497K - NVIT DoubleLine Total Return Tactical

NVIT DoubleLine Total Return Tactical Fund

Summary Prospectus April 30, 2026

Class I / Class II / Class Y

Before you invest, you may want to review the Fund’s Prospectus, which contains information about the Fund and its risks. This Summary Prospectus is intended for use in connection with variable insurance contracts, and is not intended for use by other investors. The Fund’s Prospectus and Statement of Additional Information, each dated April 30, 2026 (as may be supplemented or revised), are incorporated by reference into this Summary Prospectus. For free paper or electronic copies of the Fund’s Prospectus and other information about the Fund, go to nationwide.com/mutualfundsnvit, email a request to web_help@nationwide.com or call 800-848-0920, or ask any variable insurance contract provider who offers shares of the Fund as an underlying investment option in its products.

Objective

The NVIT DoubleLine Total Return Tactical Fund seeks to maximize total return.

Fees and Expenses

This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. Sales charges and other expenses that may be imposed by variable insurance contracts are not included. If these charges were reflected, the expenses listed below would be higher. See the variable insurance contract prospectus, which may impose sales charges and other additional contract-level expenses.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Class I Shares	Class II Shares	Class Y Shares
Management Fees	0.58%	0.58%	0.58%
Distribution and/or Service (12b-1) Fees	None	0.25%	None
Other Expenses	0.44%	0.44%	0.19%
Total Annual Fund Operating Expenses	1.02%	1.27%	0.77%
Fee Waiver/Expense Reimbursement(1),(2)	(0.19)%	(0.29)%	(0.19)%
Total Annual Fund Operating Expenses After Fee Waiver/Expense Reimbursement	0.83%	0.98%	0.58%

(1) Nationwide Variable Insurance Trust (the “Trust”) and Nationwide Fund Advisors (the “Adviser”) have entered into a written contract limiting annual fund operating expenses to 0.58% until at

least April 30, 2027. Under the expense limitation agreement, the level to which operating expenses are limited applies to all share classes, excluding any taxes, interest, compensation payable

to parties not affiliated with the Adviser for the recovery of tax reclaims, brokerage commissions, Rule 12b-1 fees, acquired fund fees and expenses, short-sale dividend expenses, administrative services fees, other expenses which are capitalized in accordance with generally accepted accounting principles and expenses incurred by the Fund in connection with any merger or reorganization, and may exclude other nonroutine expenses not incurred in the ordinary course of the Fund’s business. The expense limitation agreement may be changed or eliminated only with the consent of the Board of Trustees of the Trust. The Adviser may request and receive reimbursement from the Fund for advisory fees waived or other expenses reimbursed by the Adviser pursuant to the expense limitation agreement at a date not to exceed three years from the date on which the corresponding waiver or reimbursement to the Fund was made. However, no reimbursement may be made unless: (i) the Fund’s assets exceed $100 million and (ii) the total annual expense ratio is no higher than the amount of the expense limitation that was in place at the time the Adviser waived the fees or reimbursed the expenses and does not cause the expense ratio to exceed the current expense limitation. Reimbursement by the Fund of amounts previously waived or reimbursed by the Adviser is not permitted except as provided for in the expense limitation agreement.

(2) The Trust and Nationwide Fund Distributors LLC have entered into a written contract waiving 0.10% of the Distribution and/or Service (12b-1) Fees for Class II shares until April 30, 2027. The written contract may be changed or eliminated only with the consent of the Board of Trustees of the Trust.

Example

This Example is intended to help you to compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example, however, does not include charges that are imposed by variable insurance contracts. If these charges were reflected, the expenses listed below would be higher.

This Example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of those time periods. It assumes a 5% return each year and no change in expenses, and any expense limitation or fee waivers

NSP-TRT (4/26)

Summary Prospectus April 30, 2026

NVIT DoubleLine Total Return Tactical Fund

that may apply for the periods indicated above under “Fees and Expenses.” 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
Class I Shares	$85	$306	$545	$1,231
Class II Shares	100	374	669	1,508
Class Y Shares	59	227	409	936

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. 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 34.94% of the average value of its portfolio.

