Janus World Allocation Fund | Class A, C, S, I, T Shares

FUND SUMMARY Janus World Allocation Fund

INVESTMENT OBJECTIVE

Janus World Allocation Fund seeks long-term growth of capital with a secondary emphasis on income.

FEES AND EXPENSES OF THE FUND

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.

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 32 of the Fund’s Prospectus and in the “Purchases” section on page 64 of the Fund’s Statement of Additional Information.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees Janus World 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 (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses Janus World 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		0.07%	0.07%	0.07%	0.07%	0.07%
Distribution/Service (12b-1) Fees		0.25%	1.00%	0.25%	none	none
Other Expenses		1.24%	1.36%	1.47%	1.34%	1.32%
Acquired Fund Fees and Expenses		0.66%	0.66%	0.66%	0.66%	0.66%
Total Annual Fund Operating Expenses	[1]	2.22%	3.09%	2.45%	2.07%	2.05%
Fee Waiver	[1]	0.83%	0.95%	0.81%	0.93%	0.66%
Net Annual Fund Operating Expenses After Fee Waiver	[1]	1.39%	2.14%	1.64%	1.14%	1.39%

EXAMPLE:

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.

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:

If Shares are redeemed:

Expense Example Janus World 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	787	1,229	1,696	2,982
Class C	Class C Shares	412	954	1,620	3,402
Class S	Class S Shares	248	764	1,306	2,786
Class I	Class I Shares	210	649	1,114	2,400
Class T	Class T Shares	208	643	1,103	2,379

If Shares are not redeemed:

Expense Example, No Redemption Janus World 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	787	1,229	1,696	2,982
Class C	Class C Shares	312	954	1,620	3,402
Class S	Class S Shares	248	764	1,306	2,786
Class I	Class I Shares	210	649	1,114	2,400
Class T	Class T Shares	208	643	1,103	2,379

Portfolio Turnover:

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 71% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

The Fund pursues its investment objective by investing in a diversified portfolio of other Janus mutual funds (“underlying funds”) and securities that provide exposure to issuers located throughout the world. Through its investment in the underlying funds, the Fund invests in issuers from several different countries, including the United States, and may, under unusual circumstances, be invested in a single country. The Fund may also have significant exposure to emerging markets. Because it invests in other funds, the Fund is considered a “fund of funds.” The Fund utilizes Janus Capital’s proprietary process to allocate assets across the following three asset categories (as defined by Janus Capital):

• Core – The Core category seeks to provide market-like exposure by investing in funds that in turn primarily invest in a broad range of traditional asset classes such as large-, mid-, and small-cap stocks, U.S. and non-U.S. stocks, growth and value stocks, and investment-grade bonds. While not a primary strategy, the underlying funds may also invest in emerging market stocks and high-yield bonds. A primary goal of the underlying funds in the Core category is to provide shareholders with access to a broad range of investable assets in proportion to each asset class’ representation in today’s global, integrated market as determined by Janus Capital.

• Alpha – The Alpha category seeks to generate higher-than-market returns on a risk-adjusted basis by investing in funds that in turn invest in a broad range of traditional asset classes such as large-, mid-, and small-cap stocks, U.S. and non-U.S. stocks, growth and value stocks, emerging market stocks, investment-grade bonds, and high-yield bonds. Unlike funds in the Core category, the Alpha category is less focused on the asset class composition of the global market. Instead, the Alpha category is comprised of funds, unconstrained by asset class or investment style, that Janus Capital believes may generate higher-than-market returns over a market cycle.

• Alternative – The Alternative category is comprised of non-traditional investments with historically low correlation to the assets in the Core and Alpha categories, such as certain exchange-traded funds (“ETFs”), exchange-traded notes (“ETNs”), investments with hedge fund strategy exposure, commodities-related securities, real estate-related securities, and structured products.

The Fund attempts to maximize returns by investing the Fund’s assets in underlying funds investing in stocks (U.S. and non-U.S.), bonds, cash equivalents, alternative asset classes (such as real estate-related securities and commodity-related securities), and alternative investment strategies (such as leveraged and sector-based strategies). The target allocation of the Fund’s assets among underlying funds is based on an optimization process that utilizes quantitative analysis of a number of factors, such as historical risk, performance, fund classifications, and the relationship among underlying funds, as well as the portfolio manager’s judgment. Janus Capital analyzes Fund allocations on a regular basis in order to integrate current market data and reallocates on a quarterly basis.

