
</Table>

** If your fund account balance is below the minimum initial investment
described above, you must make payments at least monthly.
- --------------------------------------------------------------------------------

These minimums may be waived for accounts that are managed by an investment
professional, for accounts held in approved discretionary or non-discretionary
wrap accounts, for accounts that are part of an employer-sponsored retirement
plan, or for other account types if approved by the distributor.

The fund reserves the right to modify its minimum account requirements at any
time, with or without prior notice.

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

S.12

Please contact your financial institution for information regarding wire or
electronic funds transfer.

EXCHANGING OR SELLING SHARES

You may exchange or sell shares by having your financial institution process
your transaction. If your account is maintained directly with your financial
institution, you must contact that financial institution to exchange or sell
shares of the fund. If your account was established with the distributor, there
are a variety of methods you may use to exchange or sell shares of the fund.

WAYS TO REQUEST AN EXCHANGE OR SALE OF SHARES

ACCOUNT ESTABLISHED WITH YOUR FINANCIAL INSTITUTION

ALL REQUESTS You can exchange or sell shares by having your financial
institution process your transaction. The financial
institution through which you purchased shares may have
different policies not described in this prospectus,
including different transaction limits, exchange policies
and sale procedures.
- --------------------------------------------------------------------------------

ACCOUNT ESTABLISHED WITH THE FUND

BY MAIL Mail your exchange or sale request to:

REGULAR MAIL RIVERSOURCE INVESTMENTS (FUNDS)
P.O. BOX 8041
BOSTON, MA 02266-8041

EXPRESS MAIL RIVERSOURCE INVESTMENTS (FUNDS)
C/O BFDS
30 DAN ROAD
CANTON, MA 02021-2809

Include in your letter:

- your name

- the name of the fund(s)

- your account number

- the class of shares to be exchanged or sold

- your Social Security number or Employer Identification
number

- the dollar amount or number of shares you want to exchange
or sell

- specific instructions regarding delivery or exchange
destination

- signature(s) of registered account owner(s)
- --------------------------------------------------------------------------------

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

S.13

WAYS TO REQUEST AN EXCHANGE OR SALE OF SHARES (CONTINUED)

ACCOUNT ESTABLISHED WITH THE FUND (CONT.)

BY MAIL (CONT.)
- any special documents the transfer agent may require in
order to process your order

Corporate, trust or partnership accounts may need to send
additional documents.

Payment will be mailed to the address of record and made
payable to the names listed on the account, unless your
request specifies differently and is signed by all owners.

A Medallion Signature Guarantee is required if:

- Amount is over $50,000.

- You want your check made payable to someone other than
yourself.

- Your address has changed within the last 30 days.

- You want the check mailed to an address other than the
address of record.

- You want the proceeds sent to a bank account not on file.

- You are the beneficiary of the account and the account
owner is deceased (additional documents may be required).

A Medallion Signature Guarantee assures that a signature is
genuine and not a forgery. The financial institution
providing the Guarantee is financially liable for the
transaction if the signature is a forgery. Eligible
guarantors include commercial banks, trust companies,
savings associations, and credit unions as defined by the
Federal Deposit Insurance Act. Note: A guarantee from a
notary public is not acceptable.

NOTE: Any express mail delivery charges you pay will vary
depending on domestic or international delivery
instructions.
- --------------------------------------------------------------------------------

BY TELEPHONE Call (888) 791-3380. Unless you elect not to have telephone
exchange and sale privileges, they will automatically be
available to you. Reasonable procedures will be used to
confirm authenticity of telephone exchange or sale requests.
Telephone privileges may be modified or discontinued at any
time. Telephone exchange and sale privileges automatically
apply to all accounts except custodial, corporate or
qualified retirement accounts. You may request that these
privileges NOT apply by writing to the address above.
- --------------------------------------------------------------------------------

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

S.14

WAYS TO REQUEST AN EXCHANGE OR SALE OF SHARES (CONTINUED)

ACCOUNT ESTABLISHED WITH THE FUND (CONT.)

Payment will be mailed to the address of record and made
payable to the names listed on the account.

Telephone sale requests are limited to $100,000 per day.
- --------------------------------------------------------------------------------

BY WIRE OR ACH You can wire money from your fund account to your bank
account. Make sure we have your bank account information on
file. If we do not have this information, you will need to
send written instructions with your bank's name and a voided
check or savings account deposit slip.