Principal Investment Strategies

The Fund employs a flexible investment approach, allocating across different types of fixed-income, or debt, securities. Consistent with this approach, the Fund may invest in U.S. government securities and foreign government bonds, for example, as well as U.S. and foreign corporate bonds, asset-backed securities and mortgage-backed securities. The Fund also may invest in corporate loans. Securities in which the Fund invests pay interest on either a fixed-rate or variable-rate basis. The Fund may invest in securities issued by foreign issuers, including those that are located in emerging market countries, although, under normal circumstances, the Fund does not invest more than 25% of its net assets, at the time of purchase, in emerging market securities. Emerging market countries typically are developing and low- or middle-income countries, and include certain countries located in Latin America, Asia, Africa, the Middle East and Eastern Europe. The Fund may invest without limit in foreign securities that are denominated in U.S. dollars, although the Fund may invest up to 15% of its net assets, at the time of purchase, in securities that are denominated in currencies other than the U.S. dollar.

The Fund invests in mortgage-backed securities. Mortgage-backed securities include either pass-through securities issued by U.S. government agencies, such as Ginnie Mae, Fannie Mae or Freddie Mac, or collateralized mortgage obligations issued either by U.S. government agencies or by private issuers. The Fund may purchase many U.S. agency pass-through securities on a when-issued (also known as “to-be-announced”) basis, and it may also purchase or sell such securities for delayed delivery. When entering into such a transaction, the Fund buys or sells securities with payment and delivery scheduled to take place in the future. The Fund may invest in mortgage-backed securities—either U.S. agency or privately-issued—of any credit quality. Nevertheless, the Fund normally invests at least 20% of its net assets, at the time of purchase, in mortgage-backed securities that are rated, at the time of investment, Aa3 or higher by Moody’s Investor Service, Inc., AA- or higher by Standard & Poor’s Rating Service; the equivalent by any other nationally recognized statistical rating organization (“NRSRO”); or, if unrated by an NRSRO, determined by the subadviser to be of comparable quality.

The Fund may invest up to 25% of its net assets, at the time of purchase, in corporate high-yield bonds (i.e., “junk bonds”). Some of these debt securities may be in default or at high risk of defaulting, and may have extremely poor prospects for being able to make principal and interest payments. The Fund’s subadviser strives to allocate below investment grade securities broadly by industry and issuer in an attempt to reduce the impact of negative events on an industry or issuer. Under normal conditions, the combined total of corporate, sovereign, mortgage-backed and all other debt rated below investment grade will not exceed 40% of the Fund’s assets.

The Fund’s subadviser actively manages the Fund’s asset class exposure using a top-down approach based on analysis of sector fundamentals and rotates the Fund’s assets among sectors in various markets to attempt to maximize total return. The subadviser may use futures, which are derivatives, to manage the Fund’s duration and yield curve exposure.

The subadviser selects individual securities within asset classes using a bottom-up approach, which involves the selection of securities based on their individual attributes regardless of broader national or economic factors. Under normal circumstances, the subadviser uses a controlled risk approach in managing the Fund’s investments. The techniques of this approach attempt to control the principal risk components of the fixed-income markets. The subadviser may sell a security for various reasons, such as to adjust the Fund’s average maturity or quality, to shift assets into better-yielding securities, or to alter sector exposure. The Fund may engage in active and frequent trading of portfolio securities.

The Fund is classified as a “nondiversified fund” under the Investment Company Act of 1940, which means that a relatively high percentage of the Fund’s assets may be invested in a limited number of issuers.

Summary Prospectus April 30, 2026

NVIT DoubleLine Total Return Tactical Fund

Principal Risks

The Fund cannot guarantee that it will achieve its investment objective.

As with any fund, the value of the Fund’s investments—and therefore, the value of Fund shares—may fluctuate. These changes may occur because of:

Market risk – the risk that one or more markets in which the Fund invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. This occurs due to numerous factors, including interest rates, the outlook for corporate profits, the health of the national and world economies, and the fluctuation of other securities markets around the world. These risks may be magnified if certain social, political, economic and other conditions and events (such as natural disasters, epidemics and pandemics, terrorism, conflicts, trade disputes and social unrest or rapid technological developments such as artificial intelligence) adversely interrupt the global economy.

Selection risk – the risk that the securities selected by the Fund’s subadviser will underperform the markets, the relevant indexes or the securities selected by other funds with similar investment objectives and investment strategies.

