What Is an Estate Tax Return, and Why Does It Cost So Much?

When my dad died, I expected paperwork: banks, attorneys, account transfers, property records, forms I had never heard of.

What I did not expect was to be told his estate might need a tax return costing roughly $10,000 to prepare, even though it did not owe federal estate tax.

That raised a few reasonable questions:

• What exactly is an estate tax return?

• Why file one if no tax is due?

• Why does it cost thousands of dollars?

• Can you do this through TurboTax?

• How do you know whether you actually need one?

People use "estate tax return" to describe a specific federal filing: IRS Form 706, United States Estate (and Generation-Skipping Transfer) Tax Return. Here is the practical version, starting with the question that matters most: do you actually have to file one?

Who Has to File, and Who Should Just Consider It

For a U.S. citizen or resident who dies in 2026, Form 706 is legally required when the gross estate, plus certain taxable lifetime gifts, exceeds $15 million. For deaths in 2025, the threshold was $13.99 million. The threshold follows the law in effect the year the person died, not the year the return is prepared.

"Gross estate" is broader than most people expect. It can include:

• Houses and other real estate

• Bank and brokerage accounts

• Retirement accounts

• Business interests

• Life insurance proceeds, when included under estate-tax rules

• Annuities

• Trust assets over which the person retained certain rights

• Personal property, including jewelry, art, vehicles, and collections

• The deceased person's share of jointly owned property

The gross estate is calculated before subtracting mortgages, debts, administration expenses, charitable gifts, or the marital deduction. So a person does not need $15 million in the bank to have a $15 million gross estate.

Still, most estates fall well below the federal threshold and are not required to file.

That is not the end of the story. Even a modest estate might want to file anyway, for a reason most families have never heard of: portability. In short, filing Form 706 can let a surviving spouse preserve their late spouse's unused exemption for later, potentially worth millions down the road. That is often the real reason a family with no tax due still gets a bill for thousands of dollars in preparation work. More on exactly how that works below.

What Are The Different Tax Returns After Someone Dies?

Before going further, it helps to separate three filings that are often confused with one another.

1. The deceased person's final income tax return

This is the final Form 1040, covering income received from January 1 through the date of death. It looks like an ordinary personal return, though the executor or personal representative signs it.

2. The estate's income tax return

After death, the estate may become its own taxpaying entity. If it receives income, such as interest, dividends, rent, or investment gains, it may need to file Form 1041, U.S. Income Tax Return for Estates and Trusts. An estate generally must file Form 1041 once it has at least $600 of gross income during the tax year, though other rules can also trigger filing.

3. The federal estate tax return

This is Form 706: an accounting of the person's property, certain lifetime gifts, debts, expenses, deductions, and tax calculations. The IRS describes the estate tax as a tax on the right to transfer property at death. Assets are generally reported at fair market value as of the date of death, not necessarily what the person originally paid.

Form 706 is the return people mean when they say an estate tax return costs several thousand dollars, and the one this guide focuses on.

Why Would an Estate Below the Threshold File Anyway?

The most common reason is portability, which lets a surviving spouse preserve the deceased spouse's unused federal estate and gift tax exemption. The preserved amount is called the deceased spousal unused exclusion, or DSUE.

Say one spouse dies in 2026 with a $7 million estate and no significant lifetime gifts. That estate is below the $15 million filing threshold, so Form 706 is not legally required based on size alone. But roughly $8 million of that person's exemption goes unused. By filing Form 706 and electing portability, the executor can preserve that unused exemption for the surviving spouse.

This can matter later if the surviving spouse:

• Lives many more years while assets appreciate

• Owns valuable real estate

• Receives an inheritance

• Sells a business

• Makes substantial lifetime gifts

• Remarries

• Eventually has an estate large enough to face federal estate tax

The portability election is made by filing a timely, complete Form 706. That means an estate may spend thousands of dollars on a return that shows zero tax due, because the real purpose is preserving a future benefit for the surviving spouse.

A Practical Portability Example

Suppose a married couple has a combined net worth of $18 million in 2026. The husband dies first with $7 million in his estate. Everything passes to his wife, so the marital deduction may prevent estate tax at his death. Without portability, his unused exemption disappears.

If the estate files Form 706 and elects portability, that unused exemption becomes available to his wife, in addition to her own. Combined, that could save the family millions in estate tax.

It could also never matter. The surviving spouse may spend down the assets. Property values may fall. Tax laws may change. She may leave everything to charity. The final estate may stay below the exemption.

Portability is partly an insurance decision: is the cost of filing now justified by the chance the surviving spouse needs the extra exemption later?