Call (888) 791-3380 or send a letter of instruction, with a
Medallion Signature Guarantee if required, to the address
above.

A service fee may be charged against your account for each
wire sent.

Minimum amount: $100

Your bank or financial institution may charge additional
fees for wire transactions.
- --------------------------------------------------------------------------------

BY SCHEDULED
PAYOUT PLAN You may elect to receive regular periodic payments through
an automatic sale of shares. See the SAI for more
information.
- --------------------------------------------------------------------------------

IMPORTANT: Payments sent by a bank authorization or check that are not
guaranteed may take up to ten days to clear. This may cause your sale request to
fail to process if the requested amount includes unguaranteed funds.

EXCHANGES

Generally, you may exchange your fund shares for shares of the same class of any
other publicly offered RiverSource fund without a sales charge. For complete
information on the fund you are exchanging into, including fees and expenses,
read that fund's prospectus carefully. Your exchange will be priced at the next
NAV calculated after your transaction request is received in good order.

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

S.15

MARKET TIMING IS FREQUENT OR SHORT-TERM TRADING BY CERTAIN SHAREHOLDERS INTENDED
TO PROFIT AT THE EXPENSE OF OTHER SHAREHOLDERS BY SELLING SHARES OF A FUND
SHORTLY AFTER PURCHASE. MARKET TIMING MAY ADVERSELY IMPACT A FUND'S PERFORMANCE
BY PREVENTING THE INVESTMENT MANAGER FROM FULLY INVESTING THE ASSETS OF THE
FUND, DILUTING THE VALUE OF SHARES HELD BY LONG-TERM SHAREHOLDERS, OR INCREASING
THE FUND'S TRANSACTION COSTS.

FUNDS THAT INVEST IN SECURITIES THAT TRADE INFREQUENTLY MAY BE VULNERABLE TO
MARKET TIMERS WHO SEEK TO TAKE ADVANTAGE OF INEFFICIENCIES IN THE SECURITIES
MARKETS. FUNDS THAT INVEST IN SECURITIES THAT TRADE ON OVERSEAS SECURITIES
MARKETS MAY BE VULNERABLE TO MARKET TIMERS WHO SEEK TO TAKE ADVANTAGE OF CHANGES
IN THE VALUES OF SECURITIES BETWEEN THE CLOSE OF OVERSEAS MARKETS AND THE CLOSE
OF U.S. MARKETS, WHICH IS GENERALLY THE TIME AT WHICH A FUND'S NAV IS
CALCULATED. TO THE EXTENT THAT A FUND HAS SIGNIFICANT HOLDINGS OF HIGH YIELD
BONDS, TAX-EXEMPT SECURITIES OR FOREIGN SECURITIES, THE RISKS OF MARKET TIMING
MAY BE GREATER FOR THE FUND THAN FOR OTHER FUNDS. SEE "PRINCIPAL INVESTMENT
STRATEGIES" FOR A DISCUSSION OF THE TYPES OF SECURITIES IN WHICH YOUR FUND
INVESTS.

SEE "VALUING FUND SHARES" FOR A DISCUSSION OF THE RIVERSOURCE FUNDS' POLICY ON
FAIR VALUE PRICING, WHICH IS INTENDED, IN PART, TO REDUCE THE FREQUENCY AND
EFFECT OF MARKET TIMING.

THE RIVERSOURCE FUNDS' BOARDS HAVE ADOPTED A POLICY THAT IS DESIGNED TO DETECT
AND DETER MARKET TIMING THAT MAY BE HARMFUL TO THE FUNDS. EACH FUND SEEKS TO
ENFORCE THIS POLICY THROUGH ITS SERVICE PROVIDERS AS FOLLOWS:

- - The fund tries to distinguish market timing from trading that it believes is
not harmful, such as periodic rebalancing for purposes of asset allocation or
dollar cost averaging. Under the fund's procedures, there is no set number of
transactions in the fund that constitutes market timing. Even one purchase and
subsequent sale by related accounts may be market timing. Generally, the fund
seeks to restrict the exchange privilege of an investor who makes more than
three exchanges into or out of the fund in any 90-day period. Accounts held by
a retirement plan or a financial institution for the benefit of its
participants or clients, which typically engage in daily transactions, are not
subject to this limit, although the fund seeks the assistance of financial
institutions in applying similar restrictions on the sub-accounts of their
participants or clients.

