Summary Prospectus by Investment Company - Form 497K

Janus Henderson Mid Cap Value Portfolio

Ticker:

N/A

Service Shares

Summary Prospectus dated April 29, 2024

Before you invest, you may want to review the Portfolio's Prospectus, which contains more information about the Portfolio and its risks. You can find the Portfolio's Prospectus, reports to shareholders, and other information about the Portfolio online at janushenderson.com/VIT. You can also get this information at no cost by calling a Janus Henderson representative at 1-877-335-2687 or by sending an email request to [email protected].

Investment Objective

Janus Henderson Mid Cap Value Portfolio ("Mid Cap Value Portfolio") seeks capital appreciation.

Fees and Expenses of the Portfolio

This table describes the fees and expenses that you may pay if you buy, hold, and sell Shares of the Portfolio. Owners of variable insurance contracts that invest in the Shares should refer to the variable insurance contract prospectus for a description of fees and expenses, as the following table and examples do not reflect deductions at the separate account level or contract level for any charges that may be incurred under a contract. Inclusion of these charges would increase the fees and expenses described below.

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Management Fees(1)		0.50%
Distribution/Service (12b-1) Fees		0.25%
Other Expenses		0.18%
Total Annual Fund Operating Expenses		0.93%

EXAMPLE:

The Example is intended to help you compare the cost of investing in the Portfolio with the cost of investing in other mutual funds.The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated, reinvest all dividends and distributions, and then redeem all of your Shares at the end of each period. The Example also assumes that your investment has a 5% return each year and that the Portfolio's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 Year	3 Years	5 Years	10 Years
Service Shares	$95	$296	$515	$1,143

Portfolio Turnover:The Portfolio 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. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Portfolio's performance. During the most recent fiscal year, the Portfolio's turnover rate was 47% of the average value of its portfolio.

Principal investment strategies

The Portfolio pursues its investment objective by investing primarily in the common stocks of mid-sized companies and focuses on companies whose stock prices are believed to be undervalued by portfolio management or that have fallen out of favor with the market. The Portfolio invests, under normal circumstances, at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities of companies whose market capitalization falls, at the time of purchase, within the capitalization range of the Russell Midcap® Value Index. The market capitalizations within the index will vary, but as of December 31, 2023, they ranged from approximately $180 million to $59.18 billion. From time to time, the Portfolio may invest in shares of companies through initial public offerings. The Portfolio may also invest in foreign securities, as well as in real estate investment trusts ("REITs") and similar REIT-like entities.

As defensive value managers, portfolio management generally looks for companies with:

Portfolio management's philosophy is to weigh a security's downside risk before considering its upside potential, which may help provide an element of capital preservation.

Principal investment risks

The biggest risk is that the Portfolio's returns will vary, and you could lose money.The Portfolio 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. The principal risks associated with investing in the Portfolio are set forth below.

Market Risk.The value of the Portfolio's holdings may decrease due to short-term market movements and over more prolonged market downturns. As a result, the Portfolio's net asset value may fluctuate and it may be more difficult to value or sell the Portfolio's holdings. Market risk may affect a single issuer, industry, economic sector, or the market as a whole. Market risk may be magnified if certain social, political, economic, and other conditions and events (such as terrorism, conflicts, including related sanctions, social unrest, natural disasters, epidemics and pandemics, including COVID-19) adversely interrupt the global economy and financial markets. 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.

Value Investing Risk.Because different types of stocks tend to shift in and out of favor depending on market and economic conditions, "value" stocks may perform differently than other types of stocks and from the market as a whole, and can continue to be undervalued by the market for long periods of time. It is also possible that a value stock will never appreciate to the extent expected by portfolio management.

Mid-Sized Companies Risk.Investments in securities issued by mid-sized companies may involve greater risks than are customarily associated with larger, more established companies. For example, mid-sized companies may suffer more significant losses as a result of their narrow product lines, limited operating history, greater exposure to competitive threats, limited financial resources, limited trading markets, and the potential lack of management depth. Securities issued by mid-sized companies tend to be more volatile than securities issued by larger or more established companies and may underperform as compared to the securities of larger or more established companies. These holdings are also subject to wider price fluctuations and tend to be less liquid than stocks of larger or more established companies, which could have a significant adverse effect on the Portfolio's returns, especially as market conditions change.

Portfolio Management Risk.The Portfolio is an actively managed investment portfolio and is therefore subject to the risk that the investment strategies and research process employed for the Portfolio may fail to produce the intended results. Accordingly, the Portfolio may underperform its benchmark index or other mutual funds with similar investment objectives.

