Estate Tax Portability and Why Most States Don’t Offer It

Losing a spouse is emotionally devastating, but many families are shocked to discover a secondary blow: a massive tax bill because they didn't understand "portability." While the federal government allows a surviving spouse to inherit their partner's unused tax exemption, most states do not. This guide clarifies the complexities of estate tax portability and provides actionable strategies to protect your hard-earned legacy from state-level tax traps.

Understanding the Concept of Estate Tax Portability

When we talk about estate planning, the word "portability" sounds like something involving a mobile phone plan or a transferable job benefit. In reality, it is one of the most powerful tools for married couples to shield their assets from the IRS. Essentially, portability allows a surviving spouse to "pick up" whatever part of the federal estate tax exemption their deceased spouse didn't use. Without this, that exemption might simply vanish into thin air upon the first spouse's death, leaving the survivor with a much larger taxable estate than necessary.

It is a common misconception that because you are married, everything you own is automatically protected. While the unlimited marital deduction allows you to pass assets to a spouse tax-free, it doesn't solve the problem of what happens when that second spouse eventually passes away. If the first spouse didn't use their exemption, the second spouse’s estate could end up being worth far more than their individual exemption limit. This is where Federal Estate Tax Portability and DSUE Explained becomes the hero of the story, as it effectively doubles the amount a couple can leave to their children or other heirs without paying a dime in federal taxes.

However, the "friendly" nature of federal law often lulls people into a false sense of security. We often assume that state laws will mirror federal ones, but that is rarely the case with estate taxes. In the world of state-level planning, portability is the exception rather than the rule. Understanding the mechanics of how this works at a high level is the first step in realizing why your current "simple" will might be leaving a massive door open for state tax collectors to walk through later.

What is Portability Exactly at the Federal Level

At its core, federal portability is a relatively modern convenience. Before 2010, if a husband died and left everything to his wife, his individual estate tax exemption was essentially wasted because he didn't "use" it to pass assets to anyone else (since the transfer to the wife was already tax-free under the marital deduction). To save that exemption, couples had to set up complex trusts. Today, the IRS says that as long as you file the right paperwork, the surviving spouse can add the deceased spouse's unused exemption to their own.

Think of it like a "rollover" for tax credits. If the federal exemption is $15,000,000 and the first spouse dies leaving everything to the survivor, that $15,000,000 doesn’t have to disappear. By making a portability election, the survivor now has their own $15,000,000 plus the $15,000,000 from their late spouse, totaling $30,000,000 in protection. This is a massive safety net for high-net-worth families, but it requires proactive filing, even if no tax is owed at the time of the first death.

The beauty of federal portability is that it simplifies life for many couples who don't want to deal with restrictive trusts while they are still healthy and active. It allows for a "wait and see" approach. You can use a tool like SmartAsset to model your potential growth and see if your combined assets might exceed these thresholds in the future. But remember, this federal "gift" of portability is not a universal right across all jurisdictions.

The Deceased Spousal Unused Exclusion

The technical term you’ll see on IRS forms is the Deceased Spousal Unused Exclusion, or DSUE. This is the specific dollar amount that is "ported" over. Calculating the DSUE is usually straightforward: it is the total exemption available in the year of death, minus any taxable gifts the deceased spouse made during their lifetime and any portion of the exemption used to cover assets passing to non-spouse beneficiaries (like children or a trust).

For many families, the DSUE represents millions of dollars in potential tax savings. For example, if a spouse passes away in 2026, when we expect to see the Federal Estate Tax Exemption 2026 ($15 Million), the DSUE could be a substantial sum. If that spouse leaves their entire estate to the survivor, the DSUE is the full $15 million. If the survivor then passes away years later when their own estate has grown to $25 million, they can use their own exemption plus that $15 million DSUE to pay zero federal estate tax.

