INTECH U.S. Core Fund | Class A, C, S, I, T Shares

Fund summary

INTECH U.S. Core Fund

INVESTMENT OBJECTIVE

INTECH U.S. Core Fund seeks long-term growth of capital.

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 46 of the Fund’s Prospectus and in the “Purchases” section on page 83 of the Fund’s Statement of Additional Information.

SHAREHOLDER FEES
(fees paid directly from your investment)

Shareholder Fees INTECH U.S. Core 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 INTECH U.S. Core 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 (may adjust up or down)	0.54%	0.54%	0.54%	0.54%	0.54%
Distribution/Service (12b-1) Fees	0.25%	1.00%	0.25%	none	none
Other Expenses	0.20%	0.29%	0.37%	0.18%	0.37%
Total Annual Fund Operating Expenses	0.99%	1.83%	1.16%	0.72%	0.91%

EXAMPLE:

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 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 INTECH U.S. Core 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	670	872	1,091	1,718
Class C	Class C Shares	286	576	990	2,148
Class S	Class S Shares	118	368	638	1,409
Class I	Class I Shares	74	230	401	894
Class T	Class T Shares	93	290	504	1,120

If Shares are not redeemed:

Expense Example, No Redemption INTECH U.S. Core 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	670	872	1,091	1,718
Class C	Class C Shares	186	576	990	2,148
Class S	Class S Shares	118	368	638	1,409
Class I	Class I Shares	74	230	401	894
Class T	Class T Shares	93	290	504	1,120

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 year, the Fund’s portfolio turnover rate was 73% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

The Fund invests, under normal circumstances, at least 80% of its net assets in U.S. common stocks from the universe of the S&P 500^® Index, utilizing INTECH’s mathematical investment process. The S&P 500^® Index is an unmanaged index of 500 stocks that is generally representative of the performance of larger companies in the United States.

The Fund pursues its investment objective by applying a mathematical investment process to construct an investment portfolio from the universe of common stocks within its named benchmark index. The goal of this process is to build a portfolio of stocks in a more efficient combination than the named benchmark index. The process seeks to capitalize on the natural volatility of the market by searching for stocks within the index that have high relative volatility (providing the potential for excess returns) but that essentially move in opposite directions or have low correlation to each other (providing the potential for lower relative risk). By constructing the portfolio in this manner and periodically rebalancing the portfolio to maintain potentially more efficient weightings, INTECH’s mathematical investment process seeks to create a portfolio that, over time, produces returns in excess of its named benchmark index with risks similar to that of the benchmark index. The rebalancing techniques used by INTECH may result in a higher portfolio turnover compared to a “buy and hold” fund strategy.

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 an equity portfolio, including common stocks. Common stocks tend to be more volatile than many other investment choices.

Market Risk. The value of the Fund’s portfolio may decrease if the value of an individual company or security, or multiple companies or securities, in the portfolio decreases. Further, regardless of how well individual companies or securities perform, the value of the 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.

Investment Process Risk. The proprietary mathematical investment process used by INTECH may not achieve the desired results. On an occasional basis, INTECH considers changes to its mathematical investment process. These changes may result in changes to the portfolio, might not provide the intended results, and may adversely impact the Fund’s performance.

Portfolio Turnover Risk. Increased portfolio turnover may result in higher costs, which may have a negative effect on the Fund’s performance. In addition, higher portfolio turnover may result in the acceleration of capital gains and the recognition of greater levels of short-term capital gains, which are taxed at ordinary federal income tax rates when distributed to shareholders.

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 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, and Class S 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.
•   The performance shown for 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 Class J Shares, net of any applicable 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. 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 a broad-based securities market index. The index is not actively managed and is 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 T Shares (calendar year-end)

Best Quarter:  Second Quarter 2009  14.79%     Worst Quarter:   Fourth Quarter 2008  −21.49%

The Fund’s year-to-date return as of the calendar quarter ended September 30, 2012 was 14.92%.

Average Annual Total Returns (periods ended 12/31/11)

Average Annual Total Returns INTECH U.S. Core Fund Class A, C, S, I, T Shares	Column	Label		1 Year	5 Years	Since Inception	Inception Date
Class T Shares Return Before Taxes	Class T Shares	Return Before Taxes		4.97%	0.25%	7.79%	Feb. 28, 2003
Class T Shares Return After Taxes on Distributions	Class T Shares	Return After Taxes on Distributions		4.83%	(0.23%)	7.07%	Feb. 28, 2003
Class T Shares Return After Taxes on Distributions and Sale of Fund Shares	Class T Shares	Return After Taxes on Distributions and Sale of Fund Shares	[1]	3.42%	0.18%	6.72%	Feb. 28, 2003
Class A Shares Return Before Taxes	Class A Shares	Return Before Taxes	[2]	(1.16%)	(1.16%)	6.78%	Feb. 28, 2003
Class C Shares Return Before Taxes	Class C Shares	Return Before Taxes	[3]	2.99%	(0.72%)	6.71%	Feb. 28, 2003
Class S Shares Return Before Taxes	Class S Shares	Return Before Taxes		4.71%	(0.14%)	7.31%	Feb. 28, 2003
Class I Shares Return Before Taxes	Class I Shares	Return Before Taxes		5.18%	0.25%	7.79%	Feb. 28, 2003
S&P 500 Index (reflects no deduction for expenses, fees, or taxes)		S&P 500® Index		2.11%	(0.25%)	6.77%	Feb. 28, 2003

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.

[1] 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.

[2] Calculated assuming maximum permitted sales loads.

[3] The one year return is calculated to include the contingent deferred sales charge.