FUND SUMMARY Janus Conservative Allocation Fund

Janus Conservative Allocation Fund seeks total return through a primary emphasis on income with a secondary emphasis on growth of capital.

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This table describes the fees and expenses that you may pay if you buy and hold Shares of the Fund. Each share class has different expenses, but represents an investment in the same Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

EXAMPLE:

The Example assumes that you invest $10,000 in the Fund for the time periods indicated and reinvest all dividends and distributions. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses (including the operating expenses of the underlying funds) without waivers remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example Janus Conservative Allocation Fund Class A, C, S, I, T Shares (USD $)	Expense Example, By Year, Column [Text]	1 Year	3 Years	5 Years	10 Years
Class A	Class A Shares	668	866	1,080	1,696
Class C	Class C Shares	276	545	939	2,041
Class S	Class S Shares	123	384	665	1,466
Class I	Class I Shares	79	246	428	954
Class T	Class T Shares	97	303	525	1,166

Expense Example, No Redemption Janus Conservative Allocation Fund Class A, C, S, I, T Shares (USD $)	Expense Example, No Redemption, By Year, Column [Text]	1 Year	3 Years	5 Years	10 Years
Class A	Class A Shares	668	866	1,080	1,696
Class C	Class C Shares	176	545	939	2,041
Class S	Class S Shares	123	384	665	1,466
Class I	Class I Shares	79	246	428	954
Class T	Class T Shares	97	303	525	1,166

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 12% of the average value of its portfolio.

The Fund seeks to achieve its investment objective by investing in other Janus mutual funds (“underlying funds”) that represent a variety of asset classes and investment styles. The Fund pursues this objective by investing in a diversified portfolio of underlying funds resulting in an allocation of the Fund’s investments that normally provides exposure of approximately 40% to stocks and 60% to bonds and money market securities. The target allocation and the allocation of the Fund’s assets among underlying funds are based on quantitative and qualitative analysis. Because it invests in other funds, the Fund is considered a “fund of funds.”

The Fund’s asset allocation is intended to diversify investments among stocks, bonds, and cash equivalents. The portfolio manager regularly reviews the allocation of Fund assets in the underlying funds and may modify the underlying funds’ weightings or substitute other underlying funds to emphasize and mitigate risk exposures that may arise as a result of the implementation of the allocations. An independent asset allocation service provides evaluations of asset allocations that the portfolio manager may use in implementing the allocations among the underlying funds. The portfolio manager continually monitors asset class allocations and periodically rebalances the Fund’s investments in the underlying funds. The portfolio manager may change the Fund’s asset class allocations, the underlying funds, an underlying fund’s asset category, or weightings among asset classes or underlying funds without prior shareholder notice.

The Fund will normally allocate approximately 60% of its investments to underlying bond funds and money market instruments; and approximately 40% of its investments to underlying funds that provide varying exposure to large U.S.-based companies, small- to mid-capitalization companies, and international companies (including those with exposure to emerging markets). Refer to Appendix A in this Prospectus for a brief description of the investment strategies of each of the currently available underlying funds.

When market conditions dictate a more defensive strategy, the Fund or an underlying fund may temporarily hold cash or invest its assets in temporary investments. In that case, the Fund may take positions that are inconsistent with its investment objective. As a result, the Fund may not achieve its investment objective.

The biggest risk is that the Fund’s returns will vary, and you could lose money. The Fund is designed for long-term investors seeking income and, to a lesser extent, growth of capital. Investments in a portfolio with common stock exposure tend to be more volatile than many other investment choices.

Main Risks Associated with the Fund

Allocation Risk. The Fund’s ability to achieve its investment objective depends largely upon Janus Capital’s allocation of assets among the underlying funds and other securities, using the optimization process and the judgment of the portfolio manager. You could lose money on your investment in the Fund as a result of these allocations. The Fund will typically invest in a number of different underlying funds; however, to the extent that the Fund invests a significant portion of its assets in a single underlying fund, it will be more sensitive to the risks associated with that fund and any investments in which that fund concentrates.