- - If an investor's trading activity is determined to be market timing or
otherwise harmful to existing shareholders, the fund reserves the right to
modify or discontinue the investor's exchange privilege or reject the
investor's purchases or exchanges, including purchases or exchanges accepted
by a financial institution. The fund may treat accounts it believes to be
under common control as a single account for these purposes, although it may
not be able to identify all such accounts.

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

S.16

- - Although the fund does not knowingly permit market timing, it cannot guarantee
that it will be able to identify and restrict all short-term trading activity.
The fund receives purchase and sale orders through financial institutions
where market timing activity may not always be successfully detected.

Other exchange policies:

- - Exchanges must be made into the same class of shares of the new fund.

- - Exchanges into RiverSource Tax-Exempt Money Market Fund may be made only from
Class A shares.

- - If your exchange creates a new account, it must satisfy the minimum investment
amount for new purchases.

- - Once the fund receives your exchange request, you cannot cancel it.

- - Shares of the new fund may not be used on the same day for another exchange or
sale.

- - Shares of the Class W originally purchased, but no longer held in a
discretionary managed account, may not be exchanged for Class W shares of
another fund. You may continue to hold these shares in the fund. Changing your
investment to a different fund will be treated as a sale and purchase, and you
will be subject to applicable taxes on the sale and sales charges on the
purchase of the new fund.

SELLING SHARES

You may sell your shares at any time. The payment will be sent within seven days
after your request is received in good order.

When you sell shares, the amount you receive may be more or less than the amount
you invested. Your sale price will be the next NAV calculated after your request
is received in good order, minus any applicable CDSC.

REPURCHASES. You can change your mind after requesting a sale and use all or
part of the sale proceeds to purchase new shares in the same account, fund and
class from which you sold. If you reinvest in Class A, you will purchase the new
shares at NAV, up to the amount of the sale proceeds, instead of paying a sales
charge on the date of a new purchase. If you reinvest in Class B or Class C, any
CDSC you paid on the amount you are reinvesting also will be reinvested. In
order for you to take advantage of this repurchase waiver, you must notify your
financial institution within 90 days of the date your sale request was
processed. Contact your financial institution for information on required
documentation. The repurchase privilege may be modified or discontinued at any
time and use of this option may have tax consequences.

Each fund reserves the right to redeem in kind.

For more details and a description of other sales policies, please see the SAI.

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S.17

VALUING FUND SHARES

For classes of shares sold with an initial sales charge, the public offering or
purchase price is the net asset value plus the sales charge. For funds or
classes of shares sold without an initial sales charge, the public offering
price is the NAV.

Orders in good form are priced at the NAV next determined after you place your
order. Good form or good order means that your instructions have been received
in the form required by the fund. This may include, for example, providing the
fund name and account number, the amount of the transaction and all required
signatures. For more information, contact your financial institution.

The NAV is the value of a single share of a fund. The NAV is determined by
dividing the value of a fund's assets, minus any liabilities, by the number of
shares outstanding. The NAV is calculated as of the close of business on the New
York Stock Exchange (NYSE), normally 4:00 p.m. Eastern time, on each day that
the NYSE is open. Securities are valued primarily on the basis of market
quotations and floating rate loans are valued primarily on the basis of
indicative bids. Both market quotations and indicative bids are obtained from
outside pricing services approved and monitored under procedures adopted by the
Board. Certain short-term securities with maturities of 60 days or less are
valued at amortized cost.

When reliable market quotations or indicative bids are not readily available,
investments are priced at fair value based on procedures adopted by the Board.
These procedures are also used when the value of an investment held by a fund is
materially affected by events that occur after the close of a securities market
but prior to the time as of which the fund's NAV is determined. Valuing
investments at fair value involves reliance on judgment. The fair value of an
investment is likely to differ from any available quoted or published price. To
the extent that a fund has significant holdings of high yield bonds, floating
rate loans, tax-exempt securities or foreign securities that may trade
infrequently, fair valuation may be used more frequently than for other funds.
The funds use an unaffiliated service provider to assist in determining fair
values for foreign securities.