REIT Risk.REITs are subject to certain risks inherent in the direct ownership of real estate, including without limitation, a possible lack of mortgage funds and associated interest rate risks, overbuilding, property vacancies, increases in property taxes and operating expenses, changes in zoning laws, losses due to environmental damages and changes in neighborhood values and appeal to purchasers. In addition, a REIT could fail to qualify for tax-free pass-through of its income under the Internal Revenue Code of 1986, as amended, or fail to maintain its exemption from registration under the Investment Company Act of 1940, as amended, which could produce adverse economic consequences for the REIT and its investors, including the Portfolio. Dividends received by the Portfolio from a REIT generally will not constitute qualified dividend income.

Initial Public Offering Risk.The Portfolio's purchase of shares issued in an initial public offering ("IPO") exposes it to the risks associated with companies that have little operating history as public companies, as well as to the risks inherent in those sectors of the market where these new issuers operate. There can be no assurance that the Portfolio will identify favorable IPO investment opportunities.

Foreign Exposure Risk.Foreign markets can be more volatile than the U.S. market. As a result, the Portfolio's returns and net asset value may be affected by fluctuations in currency exchange rates or political or economic conditions in a particular country. In some foreign markets, there may not be protection against failure by other parties to complete transactions. It may not be possible for the Portfolio to repatriate capital, dividends, interest, and other income from a particular country or

governmental entity. In addition, a market swing in one or more countries or regions where the Portfolio has invested a significant amount of its assets may have a greater effect on the Portfolio's performance than it would in a more geographically diversified portfolio.

An investment in the Portfolio 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 Portfolio by showing how the Portfolio's performance has varied over time. The bar chart depicts the change in performance from year to year during the periods indicated. Total return figures include the effect of the Portfolio's expenses, but do not include charges or expenses attributable to any insurance product, which would lower the performance illustrated. The table compares the average annual returns for the Service Shares of the Portfolio for the periods indicated to a broad-based securities market index. All figures assume reinvestment of dividends and distributions. For certain periods, the Portfolio's performance reflects the effect of expense waivers. Without the effect of these expense waivers, the performance shown would have been lower.

The Portfolio's past performance does not necessarily indicate how it will perform in the future.Updated performance information is available at janushenderson.com/VITperformance or by calling 1-877-335-2687.

Annual Total Returns for Service Shares (calendar year-end)

Best Quarter:

4th Quarter 2020

18.15%

Worst Quarter:

1st Quarter 2020

- 29.16%

Average Annual Total Returns (periods ended 12/31/23)
	1 Year	5 Years	10 Years	Since Inception (12/31/02)
Mid Cap Value Portfolio
Service Shares	11.11%	9.94%	6.91%	9.20%
Russell Midcap® Value Index (reflects no deduction for fees, expenses, or taxes)	12.71%	11.16%	8.26%	10.48%

The Portfolio's primary benchmark index is the Russell Midcap Value Index. The index is described below.

Management

Investment Adviser: Janus Henderson Investors US LLC

Portfolio Management: Kevin Preloger is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since April 2013. Justin Tugman, CFA, is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since March 2015.

Purchase and sale of Portfolio shares

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Redemptions, like purchases, may be effected only through the separate accounts of participating insurance companies or through qualified retirement plans. Requests are duly processed at the NAV next calculated after an order is received in good order by the Portfolio or its agents. Refer to the appropriate separate account prospectus or plan documents for details.

Tax information

Because Shares of the Portfolio may be purchased only through variable insurance contracts and certain qualified retirement plans, it is anticipated that any income dividends or net capital gains distributions made by the Portfolio will be exempt from current federal income taxation if left to accumulate within the variable insurance contract or qualified retirement plan. The federal income tax status of your investment depends on the features of your qualified retirement plan or variable insurance contract.

Payments to Insurers, Broker-Dealers, and other financial intermediaries

Portfolio shares are generally available only through an insurer's variable contracts, or through certain employer or other retirement plans (Retirement Products). Retirement Products are generally purchased through a broker-dealer or other financial intermediary. The Portfolio or its distributor (or its affiliates) may make payments to the insurer and/or its related companies for distribution and/or other services; some of the payments may go to broker-dealers and other financial intermediaries. These payments may create a conflict of interest for an intermediary, or be a factor in the insurer's decision to include the Portfolio as an underlying investment option in a variable contract. Ask your financial advisor, visit your intermediary's website, or consult your insurance contract prospectus for more information.