Affiliated Fund Risk. Janus Capital has the authority to select and substitute underlying affiliated mutual funds. The fees paid to Janus Capital by some Janus funds are generally higher than the fees paid to Janus Capital by the Fund or by other funds and share classes available for investment by the Fund. These conditions may create a conflict of interest when selecting underlying affiliated mutual funds and share classes for investment. Janus Capital, however, is a fiduciary to the Fund and its shareholders and is legally obligated to act in their best interest when selecting underlying affiliated mutual funds.

Main Risks Associated with the Underlying Funds and Securities

The biggest risk is that the underlying funds’ returns will vary, and you could lose money.

Fixed-Income Securities Risk. Approximately 60% of the Fund’s assets are allocated to fixed-income securities through investments in underlying funds. Typically, the values of fixed-income securities change inversely with prevailing interest rates. Therefore, a fundamental risk of fixed-income securities is interest rate risk, which is the risk that their value will generally decline as prevailing interest rates rise, which may cause an underlying fund’s net asset value to likewise decrease. How specific fixed-income securities may react to changes in interest rates will depend on the specific characteristics of each security. Fixed-income securities are also subject to credit risk, prepayment risk, valuation risk, and liquidity risk.

Mortgage-Backed Securities Risk. Mortgage-backed securities tend to be more sensitive to changes in interest rates than other types of securities. Investments in mortgage-backed securities are subject to both extension risk, where borrowers extend the duration of their mortgages in times of rising interest rates, and prepayment risk, where borrowers pay off their mortgages sooner than expected in times of declining interest rates. These risks may reduce the Fund’s returns. In addition, investments in mortgage-backed securities, including those comprised of subprime mortgages, may be subject to a higher degree of credit risk, valuation risk, and liquidity risk than various other types of fixed-income securities.

Market Risk. Approximately 40% of the Fund’s assets are allocated to equity investments through investments in underlying funds. The value of an underlying fund’s portfolio may decrease if the value of an individual company or security, or multiple companies or securities, in the portfolio decreases or if a portfolio manager’s belief about a company’s intrinsic worth is incorrect. Further, regardless of how well individual companies or securities perform, the value of an underlying fund’s portfolio could also decrease if there are deteriorating economic or market conditions. It is important to understand that the value of your investment may fall, sometimes sharply, in response to changes in the market, and you could lose money.

Foreign Exposure Risk. Certain underlying funds may have significant exposure to foreign markets, including emerging markets, which can be more volatile than the U.S. markets. As a result, an underlying fund’s returns and net asset value may be affected to a large degree by fluctuations in currency exchange rates or political or economic conditions in a particular country. A market swing in one or more countries or regions where an underlying fund has invested a significant amount of its assets may have a greater effect on an underlying fund’s performance than it would in a more geographically diversified portfolio. An underlying fund’s investments in emerging market countries may involve risks greater than, or in addition to, the risks of investing in more developed countries.

Emerging Markets Risk. The risks of foreign investing mentioned above are heightened when investing in emerging markets. Emerging markets securities are exposed to a number of additional risks, which may result from less government supervision and regulation of business and industry practices (including the potential lack of strict finance and accounting controls and standards), stock exchanges, brokers, and listed companies, making these investments potentially more volatile in price and less liquid than investments in developed securities markets, resulting in greater risk to investors. In addition, an underlying fund’s investments may be denominated in foreign currencies and therefore, changes in the value of a country’s currency compared to the U.S. dollar may affect the value of an underlying fund’s investments. To the extent that an underlying fund invests a significant portion of its assets in the securities of issuers in or companies of a single country or region, it is more likely to be impacted by events or conditions affecting that country or region which could have a negative impact on the Fund’s performance. Some of the risks of investing directly in foreign and emerging market securities may be reduced when an underlying fund invests indirectly in foreign securities through various other investment vehicles including derivatives, which also involve specialized risks.