Interest rate risk – generally, when interest rates go up, the value of debt securities goes down. Prices of longer-term securities generally change more in response to interest rate changes than prices of shorter-term securities. To the extent the Fund invests a substantial portion of its assets in debt securities with longer-term maturities, rising interest rates are more likely to cause periods of increased volatility and redemptions, and will cause the value of the Fund's investments to decline significantly. The Federal Reserve Board continued to lower interest rates following a period of consistent rate increases, though it is unclear if such lowering will continue. The interest earned on the Fund's investments in debt securities may decline when prevailing interest rates fall. Declines in interest rates increase the likelihood that debt obligations will be pre-paid, which, in turn, increases these risks. Very low or negative interest rates will impact the yield of the Fund's investments in debt securities and increase the risk that, if followed by rising interest rates, the Fund's performance will be negatively impacted. The Fund is subject to the risk that the income generated by its investments in debt securities may not keep pace with inflation. Recent and potential future changes in government policy may affect interest rates.

The interest rate of fixed-rate securities is fixed at the time of purchase and does not fluctuate with general market conditions. Floating-rate securities have interest rates that vary with changes to a specific measure, such as the Treasury bill rate. Variable-rate securities have interest rates that change at preset times based on changes on the specific measure.

Credit risk – a bond issuer will default if it is unable to pay the interest or principal when due. If an issuer defaults, the Fund will lose money. This risk is particularly high for high-yield bonds and other securities rated below investment grade. Changes in a bond issuer’s credit rating or the market’s perception of an issuer’s creditworthiness also affect the market price of a bond.

High-yield bonds risk – investing in high-yield bonds (i.e., “junk bonds”) and other lower-rated bonds is considered speculative and may subject the Fund to substantial risk of loss due to issuer default, decline in market value due to adverse economic and business developments, sensitivity to changing interest rates, or lack of liquidity.

Prepayment and call risk – certain bonds will be paid off by the issuer more quickly than anticipated. If this happens, the Fund may be required to invest the proceeds in securities with lower yields.

Mortgage-backed and asset-backed securities risks – these securities generally are subject to the same types of risk that apply to other debt securities, such as interest rate risk, credit risk, and prepayment and call risk. Mortgage-backed securities also are subject to extension risk, which is the risk that when interest rates rise, certain mortgage-backed securities will be paid in full by the issuer more slowly than anticipated. This can cause the market value of the security to fall because the market may view its interest rate as low for a longer-term investment. Through its investments in mortgage-backed securities, the Fund may have some exposure to subprime loans, as well as to the mortgage and credit markets generally. Subprime loans, which are loans made to borrowers with weakened credit histories, generally have higher default rates than loans that meet government underwriting requirements. The credit quality of most asset-backed securities depends primarily on the credit quality of the assets underlying such securities, how well the entity issuing the security is insulated from the credit risk of the originator or any other affiliated entities, and the amount and quality of any credit enhancement of the securities.

Collateralized mortgage obligations risk – collateralized mortgage obligations exhibit similar risks to those of mortgage-backed securities but also present certain special risks. Collateralized mortgage obligations are created by dividing the principal and interest payments collected on a pool of mortgages into several revenue streams (tranches) with different priority rights to portions of the underlying mortgage payments. Collateralized mortgage obligation tranches often are specially structured in a manner that provides a variety of investment characteristics, such as yield, effective maturity and interest rate sensitivity. As market conditions change, however, particularly during periods of rapid or unanticipated changes in interest rates, the ability of a collateralized mortgage obligation tranche to provide the anticipated investment characteristics and performance may

Summary Prospectus April 30, 2026

NVIT DoubleLine Total Return Tactical Fund

be significantly reduced. These changes may result in volatility in the market value, and in some instances reduced liquidity, of the collateralized mortgage obligation tranche.

Foreign securities risk – foreign securities often are more volatile, harder to price and less liquid than U.S. securities. The prices of foreign securities may be further affected by other factors, such as changes in the exchange rates between the U.S. dollar and the currencies in which the securities are traded.

Foreign currencies – foreign securities may be denominated or quoted in currencies other than the U.S. dollar. Changes in foreign currency exchange rates affect the value of the Fund’s portfolio. Generally, when the U.S. dollar rises in value against a foreign currency, a security denominated in that currency loses value because the currency is worth fewer U.S. dollars. Conversely, when the U.S. dollar decreases in value against a foreign currency, a security denominated in that currency gains value because the currency is worth more U.S. dollars.