Foreign investments are valued in U.S. dollars. Some of a fund's securities may
be listed on foreign exchanges that trade on weekends or other days when the
fund does not price its shares. In that event, the NAV of the fund's shares may
change on days when shareholders will not be able to purchase or sell the fund's
shares.

DISTRIBUTIONS AND TAXES

As a shareholder you are entitled to your share of your fund's net income and
net gains. Each fund distributes dividends and capital gains to qualify as a
regulated investment company and to avoid paying corporate income and excise
taxes.

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

S.18

DIVIDENDS AND CAPITAL GAIN DISTRIBUTIONS

Your fund's net investment income is distributed to you as dividends. Dividends
may be composed of qualifying dividend income, which is eligible for
preferential tax rates under current tax law, as well as other ordinary dividend
income, which may include non-qualifying dividends, interest income and
short-term capital gains. Because of the types of income earned by fixed income
funds, it is unlikely the funds will distribute qualifying dividend income.
Capital gains are realized when a security is sold for a higher price than was
paid for it. Each realized capital gain or loss is long-term or short-term
depending on the length of time the fund held the security. Realized capital
gains and losses offset each other. The fund offsets any net realized capital
gains by any available capital loss carryovers. Net short-term capital gains are
included in net investment income. Net realized long-term capital gains, if any,
are distributed by the end of the calendar year as capital gain distributions.

REINVESTMENTS

Dividends and capital gain distributions are automatically reinvested in
additional shares in the same class of the fund unless you request distributions
in cash. The financial institution through which you purchased shares may have
different policies.

Distributions are reinvested at the next calculated NAV after the distribution
is paid. If you choose cash distributions, you will receive cash only for
distributions declared after your request has been processed.

TAXES

If you buy shares shortly before the record date of a distribution, you may pay
taxes on money earned by the fund before you were a shareholder. You will pay
the full pre-distribution price for the shares, then receive a portion of your
investment back as a distribution, which may be taxable.

For tax purposes, an exchange is considered a sale and purchase, and may result
in a gain or loss. A sale is a taxable transaction. Generally, if you sell
shares for less than their cost, the difference is a capital loss or if you sell
shares for more than their cost, the difference is a capital gain. Your gain may
be short term (for shares held for one year or less) or long term (for shares
held for more than one year).

You may not create a tax loss, based on paying a sales charge, by exchanging
shares before the 91(st) day after the day of purchase. If you buy Class A
shares and exchange into another fund before the 91(st) day after the day of
purchase, you may not include the sales charge in your calculation of tax gain
or loss on the sale of the first fund you purchased. The sales charge may be
included in the calculation of your tax gain or loss on a subsequent sale of the
second fund you purchased. For more information, see the SAI.

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

S.19

FOR TAXABLE FUNDS. Distributions of shares not held in IRAs or other retirement
accounts are subject to federal income tax and may be subject to state and local
taxes in the year they are declared. You must report distributions on your tax
returns, even if they are reinvested in additional shares.

Income received by a fund may be subject to foreign tax and withholding. Tax
conventions between certain countries and the U.S. may reduce or eliminate these
taxes.

Shares held in an IRA or qualified retirement account are generally subject to
different tax rules. Taking a distribution from your IRA or qualified retirement
plan may subject you to federal taxes, penalties and reporting requirements.
Please consult your tax advisor.

FOR RIVERSOURCE INFLATION PROTECTED SECURITIES FUND. Any increase in principal
for an inflation-protected security resulting from inflation adjustments is
considered by Internal Revenue Service regulations to be taxable income in the
year it occurs. The fund will distribute both interest income and the income
attributable to principal adjustments, both of which are taxable to
shareholders.

FOR TAX-EXEMPT FUNDS. Dividends distributed from interest earned on tax-exempt
securities (exempt-interest dividends) are exempt from federal income taxes but
may be subject to state and local taxes. Dividends distributed from capital gain
distributions and other income earned are not exempt from federal income taxes.
Distributions are taxable in the year the fund declares them regardless of
whether you take them in cash or reinvest them.

Interest on certain private activity bonds is a preference item for purposes of
the individual and corporate alternative minimum taxes. To the extent the fund
earns such income, it will flow through to its shareholders and may be taxable
to those shareholders who are subject to the alternative minimum tax. See the
SAI for more information.