Exchange-Traded Funds Risk. Certain underlying funds may purchase shares of exchange-traded funds (“ETFs”) to gain exposure to a particular portion of the market. ETFs are pooled investment vehicles, which may be managed or unmanaged, that generally seek to track the performance of a specific index. ETFs are traded on an exchange at market prices that may vary from the net asset value of their underlying investments. When an underlying fund invests in an ETF, in addition to directly bearing the expenses associated with its own operations, it will bear a pro rata portion of the ETF’s expenses. ETFs have certain inherent risks generally associated with investments in a portfolio of common stocks, including the risk that the general level of stock prices may decline, thereby adversely affecting the value of each unit of the ETF. ETFs also involve the risk that an active trading market for an ETF’s shares may not develop or be maintained.

Exchange-Traded Notes Risk. Certain underlying funds may invest in exchange-traded notes (“ETNs”), which are debt securities whose returns are linked to a particular index. ETNs are typically linked to the performance of a commodities index that reflects the potential return on unleveraged investments in futures contracts of physical commodities, plus a specified rate of interest that could be earned on cash collateral. ETNs are subject to credit risk. The value of an ETN may vary and may be influenced by time to maturity, level of supply and demand for the ETN, volatility and lack of liquidity in underlying commodities markets, changes in the applicable interest rates, changes in the issuer’s credit rating, and economic, legal, political, or geographic events that affect the referenced commodity. When an underlying fund invests in ETNs it will bear its proportionate share of any fees and expenses borne by the ETN. There may be restrictions on an underlying fund’s right to redeem its investment in an ETN, which is meant to be held until maturity. An underlying fund’s decision to sell its ETN holdings may be limited by the availability of a secondary market.

Derivatives Risk. Certain underlying funds may invest in derivatives. Derivatives can be highly volatile and involve risks in addition to the risks of the underlying referenced securities. Gains or losses from a derivative can be substantially greater than the derivative’s original cost, and can therefore involve leverage. Derivatives can be less liquid than other types of investments and entail the risk that the counterparty will default on its payment obligations.

Securities Lending Risk. Certain underlying funds may seek to earn additional income through lending their securities to certain qualified broker-dealers and institutions. There is the risk that when portfolio securities are lent, the securities may not be returned on a timely basis, and the underlying fund may experience delays and costs in recovering the security or gaining access to the collateral provided to collateralize the loan. If the underlying fund is unable to recover a security on loan, the underlying fund may use the collateral to purchase replacement securities in the market. There is a risk that the value of the collateral could decrease below the cost of the replacement security by the time the replacement investment is made, resulting in a loss to the underlying fund.

An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

The following information provides some indication of the risks of investing in the Fund by showing how the Fund’s performance has varied over time. Class T Shares (formerly named Class J Shares, the initial share class) of the Fund commenced operations with the Fund’s inception. Class A Shares, Class C Shares, Class S Shares, and Class I Shares of the Fund commenced operations on July 6, 2009.

• The performance shown for Class T Shares is calculated using the fees and expenses of Class T Shares in effect during the periods shown, net of any applicable fee and expense limitations or waivers.

• The performance shown for Class A Shares, Class C Shares, Class S Shares, and Class I Shares for periods prior to July 6, 2009, reflects the performance of the Fund’s former Class J Shares, calculated using the fees and expenses of each respective share class, without the effect of any fee and expense limitations or waivers.

If Class A Shares, Class C Shares, Class S Shares, and Class I Shares of the Fund had been available during periods prior to July 6, 2009, the performance shown for each respective share class may have been different. The performance shown for periods following the Fund’s commencement of Class A Shares, Class C Shares, Class S Shares, and Class I Shares reflects the fees and expenses of each respective share class, net of any applicable fee and expense limitations or waivers.

The bar chart depicts the change in performance from year to year during the periods indicated. Performance information for each underlying fund is available in its prospectus and/or the most recent annual or semiannual report. The bar chart figures do not include any applicable sales charges that an investor may pay when they buy or sell Class A Shares or Class C Shares of the Fund. If sales charges were included, the returns would be lower. The table compares the Fund’s average annual returns for the periods indicated to broad-based securities market indices. The indices are not actively managed and are not available for direct investment. All figures assume reinvestment of dividends and distributions. For certain periods, the Fund’s performance reflects the effect of expense waivers. Without the effect of these expense waivers, the performance shown would have been lower.