Emerging markets risk – emerging markets are riskier than more developed markets because they tend to develop unevenly and may never fully develop. Investments in emerging markets are considered speculative. Emerging markets are more likely to experience hyperinflation and currency devaluations, which adversely affect returns to U.S. investors. In addition, many emerging securities markets have far lower trading volumes and less liquidity than developed markets. Since these markets are smaller than developed markets, they may be more likely to suffer sharp and frequent price changes or long-term price depression because of adverse publicity, investor perceptions or the actions of a few large investors. Practices in relation to settlement of securities transactions in emerging markets involve higher risks than those in developed markets, in part because the Fund will need to use brokers and counterparties that are less well capitalized, and custody and registration of assets in some countries are unreliable compared to developed markets. Companies in emerging market countries generally are subject to less stringent financial reporting, accounting and auditing standards than companies in more developed countries. In addition, information about such companies may be less available and reliable. Many emerging markets also have histories of political instability and abrupt changes in policies, and the ability to bring and enforce actions may be limited. Certain emerging markets also face other significant internal or external risks, including the risk of war, nationalization of assets, unexpected market closures and ethnic, religious and racial conflicts.

Sovereign debt risk – sovereign debt instruments are subject to the risk that a governmental entity will delay or refuse to pay interest or repay principal on its sovereign debt due, for example, to cash flow problems, insufficient foreign currency reserves, political considerations, the relative size of the governmental entity’s debt position in relation to the economy or the failure to put in place economic reforms required by the International Monetary Fund or other multilateral agencies.

Corporate loans risk – commercial banks and other financial institutions or institutional investors make corporate loans to companies that need capital to grow or restructure. Borrowers generally pay interest on corporate loans at rates that change in response to changes in market interest rates or the prime rates of U.S. banks. The market for corporate loans may be subject to irregular trading activity, wide bid/ask spreads (difference between the highest price a buyer is willing to pay for an asset and the lowest price that a seller is willing to accept for an asset) and extended trade settlement periods. Corporate loans have speculative characteristics and high risk, and often are referred to as “junk.” Furthermore, investments in corporate loans may not be considered “securities” for certain federal securities laws, and therefore the Fund may not be able to rely on the antifraud protections of the federal securities laws.

Delayed-delivery risk – the risk that the security the Fund buys will lose value prior to its delivery or that the seller will not meet its obligation. If this happens, the Fund will lose the investment opportunity for the assets it set aside to pay for the security and any gain in the security’s price.

To-be-announced transactions (“TBAs”) – TBAs involve the risk of loss if the securities received are less favorable than what was anticipated by the Fund when entering into the TBA, or if the counterparty fails to deliver the securities. When the Fund enters into a short sale of a TBA mortgage it does not own, the Fund may have to purchase deliverable mortgages to settle the short sale at a higher price than anticipated, thereby causing a loss. As there is no limit on how much the price of mortgage securities can increase, the Fund’s exposure is unlimited. The Fund may not always be able to purchase mortgage securities to close out the short position at a particular time or at an acceptable price. In addition, taking short positions results in a form of leverage, which could increase the volatility of the Fund’s share price.

Dollar roll transactions – dollar roll transactions occur in connection with TBAs and involve the risk that the market value of the securities the Fund is required to purchase may decline below the agreed upon purchase price of those securities. Dollar roll transactions add a form of leverage to the Fund’s portfolio, which may make the Fund’s returns more volatile and increase the risk of loss. In addition, dollar roll transactions may increase the Fund’s portfolio turnover, which may result in increased brokerage costs and may lower the Fund’s actual return.

Derivatives risk – derivatives may be volatile and may involve significant risks. The underlying security, measure or other instrument on which a derivative is based, or the derivative itself, may not perform as expected. Normally derivatives involve leverage, which means that their use can magnify significantly the effect of price movements of the underlying securities or reference measures, disproportionately increasing the Fund’s losses and reducing the Fund’s opportunities for gains. Some derivatives have the potential for unlimited loss,

Summary Prospectus April 30, 2026

NVIT DoubleLine Total Return Tactical Fund

including a loss that may be greater than the amount invested. They also present default risks if the counterparty to a derivatives contract fails to fulfill its obligations to the Fund. Certain derivatives held by the Fund may be illiquid, making it difficult to close out an unfavorable position. Derivatives also may be more difficult to purchase, sell or value than other instruments.

Futures – the prices of futures contracts typically are more volatile than those of stocks and bonds. Small movements in the values of the assets or measures of underlying futures contracts can cause disproportionately larger losses to the Fund. While futures may be more liquid than other types of derivatives, they may experience periods when they are less liquid than stocks, bonds or other investments.

