When real property is part of a taxable estate, the IRS does not simply accept whatever value is most convenient for the estate. Federal law imposes specific requirements for how real estate must be valued, who can perform that valuation, and what the resulting appraisal must contain. An estate that gets this wrong — even innocently — can face penalties, deficiency assessments, or a disputed valuation that adds significant time and cost to settlement.
This article explains the IRS framework for real estate valuation in estate tax contexts, what a "qualified appraisal" actually means under Treasury regulations, and what executors, estate attorneys, and accountants need to know to avoid common pitfalls.
The Federal Estate Tax Threshold and When Real Estate Valuation Is Required
The federal estate tax applies to estates above the applicable exclusion amount. As of 2026, the federal exemption is approximately $13.6 million per individual (indexed for inflation), meaning estates below that threshold generally do not owe federal estate tax. However, even estates below the federal threshold may need real estate appraisals for other purposes: New York State has its own estate tax with a much lower threshold (currently approximately $7.16 million), and all estates need accurate valuations to establish the stepped-up cost basis inherited beneficiaries will use for capital gains purposes.
The stepped-up basis issue is critical and often underappreciated. When a beneficiary inherits property, their cost basis is reset to the fair market value on the date of the decedent's death — not the original purchase price. This can save significant capital gains tax when the property is eventually sold. But that stepped-up basis must be supportable if the IRS later scrutinizes a sale. A credible appraisal as of the date of death is the foundation of that defense.
The IRS Standard: Fair Market Value as of the Date of Death
The IRS defines the value of estate property as its fair market value as of the date of the decedent's death (or an alternate valuation date in limited circumstances). The IRS defines fair market value as:
"The price at which the property would change hands between a willing buyer and a willing seller, neither being under any compulsion to buy or to sell, and both having reasonable knowledge of relevant facts."
This is the same standard used in all certified appraisals — but the application has some nuances specific to the estate context.
The Alternate Valuation Date
Under IRC Section 2032, an executor may elect to value estate assets at the alternate valuation date — six months after the date of death — if doing so would reduce both the gross estate value and the estate tax liability. This election applies to all estate assets, not just real estate. If property was sold or distributed within the six-month period, it is valued as of the disposition date rather than the alternate date.
The alternate valuation election is not available for estates that do not owe federal estate tax. It requires the executor to make the election on a timely-filed Form 706.
What Qualifies as an Acceptable Appraisal for IRS Purposes
Treasury Regulation § 20.2031-1(b) and related guidance establish the requirements for valuing real property for estate tax. For real estate included in a taxable estate (or any estate filing Form 706), the IRS expects a qualified appraisal performed by a qualified appraiser — terms with specific legal definitions.
Qualified Appraiser Requirements
Under Treasury Regulation § 1.170A-17 (applicable by extension to estate and gift tax contexts), a qualified appraiser must:
- Have an appraisal designation from a recognized professional organization, or have otherwise met minimum education and experience requirements for valuing the type of property being appraised
- Regularly perform appraisals for which they are compensated
- Not be a disqualified person — meaning they cannot be the donor, donee, executor, or a party with a financial interest in the transaction
- Not be the taxpayer whose tax liability is being determined
For residential real estate in New York and the tri-state region, this typically means a New York State Certified Residential or Certified General Appraiser with relevant market experience. A broker's opinion of value, a county assessment, or an automated valuation model (AVM) does not satisfy these requirements.
Qualified Appraisal Requirements
The appraisal report itself must meet specific content requirements:
- Description of the property being appraised
- The date of the appraisal and the effective date of value (the date of death or alternate valuation date)
- The purpose of the appraisal and the definition of value being applied (fair market value)
- A description of the method used to determine value — typically the sales comparison approach for residential property
- The specific basis for the value conclusion, including the comparable sales analyzed and the adjustments applied
- The appraiser's qualifications, state license number, and signature
The IRS requires that the appraisal be conducted no earlier than 60 days before the date of the gift or transfer and no later than the due date (including extensions) of the return on which the appraisal is reported. For estate tax, this means the appraisal must be completed before the Form 706 filing deadline — nine months after the date of death, with a possible six-month extension.
The Retrospective Appraisal: Valuing Property as of a Past Date
Estate appraisals are inherently retrospective — the appraiser must determine what a property was worth on a specific date in the past, which may be months or even years before the appraisal is actually performed. This requires the appraiser to use market data (comparable sales, market conditions) from the period surrounding the date of death, not current data.
An appraiser performing a date-of-death valuation must be able to credibly reconstruct the market as it existed at the relevant time. This means:
- Identifying comparable sales that closed within a reasonable window around the date of death
- Applying market condition adjustments based on actual market data from that period
- Avoiding hindsight — not using information that was not publicly available at the valuation date
For estates in active real estate markets like Westchester County, Manhattan, or Greenwich, CT, where values can shift materially within months, the effective date of the appraisal is highly significant. An appraisal as of a date during a market peak will produce a materially different value than one as of a date six months later — and both may be correct for their respective effective dates.