The Fund’s past performance (before and after taxes) does not necessarily indicate how it will perform in the future. Updated performance information is available at janus.com/advisor/mutual-funds or by calling 1-877-335-2687.

The Fund’s year-to-date return as of the calendar quarter ended September 30, 2011 was -2.59%.

Average Annual Total Returns Janus Conservative Allocation Fund Class A, C, S, I, T Shares	Column	Label		Index No Deduction for Fees, Expenses, Taxes [Text]	1 Year	5 Years	Since Inception	Inception Date
Return Before Taxes Class T	Class T Shares	Return Before Taxes			10.60%	7.00%	7.00%	Dec. 30, 2005
Return Before Taxes Class A	Class A Shares	Return Before Taxes	^[1]		4.19%	5.53%	5.52%	Dec. 30, 2005
Return Before Taxes Class C	Class C Shares	Return Before Taxes	^[2]		8.58%	6.00%	6.00%	Dec. 30, 2005
Return Before Taxes Class S	Class S Shares	Return Before Taxes			10.35%	6.51%	6.51%	Dec. 30, 2005
Return Before Taxes Class I	Class I Shares	Return Before Taxes			10.79%	7.00%	7.00%	Dec. 30, 2005
Return After Taxes on Distributions Class T	Class T Shares	Return After Taxes on Distributions			9.36%	5.94%	5.94%	Dec. 30, 2005
Return After Taxes on Distributions and Sale of Fund Shares Class T	Class T Shares	Return After Taxes on Distributions and Sale of Fund Shares	^[3]		6.96%	5.44%	5.44%	Dec. 30, 2005
S&P 500® Index		S&P 500^® Index		(reflects no deduction for expenses, fees, or taxes)	15.06%	2.29%	2.29%	Dec. 30, 2005
Conservative Allocation Index		Conservative Allocation Index		(reflects no deduction for expenses, fees, or taxes)	10.38%	5.15%	5.14%	Dec. 30, 2005

[1]	Calculated assuming maximum permitted sales loads.
[2]	The one year return is calculated to include the contingent deferred sales charge.
[3]	If the Fund incurs a loss, which generates a tax benefit, the Return After Taxes on Distributions and Sale of Fund Shares may exceed the Fund's other return figures.

INVESTMENT OBJECTIVE

FEES AND EXPENSES OF THE FUND

For Class A Shares, you may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the Fund or in other Janus mutual funds. More information about these and other discounts, as well as eligibility requirements for each share class, is available from your financial professional and in the “Purchases” section on page 44 of the Fund’s Prospectus and in the “Purchases” section on page 64 of the Fund’s Statement of Additional Information.

Shareholder Fees Janus Moderate Allocation Fund Class A, C, S, I, T Shares	Class A	Class C	Class S	Class I	Class T
Shareholder Fees Column [Text]	Class A	Class C	Class S	Class I	Class T
Maximum Sales Charge (load) Imposed on Purchases (as a percentage of offering price)	5.75%	none	none	none	none
Maximum Deferred Sales Charge (load) (as a percentage of the lower of original purchase price or redemption proceeds)	none	1.00%	none	none	none

Annual Fund Operating Expenses Janus Moderate Allocation Fund Class A, C, S, I, T Shares		Class A	Class C	Class S	Class I	Class T
Operating Expenses Column [Text]		Class A	Class C	Class S	Class I	Class T
Management Fees		0.05%	0.05%	0.05%	0.05%	0.05%
Distribution/Service (12b-1) Fees		0.25%	1.00%	0.25%	none	none
Other Expenses		0.20%	0.11%	0.34%	0.12%	0.30%
Acquired Fund Fees and Expenses		0.63%	0.63%	0.63%	0.63%	0.63%
Total Annual Fund Operating Expenses	^[1]	1.13%	1.79%	1.27%	0.80%	0.98%