Because interest on municipal bonds and notes is tax-exempt for federal income
tax purposes, any interest on money you borrow that is used directly or
indirectly to purchase fund shares is not deductible on your federal income tax
return. You should consult a tax advisor regarding its deductibility for state
and local income tax purposes.

FOR STATE TAX-EXEMPT FUNDS. The Kentucky Court of Appeals recently held that
Kentucky's tax exemption of interest on its own bonds and its taxation of
interest on the bonds of other states is illegal. The United States Supreme
Court (Supreme Court) has granted certiorari and if the Supreme Court affirms
this decision or other state courts reach the same conclusion with respect to
the states in which the State Tax-Exempt Funds invest, this decision could have
implications for the tax treatment of the bonds held by the State Tax-Exempt
Funds. For additional information regarding the Minnesota Tax-Exempt Fund,
please see "Taxes" in the SAI.

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

S.20

IMPORTANT: This information is a brief and selective summary of some of the tax
rules that apply to an investment in a fund. Because tax matters are highly
individual and complex, you should consult a qualified tax advisor.

GENERAL INFORMATION

AVAILABILITY AND TRANSFERABILITY OF FUND SHARES

Please consult your financial institution to determine availability of
RiverSource funds. Currently, RiverSource funds may be purchased or sold through
affiliated broker-dealers of RiverSource Investments and through certain
unaffiliated financial institutions. If you set up an account at a financial
institution that does not have, and is unable to obtain, a selling agreement
with the distributor of the RiverSource funds, you will not be able to transfer
RiverSource fund holdings to that account. In that event, you must either
maintain your RiverSource fund holdings with your current financial institution,
find another financial institution with a selling agreement, or sell your
shares, paying any applicable CDSC. Please be aware that transactions in taxable
accounts are taxable events and may result in income tax liability.

ADDITIONAL SERVICES AND COMPENSATION

In addition to acting as the fund's investment manager, RiverSource Investments
and its affiliates also receive compensation for providing other services to the
funds.

Administration Services. Ameriprise Financial, 200 Ameriprise Financial Center,
Minneapolis, Minnesota 55474, provides or compensates others to provide
administrative services to the RiverSource funds. These services include
administrative, accounting, treasury, and other services. Fees paid by a fund
for these services are included under "Other expenses" in the expense table
under "Fees and Expenses."

Custody Services. Ameriprise Trust Company, 200 Ameriprise Financial Center,
Minneapolis, Minnesota 55474 (the custodian or Ameriprise Trust Company),
provides custody services to all but a limited number of the RiverSource funds,
for which U.S. Bank National Association provides custody services. In addition,
Ameriprise Trust Company is paid for certain transaction fees and out-of-pocket
expenses incurred while providing services to the funds. Fees paid by a fund for
these services are included under "Other expenses" in the expense table under
"Fees and Expenses."

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

S.21

Distribution and Shareholder Services. RiverSource Distributors, Inc., 50611
Ameriprise Financial Center, Minneapolis, Minnesota 55474 (the distributor or
RiverSource Distributors), provides underwriting and distribution services to
the RiverSource funds. Under the Distribution Agreement and related distribution
and shareholder servicing plans, the distributor receives distribution and
shareholder servicing fees. The distributor may retain a portion of these fees
to support its distribution and shareholder servicing activity. The distributor
re-allows the remainder of these fees (or the full fee) to the financial
institutions that sell fund shares and provide services to shareholders. Fees
paid by a fund for these services are set forth under "Distribution (12b-1)
fees" in the expense table under "Fees and Expenses." More information on how
these fees are used is set forth under "Investment Options -- Classes of Shares"
and in the SAI. The distributor also administers any sales charges paid by an
investor at the time of purchase or at the time of sale. See "Shareholder Fees
(fees paid directly from your investment)" under "Fees and Expenses" for the
scheduled sales charge of each share class. See "Buying and Selling Shares:
Sales Charges" for variations in the scheduled sales charges, and for how these
sales charges are used by the distributor. See "Other Investment Strategies and
Risks" for the RiverSource funds' policy regarding directed brokerage.