The Fund’s portfolio manager determines the overall composition of the Fund, oversees the investment process, and is responsible for the day-to-day management of the Fund. The portfolio manager consults with a committee comprised of Janus Capital investment professionals (“Asset Allocation Committee”) to regularly review the process and the allocation of the Fund’s assets among the underlying funds to determine modifications to the underlying funds’ asset categories and/or weightings, or to substitute other underlying funds to emphasize and mitigate risk exposures that may arise as a result of the implementation of the allocations. The portfolio manager and Asset Allocation Committee normally review asset allocations on a quarterly basis. The portfolio manager oversees the implementation of trades on behalf of the Fund.

The Fund’s investments will be rebalanced to the identified optimal weightings on a quarterly basis, although more frequent changes can occur. The Fund’s asset class or category, category allocations, underlying funds, or underlying fund weightings may change without prior shareholder notice.

The Fund will normally allocate approximately 90% of its assets to Janus-managed mutual funds and approximately 10% to unaffiliated pooled investment vehicles (e.g., ETFs) and derivatives. For information on the potential underlying Janus funds currently available for investment by the Fund, including investment objectives and strategies, see “Investment Objectives and Strategies of the Underlying Funds” in Appendix A.

The Fund may invest in ETFs and ETNs to complement its investment in the underlying funds if there are asset classes not covered by the underlying funds or to better manage cash positions.

The Fund may invest its assets in derivatives, which are instruments that have a value derived from an underlying asset, such as equity securities, bonds, commodities, currencies, interest rates, or market indices, as substitutes for securities in which the Fund invests. The Fund may invest in derivative instruments (by taking long and/or short positions) including, but not limited to, swap agreements to earn income and enhance uncorrelated returns, to increase or decrease exposure to a particular market, to manage or adjust the risk profile of the Fund, or as alternatives to direct investments. For more information on the Fund’s use of derivatives, refer to the Fund’s shareholder reports and Form N-Q reports, which are filed with the Securities and Exchange Commission.

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.

PRINCIPAL INVESTMENT RISKS

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 and alternative investment 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.

Derivatives Risk. The Fund and 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.

Commodity-Linked Derivative Investment Risk. The Fund may invest in derivatives that have exposure to the commodities markets. This exposure may subject the Fund to greater volatility than investments in traditional securities. The value of a commodity-linked derivative investment typically is based upon the price movements of a physical commodity (such as heating oil, livestock, or agricultural products), a commodity futures contract or commodity index, or some other readily measurable economic variable. The value of commodity-linked derivative instruments may therefore be affected by changes in overall market movements, volatility of the underlying benchmark, changes in interest rates, or other factors affecting a particular industry or commodity such as drought, floods, weather, livestock disease, embargoes, tariffs, and international economic, political, and regulatory developments.

Exchange-Traded Funds Risk. The Fund may purchase shares of 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 the 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. The Fund may invest in 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 the Fund invests in ETNs it will bear its proportionate share of any fees and expenses borne by the ETN. There may be restrictions on the Fund’s right to redeem its investment in an ETN, which is meant to be held until maturity. The Fund’s decision to sell its ETN holdings may be limited by the availability of a secondary market.

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. Underlying funds investing in equity securities are subject to the risks associated with investments in common stocks, which tend to be more volatile than many other investment choices. 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. Through the Fund’s investments in underlying funds holding fixed-income securities, the Fund is subject to the risks associated with investments in a variety of fixed-income securities, which may be less volatile than underlying funds that invest most of their assets in common stocks; returns and yields will vary, and you could lose money. 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.

Foreign Exposure Risk. The Fund and 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, the Fund’s and 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 the Fund or an underlying fund has invested a significant amount of its assets may have a greater effect on the Fund’s or an underlying Fund’s performance than it would in a more geographically diversified portfolio. The Fund’s or 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, the Fund’s or 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 the Fund’s or an underlying fund’s investments. To the extent that the Fund or 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 the Fund or an underlying fund invests indirectly in foreign securities through various other investment vehicles including derivatives, which also involve specialized risks.

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.

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.

PERFORMANCE INFORMATION

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 I Shares, Class A Shares, Class C Shares, and Class S Shares of the Fund commenced operations on July 6, 2009, after the reorganization of each corresponding class of shares of Janus Adviser Modular Portfolio Construction^® Fund (“JAD predecessor fund”) into each respective share class of the Fund. Class T Shares of the Fund commenced operations on July 6, 2009.