[1]

Janus Capital has contractually agreed to waive the Fund's total annual fund operating expenses (excluding any expenses of an underlying fund (acquired fund fees and expenses), the distribution and shareholder servicing fees - applicable to Class A Shares, Class C Shares, and Class S Shares; administrative services fees payable pursuant to the Transfer Agency Agreement - applicable to Class S Shares and Class T Shares; brokerage commissions; interest; dividends; taxes; and extraordinary expenses) to 0.39% until at least November 1, 2012. The contractual waiver may be terminated or modified prior to this date only at the discretion of the Board of Trustees.

The following Example is based on expenses without waivers. The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.

If Shares are redeemed:

If Shares are not redeemed:

Portfolio Turnover:

PRINCIPAL INVESTMENT STRATEGIES

PRINCIPAL INVESTMENT RISKS

PERFORMANCE INFORMATION

Annual Total Returns for Class T Shares (calendar year-end)

Best Quarter: Second Quarter 2009 14.27% Worst Quarter: Fourth Quarter 2008 -11.62%

Average Annual Total Returns (periods ended 12/31/10)

The Moderate Allocation Index is an internally-calculated, hypothetical combination of unmanaged indices that combines total returns from the Dow Jones Wilshire 5000 Index (40%), the Barclays Capital U.S. Aggregate Bond Index (40%), the MSCI EAFE^® Index (18%), and the Morgan Stanley Capital International Emerging Markets Free Index^SM (2%).

After-tax returns are calculated using distributions for the Fund’s Class T Shares (formerly named Class J Shares, the initial share class). After-tax returns are calculated using the historically highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on your individual tax situation and may differ from those shown in the preceding table. The after-tax return information shown above does not apply to Fund shares held through a tax-deferred account, such as a 401(k) plan or an IRA.

After-tax returns are only shown for Class T Shares of the Fund. After-tax returns for the other classes of Shares will vary from those shown for Class T Shares due to varying sales charges (as applicable), fees, and expenses among the classes.

FUND SUMMARY Janus Growth Allocation Fund

Janus Growth Allocation Fund seeks total return through a primary emphasis on growth of capital with a secondary emphasis on income.

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This table describes the fees and expenses that you may pay if you buy and hold Shares of the Fund. Each share class has different expenses, but represents an investment in the same Fund.

SHAREHOLDER FEES (fees paid directly from your investment)

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

EXAMPLE:

The Example assumes that you invest $10,000 in the Fund for the time periods indicated and reinvest all dividends and distributions. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses (including the operating expenses of the underlying funds) without waivers remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example Janus Growth Allocation Fund Class A, C, S, I, T Shares (USD $)	Expense Example, By Year, Column [Text]	1 Year	3 Years	5 Years	10 Years
Class A	Class A Shares	683	911	1,156	1,860
Class C	Class C Shares	292	594	1,021	2,212
Class S	Class S Shares	137	428	739	1,624
Class I	Class I Shares	95	296	515	1,143
Class T	Class T Shares	105	328	569	1,259

Expense Example, No Redemption Janus Growth Allocation Fund Class A, C, S, I, T Shares (USD $)	Expense Example, No Redemption, By Year, Column [Text]	1 Year	3 Years	5 Years	10 Years
Class A	Class A Shares	683	911	1,156	1,860
Class C	Class C Shares	192	594	1,021	2,212
Class S	Class S Shares	137	428	739	1,624
Class I	Class I Shares	95	296	515	1,143
Class T	Class T Shares	105	328	569	1,259

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal period, the Fund’s portfolio turnover rate was 26% of the average value of its portfolio.

The Fund seeks to achieve its investment objective by investing in other Janus mutual funds (“underlying funds”) that represent a variety of asset classes and investment styles. The Fund pursues this objective by investing in a diversified portfolio of underlying funds resulting in an allocation of the Fund’s investments that normally provides exposure of approximately 80% to stocks and 20% to bonds and money market securities. The target allocation and the allocation of the Fund’s assets among underlying funds are based on quantitative and qualitative analysis. Because it invests in other funds, the Fund is considered a “fund of funds.”