Does Portability Mean a Married Couple Automatically Gets Two Exemptions?

No. The unused exemption is not transferred automatically just because the couple was married. The executor must file Form 706 and make the election.

There is also a remarriage wrinkle: a surviving spouse can generally use only the DSUE amount of their most recent deceased spouse. A later marriage and death can change which DSUE amount is available, which is one reason portability planning belongs with an estate-planning professional rather than treated as clerical.

Portability also does not cover every estate-planning benefit. The generation-skipping transfer tax exemption, in particular, is not portable the same way.

When Is Form 706 Due?

Generally, nine months after the date of death. An automatic six-month extension to file is available by timely filing Form 4768, pushing the deadline to 15 months after death. But an extension to file does not extend the deadline to pay any tax due.

Nine months can arrive quickly. During that window, the family may also be planning a funeral, locating estate documents, applying for an employer identification number, notifying banks, handling probate or trust administration, selling or maintaining property, obtaining death certificates, retitling accounts, finding appraisers, and dealing with grief.

If portability might be worthwhile, raise the question early rather than discovering the deadline in month eight.

What Happens If the Portability Deadline Was Missed?

Not necessarily lost forever. For an estate that was not otherwise required to file because it was below the threshold, IRS Revenue Procedure 2022-32 offers a simplified method for a late portability election. A qualifying estate can generally file a complete Form 706 by the fifth anniversary of death, with a notation that it is filed under Revenue Procedure 2022-32 to elect portability.

That relief does not apply if the estate had a mandatory filing requirement and simply failed to file. A missed deadline may be fixable, but it should not be ignored.

Why Is an Estate Tax Return So Expensive?

Form 706 looks like another tax form. It is not. It is closer to a financial reconstruction of the person's life as of one exact date.

The preparer must identify, document, classify, and value every reportable interest the person owned, and determine which debts, expenses, deductions, transfers, and prior gifts affect the calculation.

The work is in the schedules and supporting documentation

A Form 706 package can include schedules for real estate, stocks and bonds, mortgages and notes, cash, life insurance, jointly owned property, miscellaneous property, transfers made during life, powers of appointment, annuities, funeral and administration expenses, debts and mortgages, charitable transfers, property passing to a surviving spouse, generation-skipping transfers, and prior taxable gifts.

Once appraisals, account statements, trust documents, insurance forms, and supplemental schedules are attached, the return can run hundreds of pages.

Asset valuation carries real responsibility

Publicly traded investments are relatively straightforward, though even those need date-of-death pricing. Real estate, private businesses, partnerships, and unusual personal property may require qualified appraisals. The IRS expects fair market value, not a Zillow estimate, an old property-tax value, or a financial-statement figure.

Valuation mistakes can affect whether the estate was required to file, the amount of tax owed, the surviving spouse's DSUE amount, the income-tax basis of inherited property, later capital-gains calculations, and information reported to beneficiaries. The Form 706 instructions also include penalties for substantial or gross valuation understatements.

The preparer may have to reconstruct prior gifts

The calculation does not stop at property owned at death. The preparer must determine whether the deceased made prior taxable gifts, whether gift-tax returns were filed, and how those gifts affect the estate-tax computation. That can mean tracking down decades-old Form 709 gift-tax returns or reviewing transfers family members barely remember.

Trusts and jointly owned property require legal analysis

Owning an asset in a trust does not automatically keep it outside the taxable estate. The preparer may need to review whether a trust was revocable or irrevocable, which powers the deceased retained, who contributed property to a joint account, whether life insurance is includible, whether property qualifies for the marital deduction, how business entities were owned, and whether lifetime transfers are pulled back into the estate. At that point, the work overlaps accounting, tax law, estate planning, and valuation.

Portability returns still require care

A portability-only return can sometimes use simplified valuation rules for assets passing to a spouse or charity, which may ease the appraisal burden. But "no tax due" does not mean "nothing to calculate." The preparer still needs enough information to establish the gross estate, deductions, exemption used, and DSUE amount, since the IRS can examine the deceased spouse's return later when the surviving spouse tries to use the transferred exemption.

How Much Does Form 706 Preparation Cost?

There is no standard national fee. Published pricing shows basic Form 706 work starting around $2,500, rising with complexity. Some firms advertise lower fees for simple portability-only filings; more involved returns can run many thousands of dollars.