Janus Henderson Mid Cap Value Portfolio

Ticker:

JAMVX

Institutional Shares

Summary Prospectus dated April 29, 2024

Before you invest, you may want to review the Portfolio's Prospectus, which contains more information about the Portfolio and its risks. You can find the Portfolio's Prospectus, reports to shareholders, and other information about the Portfolio online at janushenderson.com/VIT. You can also get this information at no cost by calling a Janus Henderson representative at 1-877-335-2687 or by sending an email request to [email protected].

Investment Objective

Janus Henderson Mid Cap Value Portfolio ("Mid Cap Value Portfolio") seeks capital appreciation.

Fees and Expenses of the Portfolio

This table describes the fees and expenses that you may pay if you buy, hold, and sell Shares of the Portfolio. Owners of variable insurance contracts that invest in the Shares should refer to the variable insurance contract prospectus for a description of fees and expenses, as the following table and examples do not reflect deductions at the separate account level or contract level for any charges that may be incurred under a contract. Inclusion of these charges would increase the fees and expenses described below.

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Management Fees(1)		0.50%
Other Expenses		0.19%
Total Annual Fund Operating Expenses		0.69%
Fee Waiver and/or Expense Reimbursement(2)		0.01%
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement(2)		0.68%

EXAMPLE:

The Example is intended to help you compare the cost of investing in the Portfolio with the cost of investing in other mutual funds.The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated, reinvest all dividends and distributions, and then redeem all of your Shares at the end of each period. The Example also assumes that your investment has a 5% return each year and that the Portfolio's operating expenses are equal to the Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement for the first year and the Total Annual Fund Operating Expenses thereafter. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 Year	3 Years	5 Years	10 Years
Institutional Shares	$69	$220	$383	$858

Portfolio Turnover:The Portfolio 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. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Portfolio's performance. During the most recent fiscal year, the Portfolio's turnover rate was 47% of the average value of its portfolio.

Principal investment strategies

The Portfolio pursues its investment objective by investing primarily in the common stocks of mid-sized companies and focuses on companies whose stock prices are believed to be undervalued by portfolio management or that have fallen out of favor with the market. The Portfolio invests, under normal circumstances, at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities of companies whose market capitalization falls, at the time of purchase, within the capitalization range of the Russell Midcap® Value Index. The market capitalizations within the index will vary, but as of

December 31, 2023, they ranged from approximately $180 million to $59.18 billion. From time to time, the Portfolio may invest in shares of companies through initial public offerings. The Portfolio may also invest in foreign securities, as well as in real estate investment trusts ("REITs") and similar REIT-like entities.

As defensive value managers, portfolio management generally looks for companies with:

Portfolio management's philosophy is to weigh a security's downside risk before considering its upside potential, which may help provide an element of capital preservation.

Principal investment risks

The biggest risk is that the Portfolio's returns will vary, and you could lose money.The Portfolio 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. The principal risks associated with investing in the Portfolio are set forth below.

Market Risk.The value of the Portfolio's holdings may decrease due to short-term market movements and over more prolonged market downturns. As a result, the Portfolio's net asset value may fluctuate and it may be more difficult to value or sell the Portfolio's holdings. Market risk may affect a single issuer, industry, economic sector, or the market as a whole. Market risk may be magnified if certain social, political, economic, and other conditions and events (such as terrorism, conflicts, including related sanctions, social unrest, natural disasters, epidemics and pandemics, including COVID-19) adversely interrupt the global economy and financial markets. 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.

Value Investing Risk.Because different types of stocks tend to shift in and out of favor depending on market and economic conditions, "value" stocks may perform differently than other types of stocks and from the market as a whole, and can continue to be undervalued by the market for long periods of time. It is also possible that a value stock will never appreciate to the extent expected by portfolio management.

Mid-Sized Companies Risk.Investments in securities issued by mid-sized companies may involve greater risks than are customarily associated with larger, more established companies. For example, mid-sized companies may suffer more significant losses as a result of their narrow product lines, limited operating history, greater exposure to competitive threats, limited financial resources, limited trading markets, and the potential lack of management depth. Securities issued by mid-sized companies tend to be more volatile than securities issued by larger or more established companies and may underperform as compared to the securities of larger or more established companies. These holdings are also subject to wider price fluctuations and tend to be less liquid than stocks of larger or more established companies, which could have a significant adverse effect on the Portfolio's returns, especially as market conditions change.

Portfolio Management Risk.The Portfolio is an actively managed investment portfolio and is therefore subject to the risk that the investment strategies and research process employed for the Portfolio may fail to produce the intended results. Accordingly, the Portfolio may underperform its benchmark index or other mutual funds with similar investment objectives.