Plan Administration Services. Under a Plan Administration Services Agreement the
fund pays for plan administration services, including services such as
implementation and conversion services, account set-up and maintenance,
reconciliation and account recordkeeping, education services and administration
to various plan types, including 529 plans, retirement plans and Health Savings
Accounts (HSAs). Fees paid by a fund for these services are included under
"Other expenses" in the expense table under "Fees and Expenses."

Transfer Agency Services. RiverSource Service Corporation, 734 Ameriprise
Financial Center, Minneapolis, Minnesota 55474 (the transfer agent or
RiverSource Service Corporation), provides or compensates others to provide
transfer agency services to the RiverSource funds. The RiverSource funds pay the
transfer agent a fee that varies by class, as set forth in the SAI, and
reimburses the transfer agent for its out-of-pocket expenses incurred while
providing these transfer agency services to the funds. Fees paid by a fund for
these services are included under "Other expenses" in the expense table under
"Fees and Expenses." RiverSource Service Corporation pays a portion of these
fees to financial institutions that provide sub-recordkeeping and other services
to fund shareholders. The SAI provides additional information about the services
provided and the fee schedules for the transfer agent agreements.

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

S.22

PAYMENTS TO FINANCIAL INSTITUTIONS

The distributor and its affiliates make or support additional cash payments out
of their own resources (including profits earned from providing services to the
fund) to financial institutions, including inter-company allocation of resources
or payments to affiliated broker-dealers, in connection with agreements between
the distributor and financial institutions pursuant to which these financial
institutions sell fund shares and provide services to their clients who are
shareholders of the fund. These payments and intercompany allocations
(collectively, "payments") do not change the price paid by investors in the fund
or fund shareholders for the purchase or ownership of fund shares of the fund,
and these payments are not reflected in the fees and expenses of the fund, as
they are not paid by the fund.

In exchange for these payments, a financial institution may elevate the
prominence or profile of the fund within the financial institution's
organization, and may provide the distributor and its affiliates with preferred
access to the financial institution's registered representatives or preferred
access to the financial institution's customers. These arrangements are
sometimes referred to as marketing and/or sales support payments, program and/or
shareholder servicing payments, or revenue sharing payments. These arrangements
create potential conflicts of interest between a financial institution's
pecuniary interest and its duties to its customers, for example, if the
financial institution receives higher payments from the sale of a certain fund
than it receives from the sale of other funds, the financial institution or its
representatives may be incented to recommend or sell shares of the fund where it
receives or anticipates receiving the higher payment instead of other investment
options that may be more appropriate for the customer. Employees of Ameriprise
Financial and its affiliates, including employees of affiliated broker-dealers,
may be separately incented to recommend or sell shares of the fund, as employee
compensation and business unit operating goals at all levels are tied to the
company's success. Certain employees, directly or indirectly, may receive higher
compensation and other benefits as investment in the fund increases. In
addition, management, sales leaders and other employees may spend more of their
time and resources promoting Ameriprise Financial and its subsidiary companies,
including RiverSource Investments, and the distributor, and the products they
offer, including the fund.

These payments are typically negotiated based on various factors including, but
not limited to, the scope and quality of the services provided by the financial
institution, its reputation in the industry, its ability to attract and retain
assets, its access to target markets, its customer relationships, the profile
the fund may obtain within the financial institution, and the access the
distributor or other representatives of the fund may have within the financial
institution for advertisement or education, including opportunities to present
at or sponsor conferences for the registered representatives of the financial
institution and its customers.

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

S.23

These payments are usually calculated based on a percentage of fund assets owned
through the financial institution and/or as a percentage of fund sales
attributable to the financial institution. Certain financial institutions
require flat fees instead of, or in addition to, these asset-based fees as
compensation for including or maintaining a fund on their platforms, and, in
certain situations, may require the reimbursement of ticket or operational
charges -- fees that a financial institution charges its registered
representatives for effecting transactions in the fund. The amount of payment
varies by financial institution (e.g., initial platform set-up fees, ongoing
maintenance or service fees, or asset or sales based fees). The amount of
payments also varies by the type of sale. For instance, purchases of one type of
fund may warrant a greater or lesser amount of payments than purchases of
another type of fund. Additionally, sale and maintenance of shares on a retail
basis may result in a greater or lesser amount of payments than for the sale and
maintenance of shares made through a plan, wrap or other fee-based program.
Payments to affiliates may include payments as compensation to employees of
RiverSource Investments who are licensed by the distributor in respect of
certain sales and solicitation activity on behalf of the fund. These payments
may be and often are significant. Additional information concerning the amount
and calculation of these payments is available in the fund's SAI.