The catch—and there is always a catch—is that the DSUE is not automatic. You must file Form 706: The Estate Tax Return Explained to claim it. Many grieving spouses skip this step because the estate is under the filing threshold, only to realize years later that they lost a multi-million dollar tax shield that their heirs will now pay for. This highlights the importance of working with professionals who understand that "no tax due now" doesn't mean "no filing required."

The Federal Landscape: How the IRS Handles Portability

The federal government’s approach to portability is designed to be taxpayer-friendly, but it is strictly procedural. The IRS isn't going to call you and remind you to claim your late husband's or wife's exemption. It is a "use it or lose it" election. For veteran estate planners, this is one of the most common points of failure in an estate plan. It’s not that the law is mean-spirited; it’s just that the bureaucracy requires a paper trail.

When we look at the federal landscape, we also have to consider the shifting sands of legislation. Tax laws are rarely permanent. The basic exclusion amount is $15,000,000 for 2026 and is scheduled to be adjusted annually for inflation starting in 2027. Future legislation could still change the exemptions we enjoy today. Understanding how portability interacts with these changes is vital for anyone who considers themselves even moderately wealthy. It’s about more than just current numbers; it’s about locking in today’s high exemptions for the future.

Furthermore, the federal government allows portability for the estate tax, but interestingly, it does not allow portability for the Generation-Skipping Transfer (GST) tax. This is a nuance that often catches people off guard. While you can port your spouse's basic exemption, you cannot port their GST exemption. This is a primary reason why many wealthy families still use Bypass Trust (Credit Shelter) Explained rather than relying solely on portability.

Filing Form 706 for Portability

To secure portability, the executor of the estate must file a federal estate tax return (Form 706) within nine months of the date of death, though a six-month extension is commonly granted. Even if the estate is nowhere near the multi-million dollar threshold for paying taxes, the return must be filed to "elect" portability. This can be a frustrating and expensive process during a time of grief, as Form 706 is a complex document that usually requires a CPA or an estate attorney to complete.

The IRS has recognized how many people miss this deadline and has recently provided some relief. Revenue Procedure 2022-32 now allows certain estates to elect portability up to five years after the date of death, provided the estate wasn't otherwise required to file a return. This is a huge win for surviving spouses who didn't know about portability at the time of their partner's passing. However, you shouldn't rely on this "grace period" as a primary strategy; filing promptly is always the safest bet.

When filling out these forms, precision is key. You are documenting the value of all assets at the time of death, which also helps establish a "stepped-up basis" for capital gains purposes. Using SmartAsset can help you organize your financial picture, but the actual tax filing is where you want an expert in your corner. Missing a single checkbox on Form 706 can lead to the permanent loss of the DSUE, which could cost your children millions in the long run.

The Impact of the 2026 Sunset

We are currently living in a "golden age" of high estate tax exemptions, but the clock is ticking. At the end of 2025, the current laws are set to "sunset," meaning they will revert to pre-2018 levels, adjusted for inflation. This will likely cut the exemption in half. If a spouse dies before the sunset, electing portability allows the survivor to "lock in" that higher current exemption level. This is a critical strategy for the next few years.

If you don't elect portability now and your spouse passes away, and the basic exclusion amount is $15,000,000 for 2026, you can protect the unused exclusion. By filing the Form 706 now, you essentially bank the $15,000,000 (or whatever the current amount is) for your future use. Even if the law changes, the IRS has issued "anti-clawback" regulations that generally protect people who made gifts or locked in exemptions under the higher limits.

This creates a sense of urgency. For couples with estates in the $5 million to $15 million range, the 2026 sunset is a looming cliff. Planning for How State Estate Tax Works alongside these federal changes is the only way to ensure you aren't hit from both sides. It’s a lot to manage, but being proactive now prevents a massive headache (and heartache) for your heirs later.