A $10,000 quote is not automatically unreasonable, particularly with several properties, business interests, complicated trusts, prior gifts, or hard-to-value assets involved. But it is also not a price to accept without understanding the scope. Ask whether the quote includes:

• Preparation of Form 706

• Review of trust and estate-planning documents

• Date-of-death valuation work

• Coordination with appraisers

• Review of prior gift-tax returns

• Portability calculations

• Responding to routine IRS correspondence

• Preparing Form 8971 and beneficiary statements, if required

• Obtaining an estate-tax closing letter

• Attorney review

• Audit representation

• Appraisal costs

A $5,000 preparation fee plus $8,000 in appraisal work is very different from a flat $13,000 professional fee.

Can You Prepare Form 706 With TurboTax?

Not through the consumer TurboTax products used for individual income-tax returns. TurboTax is built for returns like Form 1040 and, through certain products, income-tax returns for estates and trusts like Form 1041. Form 706 is a specialized federal transfer-tax return. Intuit's own estate guidance separates the estate's income-tax filing from Form 706 and notes that the personal representative is responsible for filing Form 706 when estate tax applies.

There is no interview where you enter the house, retirement account, and brokerage statement and get a defensible federal estate-tax return out the other end.

Technically, you can download Form 706 and its instructions from the IRS and prepare it yourself. The IRS does not require a CPA or attorney. The better question is not whether you are legally allowed to do this yourself, but whether you understand the estate-tax inclusion, deduction, valuation, gift, and portability rules well enough to sign the return under penalties of perjury.

For a small, straightforward portability filing, a highly organized executor with real tax experience might manage it. For most families, Form 706 is not a good first do-it-yourself tax project.

Do You Need a CPA or an Estate Attorney?

Not every CPA prepares estate-tax returns, and not every estate-planning attorney does either. Look for someone who regularly handles Form 706 and federal estate and gift tax, not simply someone who prepares individual returns or drafts wills.

The right professional might be a CPA specializing in estate and gift taxation, an estate or tax attorney who prepares Form 706, a CPA and attorney working together, or an enrolled agent with meaningful estate-tax experience.

Ask directly:

1. How many Forms 706 do you prepare each year?

2. How many are portability-only returns?

3. What documents will you need from me?

4. Which assets require formal appraisals?

5. Is the fee fixed, hourly, or an estimate?

6. What work is excluded?

7. Who will actually prepare and review the return?

8. Will you handle IRS follow-up?

9. Do you also prepare the estate's Form 1041?

10. Can you explain why filing is recommended in this specific estate?

A professional should be able to explain the reason for filing in plain English. "Because estates file this" is not an adequate answer.

Does Filing Form 706 Mean the Estate Will Pay Estate Tax?

No. Three outcomes are common.

The estate is required to file and owes tax. This generally happens when the taxable estate exceeds the available exemption after deductions, credits, and prior exemption use. Federal estate-tax rates are graduated, topping out at 40 percent.

The estate is required to file but owes no tax. An estate may exceed the gross-estate filing threshold but owe nothing because property passes to a surviving spouse or charity, or other deductions eliminate the taxable amount.

The estate is not required to file but files for portability. This is common when the first spouse dies and the family wants to preserve the unused exemption for the survivor.

The existence of a Form 706 does not, by itself, mean a check is going to the IRS.

How Do You Decide Whether a Portability Return Is Worth the Cost?

This is ultimately a planning decision, but these questions help: What is the surviving spouse's current net worth? How much unused exemption could be preserved? How old is the surviving spouse? How quickly are the assets likely to appreciate? Does the surviving spouse own real estate, a business, or concentrated investments? Is another inheritance likely? Does the surviving spouse plan to make large gifts? Could future estate-tax law become less generous? How complex and expensive would the return be? Would filing also establish useful date-of-death valuations and records?

For a surviving spouse with a modest estate and little chance of substantial growth, spending $10,000 on portability may be hard to justify. For a surviving spouse with valuable real estate, a long life expectancy, and a combined estate approaching the exemption, skipping the filing could be an expensive gamble.

The goal is an informed decision, not a reflexive filing and not a dismissal just because no tax is due today.

The Bottom Line

A federal estate tax return is not the deceased person's final income-tax return, and it is not the estate's annual income-tax return. It is a specialized accounting of the person's assets, liabilities, deductions, prior gifts, and estate-tax position.

Most estates are not large enough to be required to file Form 706. But some file anyway to preserve a deceased spouse's unused exemption through portability, which is why a family can owe no estate tax and still get a quote for thousands of dollars in preparation work.

Before agreeing to the expense, get clear answers to four questions:

1. Is the estate legally required to file?

2. If not, is the sole purpose portability?

3. How much unused exemption would actually be preserved?

4. What facts make that preserved exemption likely to matter?

Form 706 can be valuable. It can also be expensive, tedious, and unnecessary. You deserve to know which one it is before writing the check.