Payments to affiliated broker-dealers are within the range of the payments the
distributor pays to similarly-situated third party financial institutions and
the payments such affiliated broker-dealers receive from third party fund
sponsors related to the sale of their sponsored funds. However, because of the
large amount of RiverSource fund assets (in aggregate) currently held in
customer accounts of the affiliated broker-dealers, the distributor and its
affiliates, in the aggregate, pay significantly more in absolute dollars than
other third-party fund sponsors pay to the affiliated broker-dealers for the
sale and servicing of their sponsored funds. This level of payment creates
potential conflicts of interest which the affiliated broker-dealers seek to
mitigate by disclosure and implementation of internal controls, as well as the
rules and regulations of applicable regulators.

From time to time, to the extent permitted by SEC and NASD rules and by other
applicable laws and regulations, the distributor and its affiliates may make
other reimbursements or payments to financial institutions or their registered
representatives, including non-cash compensation, in the form of gifts of
nominal value, occasional meals, tickets, or other entertainment, support for
due diligence trips, training and educational meetings or conference
sponsorships, support for recognition programs, and other forms of non-cash
compensation permissible under regulations to which these financial institutions
and their representatives are subject. To the extent these are made as payments
instead of reimbursement, they may provide profit to the financial institution
to the extent the cost of such services was less than the actual expense of the
service.

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

S.24

The financial institution through which you are purchasing or own shares of the
fund has been authorized directly or indirectly by the distributor to sell the
fund and/or to provide services to you as a shareholder of the fund. Investors
and current shareholders may wish to take such payment arrangements into account
when considering and evaluating any recommendations they receive relating to
fund shares. If you have questions regarding the specific details regarding the
payments your financial institution may receive from the distributor or its
affiliates related to your purchase or ownership of the fund, please contact
your financial institution. The SAI contains additional detail regarding
payments made by the distributor to financial institutions.

The payments described in this section are in addition to fees paid by the fund
to the distributor under 12b-1 plans, which fees may be used to compensate
financial institutions for the distribution of fund shares and the servicing of
fund shareholders, or paid by the fund to the transfer agent under the transfer
agent agreement or plan administration agreement, which fees may be used to
support networking or servicing fees to compensate financial institutions for
supporting shareholder account maintenance, sub-accounting, plan recordkeeping
or other services provided directly by the financial institution to shareholders
or plans and plan participants, including retirement plans, 529 plans, Health
Savings Account plans, or other plans, where participants beneficially own
shares of the fund.

Financial institutions may separately charge you additional fees. See "Buying
and Selling Shares."

ADDITIONAL MANAGEMENT INFORMATION

MANAGER OF MANAGERS EXEMPTION. The RiverSource funds have received an order from
the Securities and Exchange Commission that permits RiverSource Investments,
subject to the approval of the Board, to appoint a subadviser or change the
terms of a subadvisory agreement for a fund without first obtaining shareholder
approval. The order permits the fund to add or change unaffiliated subadvisers
or change the fees paid to subadvisers from time to time without the expense and
delays associated with obtaining shareholder approval of the change.

Before certain fixed income funds may rely on the order, holders of a majority
of the fund's outstanding voting securities will need to approve operating the
fund in this manner. There is no assurance shareholder approval will be
received, and no changes will be made without shareholder approval until that
time. For more information, see the SAI.

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

S.25

RiverSource Investments or its affiliates may have other relationships,
including significant financial relationships, with current or potential
subadvisers or their affiliates, which may create a conflict of interest. In
making recommendations to the Board to appoint or to change a subadviser, or to
change the terms of a subadvisory agreement, RiverSource Investments does not
consider any other relationship it or its affiliates may have with a subadviser,
and RiverSource Investments discloses the nature of any material relationships
it has with a subadviser to the Board.