The Harsh Reality: Why Most States Reject Portability

This is where the conversation takes a turn for the frustrating. You might have a perfect federal plan, but if you live in one of the 12 states (plus the District of Columbia) that have their own estate tax, you are likely in for a surprise. Most of these states—including New York, Massachusetts, Oregon, and Washington—do not allow portability. This means that if you don't use your state-level exemption when the first spouse dies, it is gone forever.

Why are states so "stingy" compared to the federal government? It mostly comes down to two things: money and administrative complexity. States rely heavily on estate tax revenue to fund everything from infrastructure to schools. If they allowed portability, they would essentially be doubling the amount of money that can leave the state tax-free, which would leave a giant hole in their budgets. Unlike the federal government, which can run a deficit, most states are required by law to balance their budgets every year.

Additionally, state tax departments are often smaller and less equipped to handle the long-term tracking required for portability. Federal portability requires the IRS to keep records for decades (until the second spouse dies). Many state tax agencies simply don't have the systems in place to track an "unused state exemption" from 2024 all the way to 2044. For the state, a "use it or lose it" rule is much easier to manage.

Revenue Generation and State Budgets

Estate taxes are often referred to as "voluntary taxes" by planners because, with enough planning, they can often be avoided. However, many people fail to plan, and the states count on that. In states like Oregon or Massachusetts, where the exemption is as low as $1 million or $2 million, it is incredibly easy for a middle-class family with a home and a retirement account to exceed the limit. By denying portability, the state ensures that it gets a "second bite at the apple" when the surviving spouse dies.

Consider a couple in Massachusetts with a $4 million estate. Massachusetts has a $2 million exemption and no portability. If the first spouse dies and leaves everything to the survivor, they haven't used their $2 million exemption. When the second spouse dies with the full $4 million, only $2 million is exempt. The other $2 million is taxed. If portability existed, the full $4 million would have been protected. That "missing" portability translates directly into revenue for the state.

This lack of portability is a significant factor in why some retirees choose to move. We often see people researching States With No Estate Tax (2027) because they realize that staying in their home state will cost their children hundreds of thousands of dollars. It’s a sad reality that tax policy often drives families apart geographically, but until states find a way to replace that revenue, portability is unlikely to become a widespread state-level feature.

Decoupling from Federal Rules

The term "decoupling" is vital to understand here. Years ago, most state estate taxes were linked directly to the federal tax return. If the federal government changed its rules, the state rules changed automatically. However, over the last two decades, many states have "decoupled." They created their own independent tax codes with their own exemptions and their own rules regarding portability.

This decoupling allows states to be more aggressive. For example, while the federal government might raise its exemption to $15 million, a state can choose to keep its exemption at $1 million. They can also choose to ignore federal features like portability or the "stepped-up basis" in some specific scenarios. This independence makes state-level planning much more difficult because you are essentially playing two different games with two different sets of rules at the same time.

When a state decouples, they are basically saying, "We don't care what the IRS does; we need to protect our tax base." This is why a strategy that works for your federal taxes might actually trigger a state tax bill. It requires a delicate balancing act, often involving How to Avoid State Estate Tax Legally through the use of specific state-only trusts that "capture" the first spouse's exemption without triggering a federal filing.

State-Specific Breakdown: Who Offers Portability?

As of 2026, the list of states that offer estate tax portability is incredibly short. In fact, it's essentially a list of two: Maryland and Hawaii. These states are the outliers that have decided to modernize their tax codes to align more closely with federal standards. For residents of these states, estate planning is significantly simpler and more flexible. But for everyone else, the absence of this feature remains a major planning hurdle.

It’s worth noting that even in these "friendly" states, there are often specific requirements that differ from the federal process. You can't just assume that filing the federal Form 706 automatically covers your state portability. You often have to file a state-specific return as well. If you live in a state not on this list, you must assume portability is not available and plan accordingly.