REIT Risk.REITs are subject to certain risks inherent in the direct ownership of real estate, including without limitation, a possible lack of mortgage funds and associated interest rate risks, overbuilding, property vacancies, increases in property taxes and operating expenses, changes in zoning laws, losses due to environmental damages and changes in neighborhood values and appeal to purchasers. In addition, a REIT could fail to qualify for tax-free pass-through of its income under the Internal Revenue Code of 1986, as amended, or fail to maintain its exemption from registration under the Investment Company Act of 1940, as amended, which could produce adverse economic consequences for the REIT and its investors, including the Portfolio. Dividends received by the Portfolio from a REIT generally will not constitute qualified dividend income.

Initial Public Offering Risk.The Portfolio's purchase of shares issued in an initial public offering ("IPO") exposes it to the risks associated with companies that have little operating history as public companies, as well as to the risks inherent in those

sectors of the market where these new issuers operate. There can be no assurance that the Portfolio will identify favorable IPO investment opportunities.

Foreign Exposure Risk.Foreign markets can be more volatile than the U.S. market. As a result, the Portfolio's returns and net asset value may be affected by fluctuations in currency exchange rates or political or economic conditions in a particular country. In some foreign markets, there may not be protection against failure by other parties to complete transactions. It may not be possible for the Portfolio to repatriate capital, dividends, interest, and other income from a particular country or governmental entity. In addition, a market swing in one or more countries or regions where the Portfolio has invested a significant amount of its assets may have a greater effect on the Portfolio's performance than it would in a more geographically diversified portfolio.

An investment in the Portfolio 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 Portfolio by showing how the Portfolio's performance has varied over time. The bar chart depicts the change in performance from year to year during the periods indicated. Total return figures include the effect of the Portfolio's expenses, but do not include charges or expenses attributable to any insurance product, which would lower the performance illustrated. The table compares the average annual returns for the Institutional Shares of the Portfolio for the periods indicated to a broad-based securities market index. All figures assume reinvestment of dividends and distributions. For certain periods, the Portfolio's performance reflects the effect of expense waivers. Without the effect of these expense waivers, the performance shown would have been lower.

The Portfolio's past performance does not necessarily indicate how it will perform in the future.Updated performance information is available at janushenderson.com/VITperformance or by calling 1-877-335-2687.

Annual Total Returns for Institutional Shares (calendar year-end)

Best Quarter:

4th Quarter 2020

18.29%

Worst Quarter:

1st Quarter 2020

- 29.11%

Average Annual Total Returns (periods ended 12/31/23)
	1 Year	5 Years	10 Years	Since Inception (5/1/03)
Mid Cap Value Portfolio
Institutional Shares	11.40%	10.22%	7.18%	9.63%
Russell Midcap® Value Index (reflects no deduction for fees, expenses, or taxes)	12.71%	11.16%	8.26%	10.50%

The Portfolio's primary benchmark index is the Russell Midcap Value Index. The index is described below.

Management

Investment Adviser: Janus Henderson Investors US LLC

Portfolio Management: Kevin Preloger is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since April 2013. Justin Tugman, CFA, is Executive Vice President and Co-Portfolio Manager of the Portfolio, which he has co-managed since March 2015.

Purchase and sale of Portfolio shares

Purchases of Shares may be made only by the separate accounts of insurance companies for the purpose of funding variable insurance contracts or by certain qualified retirement plans. Redemptions, like purchases, may be effected only through the separate accounts of participating insurance companies or through qualified retirement plans. Requests are duly processed at the NAV next calculated after an order is received in good order by the Portfolio or its agents. Refer to the appropriate separate account prospectus or plan documents for details.

Tax information

Because Shares of the Portfolio may be purchased only through variable insurance contracts and certain qualified retirement plans, it is anticipated that any income dividends or net capital gains distributions made by the Portfolio will be exempt from current federal income taxation if left to accumulate within the variable insurance contract or qualified retirement plan. The federal income tax status of your investment depends on the features of your qualified retirement plan or variable insurance contract.

Payments to Insurers, Broker-Dealers, and other financial intermediaries

Portfolio shares are generally available only through an insurer's variable contracts, or through certain employer or other retirement plans (Retirement Products). Retirement Products are generally purchased through a broker-dealer or other financial intermediary. The Portfolio or its distributor (or its affiliates) may make payments to the insurer and/or its related companies for distribution and/or other services; some of the payments may go to broker-dealers and other financial intermediaries. These payments may create a conflict of interest for an intermediary, or be a factor in the insurer's decision to include the Portfolio as an underlying investment option in a variable contract. Ask your financial advisor, visit your intermediary's website, or consult your insurance contract prospectus for more information.