AFFILIATED PRODUCTS. RiverSource Investments also serves as investment manager
to RiverSource funds that provide asset-allocation services to shareholders by
investing in shares of other RiverSource funds (Funds of Funds) and to
discretionary managed accounts (collectively referred to as "affiliated
products"). A fund may experience relatively large purchases or redemptions from
the affiliated products. Although RiverSource Investments seeks to minimize the
impact of these transactions by structuring them over a reasonable period of
time or through other measures, a fund may experience increased expenses as it
buys and sells securities to manage transactions for the affiliated products. In
addition, because the affiliated products may own a substantial portion of a
fund, a redemption by one or more affiliated product could cause a fund's
expense ratio to increase as the fund's fixed costs would be spread over a
smaller asset base. RiverSource Investments monitors expense levels and is
committed to offering funds that are competitively priced. RiverSource
Investments will report to the Board on the steps it has taken to manage any
potential conflicts.

CASH RESERVES. A fund may invest its daily cash balance in RiverSource Short-
Term Cash Fund (Short-Term Cash Fund), a money market fund established for the
exclusive use of the RiverSource funds and other institutional clients of
RiverSource Investments. While Short-Term Cash Fund does not pay an advisory fee
to RiverSource Investments, it does incur other expenses, and is expected to
operate at a very low expense ratio. A fund will invest in Short-Term Cash Fund
only to the extent it is consistent with the fund's investment objectives and
policies. Short-Term Cash Fund is not insured or guaranteed by the FDIC or any
other government agency.

FUND HOLDINGS DISCLOSURE. The Board has adopted policies and procedures that
govern the timing and circumstances of disclosure to shareholders and third
parties of information regarding the securities owned by a fund. A description
of these policies and procedures is included in the SAI.

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

S.26

LEGAL PROCEEDINGS. Ameriprise Financial and certain of its affiliates have
historically been involved in a number of legal, arbitration and regulatory
proceedings, including routine litigation, class actions, and governmental
actions, concerning matters arising in connection with the conduct of their
business activities. Ameriprise Financial believes that the fund is not
currently the subject of, and that neither Ameriprise Financial nor any of its
affiliates are the subject of, any pending legal, arbitration or regulatory
proceedings that are likely to have a material adverse effect on the fund or the
ability of Ameriprise Financial or its affiliates to perform under their
contracts with the fund. Information regarding certain pending and settled legal
proceedings may be found in the Fund's shareholder reports and in the SAI.
Additionally, Ameriprise Financial is required to make 10-Q, 10-K and, as
necessary, 8-K filings with the Securities and Exchange Commission on legal and
regulatory matters that relate to Ameriprise Financial and its affiliates.
Copies of these filings may be obtained by accessing the SEC website at
www.sec.gov.

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

S.27

THIS PAGE LEFT BLANK INTENTIONALLY

This fund can be purchased from Ameriprise Financial Services or from a limited
number of other authorized financial institutions. The fund can be found under
the "RiverSource" banner in most mutual fund quotations.

Additional information about the fund and its investments is available in the
fund's SAI, and annual and semiannual reports to shareholders. In the fund's
annual report, you will find a discussion of market conditions and investment
strategies that significantly affected the fund's performance during its most
recent fiscal year. The SAI is incorporated by reference in this prospectus. For
a free copy of the SAI, the annual report, or the semiannual report, or to
request other information about the fund, contact RiverSource Funds or your
financial institution. To make a shareholder inquiry, contact the financial
institution through whom you purchased the fund.

RiverSource Funds
734 Ameriprise Financial Center
Minneapolis, MN 55474
(888) 791-3380

RiverSource Funds information available at RiverSource Investments website
address:
riversource.com/funds

You may review and copy information about the fund, including the SAI, at the
Securities and Exchange Commission's (Commission) Public Reference Room in
Washington, D.C. (for information about the public reference room call
1-202-551-8090). Reports and other information about the fund are available on
the EDGAR Database on the Commission's Internet site at www.sec.gov. Copies of
this information may be obtained, after paying a duplicating fee, by electronic
request at the following E-mail address: publicinfo@sec.gov, or by writing to
the Public Reference Section of the Commission, 100 F Street, N.E., Washington,
D.C. 20549-0102.

Investment Company Act File #811-2503

<Table>

TICKER SYMBOL
Class A: INBNX Class B: ININX Class C: AXBCX Class I: RDBIX
Class R2: -- Class R3: RSDBX Class R4: IDBYX Class R5: RSVBX Class W: RVBWX
</Table>

(RIVERSOURCE INVESTMENTS LOGO) S-6495-99 AA (10/07)