Liquidity risk – when there is little or no active trading market for specific types of securities or instruments, it can become more difficult to sell the securities or instruments at or near their perceived value. An inability to sell a portfolio position can adversely affect the Fund's value or prevent the Fund from being able to take advantage of other investment opportunities. Liquidity risk also includes the risk that the Fund will experience significant net redemptions of its shares at a time when it cannot find willing buyers for its portfolio securities or instruments or can sell its portfolio securities or instruments only at a material loss. To meet redemption requests, the Fund may be forced to sell other securities or instruments that are more liquid, but at unfavorable times and conditions. Investments in foreign securities and high-yield bonds tend to have more exposure to liquidity risk than domestic securities and higher-rated bonds.

U.S. government securities risk – not all obligations of the U.S. government, its agencies and instrumentalities are backed by the full faith and credit of the United States. Some obligations are backed only by the credit of the issuing agency or instrumentality, and in some cases there is some risk of default by the issuer. Even if a security is backed by the U.S. Treasury or the full faith and credit of the United States, such guarantee applies only to the timely payment of interest and principal. Neither the U.S. government nor its agencies guarantee the market value of their securities, and interest rate changes, prepayments and other factors will affect the value of U.S. government securities. It is possible that issuers of U.S. government securities will not have the funds to meet their payment obligations in the future.

Nondiversified fund risk – because the Fund may hold larger positions in fewer securities and financial instruments than diversified funds, a single security’s or instrument's increase or decrease in value may have a greater impact on the Fund’s value and total return.

Portfolio turnover risk – a higher portfolio turnover rate increases transaction costs and may adversely impact the Fund’s performance.

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

Performance

The following bar chart and table provide some indication of the risks of investing in the Fund. The bar chart shows the volatility or variability of the Fund’s annual total returns over time and shows that Fund performance can change from year to year. The table shows the Fund’s average annual total returns for certain time periods compared to the returns of a broad-based securities market index. Remember, however, that past performance is not necessarily an indication of how the Fund will perform in the future. The returns shown in the bar chart and table do not include charges that will be imposed by variable insurance contracts. If these amounts were reflected, returns would be less than those shown.

Annual Total Returns– Class I
(Years Ended December 31,)

Highest Quarter:	6.36%	–	4Q 2023
Lowest Quarter:	-5.30%	–	2Q 2022

Average Annual Total Returns
(For the Periods Ended December 31, 2025)

	1 Year	5 Years	Since Fund Inception	Fund Inception Date
Class I Shares	7.60%	0.60%	1.69%	10/16/2017
Class II Shares	7.31%	0.22%	1.40%	10/16/2017
Class Y Shares	7.69%	0.62%	1.79%	10/16/2017
Bloomberg U.S. Aggregate Bond Index (reflects no deduction for fees or expenses)	7.30%	-0.36%	1.70%

Summary Prospectus April 30, 2026

NVIT DoubleLine Total Return Tactical Fund

Portfolio Management

Investment Adviser

Nationwide Fund Advisors

Subadviser

DoubleLine Capital LP

Portfolio Managers

Portfolio Manager	Title	Length of Service with Fund
Jeffrey E. Gundlach	Chief Executive Officer & Chief Investment Officer	Since 2017
Jeffrey J. Sherman, CFA	Deputy Chief Investment Officer	Since 2017

Tax Information

The dividends and distributions paid by the Fund to the insurance company separate accounts will consist of ordinary income, capital gains, or some combination of both. Because shares of the Fund must be purchased through separate accounts used to fund variable insurance contracts, such dividends and distributions will be exempt from current taxation by contract holders if left to accumulate within a separate account. Consult the variable insurance contract prospectus for additional tax information.

Payments to Broker-Dealers and Other Financial Intermediaries

This Fund is only offered as an underlying investment option for variable insurance contracts. The Fund and its related companies may make payments to the sponsoring insurance companies (or their affiliates) for distribution and/or other services, and to broker-dealers and other financial intermediaries that distribute the variable insurance contracts. These payments may create a conflict of interest by influencing the insurance companies to include the Fund as an underlying investment option in the variable insurance contracts, and by influencing the broker-dealers and other financial intermediaries to distribute variable insurance contracts that include the Fund as an underlying investment option over other variable insurance contracts or to otherwise recommend the selection of the Fund as an underlying investment option by contract owners instead of other funds that also may be available investment options. The prospectus (or other offering document) for your variable insurance contract may contain additional information about these payments.

Summary Prospectus April 30, 2026

NVIT DoubleLine Total Return Tactical Fund