State	Offers Portability?	Notes
Maryland	Yes	First state to adopt it; very taxpayer-friendly.
Hawaii	Yes	Adopted to simplify planning for high-net-worth residents.
New York	No	Features a "cliff" that makes the lack of portability even more painful.
Massachusetts	No	Low exemption makes the lack of portability a common issue.
Oregon	No	One of the lowest exemptions in the country ($1M).
Washington	No	High rates and no portability require complex trust planning.
Connecticut	No	Matches federal exemption but still lacks portability.

Maryland: The Rare Exception

Maryland was a pioneer in state-level portability. They recognized that their residents were being unfairly penalized by the "use it or lose it" nature of the state exemption. In Maryland, a surviving spouse can claim the unused portion of their deceased spouse's state estate tax exemption. This makes Maryland Estate Tax (Plus Inheritance Tax) a unique animal in the world of tax law.

However, even in Maryland, you have to be careful. Maryland also has an inheritance tax, which is different from an estate tax. While the estate tax has portability, the inheritance tax depends on who is receiving the money. It’s a great example of how even a "simple" state can have layers of complexity that require a veteran's eye to navigate.

If you are a Maryland resident, you still need to file a state estate tax return to elect portability, even if no tax is due. Many people make the mistake of thinking portability is "automatic" because they are married. It is never automatic. You must ask for it on the proper forms within the allowed timeframe. If you miss that window, even in Maryland, that exemption is gone.

Hawaii and the Progressive Approach

Hawaii joined the portability club to stay competitive and provide relief to its residents. Hawaii has a relatively high estate tax rate, so the ability to double the exemption through portability is a huge financial benefit for local families. Hawaii Estate Tax (20% Over $10M) is a major concern for those with high-value real estate on the islands, and portability is the primary tool used to mitigate that hit.

Hawaii’s rules generally follow the federal guidelines, meaning that if you are eligible for federal portability, you are likely eligible for Hawaii portability as well. This alignment reduces the administrative burden on families during an already difficult time. It allows for a more unified planning strategy where the federal and state plans work in harmony rather than in conflict.

For residents of other states, Hawaii and Maryland serve as models for what tax reform could look like. However, until other state legislatures see a political or budgetary reason to change, they will likely stick with the current system. For now, if you don't live in these two states, you have to look at other tools, like credit shelter trusts, to achieve the same goal.

The Risks of Doing Nothing: Losing Your Exemption

The biggest risk in estate planning is inertia. Many couples think, "We'll just leave everything to each other and handle the rest later." This "I love you" will is sweet, but it is a tax disaster in states without portability. By leaving everything directly to a spouse, the first spouse to die uses $0 of their state exemption. Because that exemption isn't "portable" in most states, it simply expires.

When the surviving spouse eventually dies, they only have their own single exemption to protect the entire combined estate. If the estate has grown in the meantime, the tax bill can be staggering. We call this the "widow's tax" or the "survivor's penalty." It’s a purely technical tax that could have been avoided with a few extra pages in a trust document.

Furthermore, doing nothing also risks losing the "step-up in basis" on certain assets if they aren't documented properly. While this is more of an income tax issue, it ties into the overall estate settlement. Using SmartAsset to track your total asset value is a good starting point, but you need to translate those numbers into a legal structure that protects them from the "use it or lose it" trap.

The Use-It-or-Lose-It Scenario

Let's look at a real-world example in a state like Washington. Imagine a couple with a $4 million estate. Washington's exemption is roughly $2.19 million. If Spouse A dies and leaves everything to Spouse B, Spouse A's $2.19 million exemption is wasted. Now Spouse B has $4 million. When Spouse B dies, they only have their own $2.19 million exemption. The remaining $1.81 million is taxed at rates up to 20%.

That is a tax bill of several hundred thousand dollars that was completely unnecessary. If Spouse A had instead put $2 million into a trust for the benefit of Spouse B, that $2 million would have "used" Spouse A's exemption. It would then be excluded from Spouse B's estate later. Between the two of them, the full $4 million would have passed to their children tax-free.