• The performance shown for Class I Shares, Class A Shares, Class C Shares, and Class S Shares for periods prior to July 6, 2009, reflects the historical performance of the JAD predecessor fund’s Class I Shares, Class A Shares, Class C Shares and Class S Shares prior to the reorganization, calculated using the fees and expenses of each respective share class of the JAD predecessor fund, net of any applicable fee and expense limitations or waivers.

• The performance shown for Class T Shares for periods prior to July 6, 2009, reflects the historical performance of the JAD predecessor fund’s Class I Shares prior to the reorganization, calculated using the fees and expenses of Class T Shares, without the effect of any fee and expense limitations or waivers.

If Class T Shares of the Fund had been available during periods prior to July 6, 2009, the performance shown may have been different. The performance shown for periods following the Fund’s commencement of Class I Shares, Class A Shares, Class C Shares, Class S Shares, and Class T 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.

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

Best Quarter:  Second Quarter 2009  14.90%          Worst Quarter:  First Quarter 2009 -3.20%

The Fund’s year-to-date return as of the calendar quarter ended September 30, 2011 was -12.02%.

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

Average Annual Total Returns Janus World Allocation Fund Class A, C, S, I, T Shares	Column	Label		Index No Deduction for Fees, Expenses, Taxes [Text]	1 Year	Since Inception of Predecessor Fund	Inception Date
Return Before Taxes Class I	Class I Shares	Return Before Taxes			11.54%	3.74%	Sep. 03, 2008
Return Before Taxes Class A	Class A Shares	Return Before Taxes	[1]		5.12%	0.99%	Sep. 03, 2008
Return Before Taxes Class C	Class C Shares	Return Before Taxes	[2]		9.59%	3.02%	Sep. 03, 2008
Return Before Taxes Class S	Class S Shares	Return Before Taxes			11.02%	3.40%	Sep. 03, 2008
Return Before Taxes Class T	Class T Shares	Return Before Taxes			11.48%	3.63%	Sep. 03, 2008
Return After Taxes on Distributions Class I	Class I Shares	Return After Taxes on Distributions			10.61%	3.09%	Sep. 03, 2008
Return After Taxes on Distributions and Sale of Fund Shares Class I	Class I Shares	Return After Taxes on Distributions and Sale of Fund Shares	[3]		8.08%	2.93%	Sep. 03, 2008
Morgan Stanley Capital International All Country World Index℠ (net)		Morgan Stanley Capital International All Country World IndexSM (net)		(reflects no deduction for expenses, fees, or taxes)	12.67%	2.28%	Sep. 03, 2008
World Allocation Index		World Allocation Index		(reflects no deduction for expenses, fees, or taxes)	10.50%	4.46%	Sep. 03, 2008
Russell 3000® Index		Russell 3000® Index		(reflects no deduction for expenses, fees, or taxes)	17.64%	2.44%	Sep. 03, 2008
Dynamic Allocation Composite Index		Dynamic Allocation Composite Index		(reflects no deduction for expenses, fees, or taxes)	13.34%	4.31%	Sep. 03, 2008

Effective September 30, 2011, the Fund changed its primary benchmark index from the Russell 3000^® Index to the Morgan Stanley Capital International (“MSCI”) All Country World Index^SM. The MSCI All Country World Index^SM is an unmanaged, free float-adjusted, market capitalization weighted index composed of stocks of companies located in countries throughout the world. It is designed to measure equity market performance in global developed and emerging markets. The index includes reinvestment of dividends, net of foreign withholding taxes. In addition, the Fund changed its secondary benchmark index from the Dynamic Allocation Composite Index (which combined total returns from the Russell 3000^® Index (50%), the Barclays Capital U.S. Aggregate Bond Index (25%), and the MSCI All Country World ex-U.S. Index^SM (25%)) to the World Allocation Index. The World Allocation Index is an internally-calculated, hypothetical combination of unmanaged indices that combines total returns from the MSCI All Country World Index^SM (65%) and the Barclays Capital Global Aggregate Bond Index (35%). Janus Capital believes that these changes provide a more appropriate representation of the Fund’s investment strategy that includes an increased focus on global investments, including emerging markets.

After-tax returns are calculated using distributions for the Fund’s Class I Shares for periods following July 6, 2009; and for the JAD predecessor fund’s Class I Shares for periods prior to July 6, 2009. 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 I Shares of the Fund. After-tax returns for the other classes of Shares will vary from those shown for Class I Shares due to varying sales charges (as applicable), fees, and expenses among the classes.

[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 0.45% 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.

[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.