IRS Scrutiny and the Substantial Valuation Misstatement Penalty
The IRS does not passively accept estate tax returns. Returns reporting large real estate values — or large charitable deductions involving real property — are subject to examination. When the IRS disagrees with a reported value, it will conduct its own valuation analysis and may issue a Notice of Deficiency if it concludes the estate undervalued the property.
Beyond the tax deficiency itself, estates face potential accuracy-related penalties under IRC Section 6662:
| Valuation Misstatement Type | Penalty | Threshold |
|---|---|---|
| Substantial valuation misstatement | 20% of underpayment | Reported value is 65% or less of the correct value |
| Gross valuation misstatement | 40% of underpayment | Reported value is 40% or less of the correct value |
The penalties apply to the portion of the tax underpayment attributable to the valuation error. On a significant estate, these can represent substantial additional liability on top of the tax itself.
The best defense against these penalties is a well-documented, credible qualified appraisal prepared by a qualified appraiser. A report that clearly identifies the comparable sales used, explains the adjustments applied, and reaches a defensible conclusion based on market evidence is far more likely to withstand IRS scrutiny than a thin, undocumented estimate.
New York State Estate Tax Considerations
New York State imposes its own estate tax, with an exemption threshold significantly lower than the federal threshold. Estates with New York real property above the state threshold must file a New York State estate tax return (Form ET-706), and real property must be valued using the same fair market value standard.
New York has an unusual "cliff" provision: if the taxable estate exceeds 105% of the basic exemption amount, the exemption is phased out entirely and the entire estate — not just the excess — is subject to tax. This means careful valuation of real estate is particularly important for estates near the New York threshold, where the difference between a slightly lower and slightly higher value can have a large effect on total tax liability.
Fractional Interest Discounts
When a decedent owned a fractional interest in real property — for example, a 50% tenancy-in-common interest shared with another party — the value of that interest for estate tax purposes is typically less than 50% of the whole property's value. This is because a buyer purchasing only a partial interest faces practical limitations: they cannot sell the whole property unilaterally, cannot exclusively occupy it, and may face partition proceedings to realize their investment.
The IRS has historically scrutinized large fractional interest discounts, and the discount must be supportable based on market evidence. An appraiser valuing a fractional interest must be experienced in this methodology and must document the discount with reference to paired sales or other market data.
Practical Guidance for Executors and Attorneys
If you are administering an estate that includes New York real property, here is what the timeline and process should look like:
- Identify all real property in the estate promptly after the date of death. Note the address, ownership structure, and any encumbrances.
- Engage a qualified appraiser with experience in estate work and familiarity with the relevant market. The appraiser should be state-certified and independent of the estate.
- Provide the appraiser with the date of death and any relevant property information: prior appraisals, tax records, permits, renovation history, leases if applicable.
- Ensure the appraisal is completed before the Form 706 filing deadline. Don't wait until the last minute — appraisers with estate experience are often in demand, and producing a retrospective appraisal of high quality takes time.
- Retain the appraisal permanently. Even after the estate is closed and the tax return is filed, the appraisal supports the beneficiaries' stepped-up basis for future capital gains purposes.
Frequently Asked Questions
Can we use the county assessment to value real estate for estate tax?
No. County assessments are not fair market value appraisals, and the IRS does not accept them as substitutes for a qualified appraisal. Assessments often lag market values by years and use mass appraisal methodologies that do not reflect individual property characteristics.
What if the property was sold shortly after the date of death?
A sale shortly after death — particularly an arm's-length sale with no unusual conditions — can be strong evidence of fair market value at the date of death, especially if market conditions were stable. However, the executor should still consult with a qualified appraiser and the estate's attorney before relying solely on the sale price.
Do we need an appraisal if the estate is below the federal exemption?
Not necessarily for federal estate tax purposes, but potentially for New York State estate tax (if the estate is above the NY threshold) and almost certainly for stepped-up basis purposes. Beneficiaries who may sell the property in the future will want a contemporaneous date-of-death appraisal to document their basis. Without it, demonstrating the correct basis to the IRS years later can be difficult.
How far back can a retrospective appraisal go?
There is no hard cutoff, but the further back the effective date, the more challenging it is to produce a credible retrospective appraisal — because historical market data and comparable sales information becomes less complete over time. Appraisers experienced in this type of work can often produce credible retrospective appraisals going back several years if sufficient market data is available.
What happens if the IRS challenges our appraisal?
The IRS will conduct its own valuation analysis and may propose an adjusted value through a Notice of Deficiency. The estate can contest the IRS's proposed value through the IRS appeals process or, if necessary, in Tax Court. The strength of the estate's position depends substantially on the quality and documentation of the original appraisal. A well-prepared qualified appraisal is your first and most important line of defense.