This is the heart of why How State Estate Tax Works is so frustrating for families. It’s not about how much money you have; it’s about how that money is titled when the first death occurs. The state doesn't care that you were married for 50 years; they only care about whose name was on the deed and whether an exemption was claimed at the right moment.

Secondary Impacts on Heirs

The loss of an exemption doesn't just hurt the surviving spouse; it directly reduces the inheritance of the children and grandchildren. In many cases, the tax bill is so large that heirs are forced to sell the family home or a family business just to pay the state. This is especially common in states with high property values but low estate tax exemptions.

When an estate is taxed at the state level, the money has to come from somewhere. Usually, it's taken from the liquid assets first (savings, stocks), but if those aren't enough, the executor has to start liquidating real estate. This can lead to family infighting and a lot of resentment toward the "system." It’s a preventable tragedy.

By planning for the lack of portability, you are essentially giving your children a gift of hundreds of thousands of dollars. It’s about ensuring that the wealth you built stays within your family rather than going to the state treasury. It requires a bit of complexity today to ensure simplicity and wealth preservation for the next generation.

Strategies to Bypass the Lack of State Portability

Since most of us don't live in Maryland or Hawaii, we need workarounds. The most common and effective strategy is the use of trusts. Specifically, the "Credit Shelter Trust" (also known as a Bypass or AB Trust) was the standard for decades before federal portability existed, and it remains the gold standard for state-level planning today.

These trusts work by "splitting" the estate upon the first death. Instead of everything going to the survivor, an amount equal to the state exemption is moved into a trust. The survivor can still use the money and get income from it, but technically, they don't "own" it for estate tax purposes. When the survivor dies, the money in the trust passes to the heirs without being counted as part of the survivor's estate.

Another strategy involves lifetime gifting. If you live in a state with an estate tax but no gift tax (which is most states), you can give away money while you are alive to reduce the size of your estate below the exemption limit. However, you have to be careful with the timing and the type of assets you gift, as this can affect capital gains taxes later.

The Credit Shelter or Bypass Trust

The Bypass Trust (Credit Shelter) Explained is the most powerful tool in your arsenal. It essentially creates an "artificial portability." By putting the first spouse's exemption amount into a trust, you ensure that the exemption is "used" immediately. This trust is like a protective bubble; the assets inside can grow to any value, and they will never be taxed again when the second spouse passes away.

For example, if you put a $1 million house into a bypass trust in Oregon, and 20 years later that house is worth $3 million, the entire $3 million passes to your kids tax-free. If you had just left the house to your spouse, that $2 million in growth (plus the original million) would all be sitting in the survivor's estate, likely triggering a massive tax bill.

Setting up these trusts does require an attorney and some administrative work (like filing a separate tax return for the trust each year), but the ROI is usually massive. For a few thousand dollars in legal fees, you can save your family $200,000 or more in state taxes. It’s the ultimate "veteran" move in the world of estate planning.

Lifetime Gifting Strategies

If the idea of a complex trust feels overwhelming, you might consider "gifting out" of the tax. Most states do not tax gifts made during your lifetime. If you are over the state exemption but under the federal one, you can simply give assets to your children or a trust while you are still healthy. This reduces your taxable estate and ensures the state can't touch that money later.

However, you should always check Which States Have a Gift Tax before doing this. Connecticut, for example, is famous for having its own state-level gift tax. For most other states, though, you are free to give. The downside to gifting is that the recipient does not get a "stepped-up basis." If you give your son a stock that you bought for $10 and is now worth $100, his "basis" is $10. If he sells it, he pays capital gains on $90. If he inherits it after you die, his basis "steps up" to $100, and he pays $0 in capital gains.

This is why we often suggest gifting cash or assets that haven't appreciated much, while holding onto highly appreciated assets (like your home) until death. It’s a game of "pick your poison": do you want to pay state estate tax or federal capital gains tax? Using tools like SmartAsset can help you run the numbers on which option is cheaper for your specific family situation.