The Fund’s asset allocation is intended to diversify investments among stocks, bonds, and cash equivalents. The portfolio manager regularly reviews the allocation of Fund assets in the underlying funds and may modify the underlying funds’ weightings or substitute other underlying funds to emphasize and mitigate risk exposures that may arise as a result of the implementation of the allocations. An independent asset allocation service provides evaluations of asset allocations that the portfolio manager may use in implementing the allocations among the underlying funds. The portfolio manager continually monitors asset class allocations and periodically rebalances the Fund’s investments in the underlying funds. The portfolio manager may change the Fund’s asset class allocations, the underlying funds, an underlying fund’s asset category, or weightings among asset classes or underlying funds without prior shareholder notice.

The Fund will normally allocate approximately 80% of its investments to underlying funds that provide varying exposure to large U.S.-based companies, small- to mid-capitalization companies, and international companies (including those with exposure to emerging markets); and approximately 20% of its investments to underlying bond funds and money market instruments. Refer to Appendix A in this Prospectus for a brief description of the investment strategies of each of the currently available underlying funds.

When market conditions dictate a more defensive strategy, the Fund or an underlying fund may temporarily hold cash or invest its assets in temporary investments. In that case, the Fund may take positions that are inconsistent with its investment objective. As a result, the Fund may not achieve its investment objective.

The biggest risk is that the Fund’s returns will vary, and you could lose money. The Fund is designed for long-term investors seeking growth of capital and, to a lesser extent, income. Investments in a portfolio with common stock exposure tend to be more volatile than many other investment choices.

Main Risks Associated with the Fund

Allocation Risk. The Fund’s ability to achieve its investment objective depends largely upon Janus Capital’s allocation of assets among the underlying funds and other securities, using the optimization process and the judgment of the portfolio manager. You could lose money on your investment in the Fund as a result of these allocations. The Fund will typically invest in a number of different underlying funds; however, to the extent that the Fund invests a significant portion of its assets in a single underlying fund, it will be more sensitive to the risks associated with that fund and any investments in which that fund concentrates.

Affiliated Fund Risk. Janus Capital has the authority to select and substitute underlying affiliated mutual funds. The fees paid to Janus Capital by some Janus funds are generally higher than the fees paid to Janus Capital by the Fund or by other funds and share classes available for investment by the Fund. These conditions may create a conflict of interest when selecting underlying affiliated mutual funds and share classes for investment. Janus Capital, however, is a fiduciary to the Fund and its shareholders and is legally obligated to act in their best interest when selecting underlying affiliated mutual funds.

Main Risks Associated with the Underlying Funds and Securities

The biggest risk is that the underlying funds’ returns will vary, and you could lose money.

Market Risk. Approximately 80% of the Fund’s assets are allocated to equity investments through investments in underlying funds. The value of an underlying fund’s portfolio may decrease if the value of an individual company or security, or multiple companies or securities, in the portfolio decreases or if a portfolio manager’s belief about a company’s intrinsic worth is incorrect. Further, regardless of how well individual companies or securities perform, the value of an underlying fund’s portfolio could also decrease if there are deteriorating economic or market conditions. It is important to understand that the value of your investment may fall, sometimes sharply, in response to changes in the market, and you could lose money.

Fixed-Income Securities Risk. Approximately 20% of the Fund’s assets are allocated to fixed-income securities through investments in underlying funds. Typically, the values of fixed-income securities change inversely with prevailing interest rates. Therefore, a fundamental risk of fixed-income securities is interest rate risk, which is the risk that their value will generally decline as prevailing interest rates rise, which may cause an underlying fund’s net asset value to likewise decrease. How specific fixed-income securities may react to changes in interest rates will depend on the specific characteristics of each security. Fixed-income securities are also subject to credit risk, prepayment risk, valuation risk, and liquidity risk.