Disclaimer Trusts

For couples who want flexibility, a "Disclaimer Trust" is a great middle ground. This is a provision in a will that says, "Everything goes to my spouse, but if my spouse decides they don't want part of it, that part goes into a protective trust." This allows the surviving spouse to look at the tax laws at the time of the first death and decide if they need to "use" the exemption.

This is a "wait and see" strategy. If the state legislature suddenly passes a portability law, the spouse can just take the money directly. If the laws are still restrictive, the spouse can "disclaim" the exemption amount, sending it into the trust and saving the taxes. It’s a very popular option because it doesn't force you into a complex trust structure unless it is actually necessary when the time comes.

The only downside to a disclaimer trust is that it requires the surviving spouse to be proactive during a time of extreme grief. They have exactly nine months to make the decision and file the paperwork. If they miss the deadline, the option is gone. For some, the automation of a standard bypass trust is preferable because it doesn't require any "deciding" during a crisis.

Calculating Your Potential Liability

Before you panic about portability, you need to know where you stand. Calculating your potential state estate tax liability involves more than just looking at your bank balance. You have to include the value of your home, your life insurance policies (yes, these usually count toward the estate tax!), your retirement accounts, and even your personal belongings.

Many people are surprised to find that they are "accidental millionaires." If you bought a home in a place like Seattle, Boston, or New York City 30 years ago, that asset alone might put you over the state exemption. When you add in a 401(k) and a life insurance policy from work, you are suddenly in the crosshairs of the state tax collector.

A good rule of thumb is to take your total net worth and subtract your state's exemption. Then, multiply the remainder by 10% to 16% (the average state tax rates). That is the "check" your children will have to write to the state if you don't plan for the lack of portability. Seeing that number in black and white is usually all the motivation people need to get their planning in order.

Do I Need to File Even if No Tax is Due?

At the federal level, the answer is a resounding "Yes" if you want portability. At the state level, the answer is "It depends." In states without portability, you generally only file a return if the estate exceeds the exemption and tax is actually owed. However, some states require a "pro forma" return or an affidavit to clear the title on real estate.

In states with portability, like Maryland, you must file a return to elect the portability, even if the estate is $0. This is the most common trap for residents of those states. They think, "Well, there's no tax, so why would I file a return?" But the return is the election. No return, no portability.

Always check the local rules for State Estate Tax Returns: Forms & Deadlines. Missing a filing deadline can be an expensive mistake. Even if you think you are safe, it is worth paying a professional for an hour of their time to confirm that you aren't leaving a mess for your heirs to clean up later.

Professional Guidance and Tools

Estate planning is not a DIY project. While there are great online tools to help you get organized, the intersection of federal and state tax law is too complex for most people to handle alone. A veteran estate planning attorney who knows your specific state's quirks is worth their weight in gold. They can help you navigate the nuances of How to Avoid State Estate Tax Legally and ensure your trusts are drafted correctly.

In addition to legal help, financial tools like SmartAsset can provide a clear picture of your asset growth over time. If you are 60 years old and have $2 million, you might think you are safe. But if that money grows at 7% for the next 20 years, your estate will be worth over $7 million. You need to plan for the estate you will have, not just the estate you have today.

Ultimately, portability is a great federal benefit that we should all take advantage of, but we cannot let it blind us to the realities of state-level taxes. By understanding why most states don't offer it, you can take the necessary steps—like setting up a bypass trust or starting a gifting program—to ensure your legacy is protected. Don't let a technicality in the tax code be the reason your hard work ends up in the state's coffers.

State Estate Tax Disclaimer

This guide is for informational purposes only and does not constitute legal, financial, or tax advice. Estate tax laws, exemptions, and portability rules are subject to frequent legislative changes at both the federal and state levels. Readers should consult with a qualified estate planning attorney or tax professional licensed in their specific state to develop a plan tailored to their unique circumstances. No attorney-client relationship is formed by the use of this guide.