Data Methodology

Data Sources

PlainEstate draws from four primary sources to provide a comprehensive picture of estate taxation and probate costs across the United States:

• IRS Statistics of Income (SOI) - Estate tax return statistics covering returns filed 2017–2024. Published by the IRS Statistics of Income division, this is the definitive source for how many estates actually pay federal estate tax each year, how much they pay, and how estate values are distributed across size brackets. The SOI data provides the only reliable measure of the federal estate tax's actual impact on American families.
• Tax Foundation - State estate and inheritance tax rates, exemption amounts, and rate brackets for all states that impose these taxes. The Tax Foundation is a nonpartisan research organization that collects and annually updates this data from state statutes, revenue department publications, and legislative session records. Their compilations are widely cited by tax professionals and policymakers.
• State Court Fee Schedules - Probate filing fees, court costs, and attorney fee structures from official state court websites, published fee schedules, and court administrative orders for all 50 states plus the District of Columbia. Includes data published by individual state administrative offices of the courts (for example, see Judicial Branch of California probate fee schedules and similar publications from each state). These fees vary significantly by state and by estate value.
• State Statutes - Small estate threshold amounts, simplified probate procedures, and affidavit transfer options sourced from official state code publications such as those published by individual state legislatures. The Administrative Office of the U.S. Courts publishes federal-side probate-adjacent procedural materials. The Uniform Probate Code (UPC) serves as the model statute that many states adopt in whole or in part. These thresholds determine whether a full probate proceeding is required or whether a simplified process is available.

Populations that must not be mixed

PlainEstate renders three separately dated populations. Ratios, Dataset temporalCoverage, CiteThis stamps, and side-by-side totals must never pretend they share one year:

1. National IRS SOI filing years (2017-2024) - aggregate returns, taxable returns, and tax dollars from irs_soi_estate_stats. This is a filing-year stock, not current-law rates.
2. State-level IRS SOI filings (typically 2021-2023 per state) - per-state returns in irs_soi_state_filings. The national table can lead the state table by a year because IRS releases differ; we stamp each series from its own rows.
3. Current-law federal exemption + state statutes (Tax Foundation 2024 survey + court fee schedules) - the live exemption (permanent $15M from 2026) and state rates/fees. These are not SOI filing years.

Homepage and state Dataset schema stamp only the SOI series rendered on that page. CiteThis and trust footers name all three populations. ETL rebuild timestamps are never used as claim years.

Corpus placement (#N of M)

Each state profile shows an analytical corpus rank so a reader can place the state without leaving the page. Ordinals come from this portal's compiled tables only and match the linked rankings listings:

• All surveyed states: ordered by maximum probate filing fee ascending (lowest max fee = #1), same basis as lowest probate filing fees.
• Estate-tax states: ordered by exemption threshold ascending (lowest exemption = #1), same basis as lowest exemptions.
• Estate-tax states (rate): ordered by top marginal rate descending (highest rate = #1), same basis as highest rates.

#1 means extreme on that fee or tax basis for this publication vintage, not a quality grade or legal endorsement. The alphabetical /states hub remains A-Z; analytical placement lives on the detail page and the ranking lists above.

Data Vintage and Update Frequency

IRS SOI estate tax data covers returns filed through 2024, which is the most recent year available, SOI data typically lags by 2 to 3 years because the IRS requires time to compile, verify, and publish tax return statistics. Tax Foundation state tax data is updated annually as states modify their estate and inheritance tax laws during legislative sessions. Probate court fee data is reviewed periodically and updated when states publish new fee schedules through legislation or court administrative rule changes. The 2026 TCJA sunset, which would have reduced the federal estate tax exemption to roughly $7 million per individual, was repealed by the One Big Beautiful Bill Act (Pub. L. 119-21, July 2025), which instead set a permanent $15 million per-individual exemption effective January 1, 2026, indexed for inflation.

Processing Pipeline

1. IRS SOI estate tax tables are extracted from published SOI bulletins and organized by filing year, filing status, and estate size bracket. Aggregate statistics on total estates filed, taxable estates, and tax collected are computed from the underlying tables.
2. Tax Foundation state tax data is normalized to a consistent format, exemption amounts in absolute dollars, marginal rates by bracket, inheritance tax class distinctions (spouse, child, sibling, unrelated), and effective date of current law.
3. Probate data is organized by state: typical attorney fees (flat, percentage-based, or hourly with estimated ranges), executor or personal representative fees, court filing costs, and estimated total probate costs for sample estate sizes at $100,000, $500,000, and $1 million.
4. Small estate thresholds and simplified procedure availability are recorded for each state, including whether the state allows transfer-on-death deeds, payable-on-death accounts, and other probate avoidance mechanisms.
5. State profiles are enriched with contextual data including the number of estate tax returns filed in each state, the percentage of estates that actually owe tax, and comparisons to neighboring states.
6. All data is loaded into a structured SQLite database serving state profiles, comparison pages, federal estate tax summaries, and interactive lookup tools.

Coverage

• Federal estate tax: IRS SOI data 2017–2024, current exemption amounts and rate tables
• State estate tax: 13 states + D.C. that impose a separate estate tax
• Inheritance tax: 6 states that tax heirs directly based on relationship to the decedent
• Probate data: All 50 states + D.C., including filing fees, attorney costs, and simplified procedures
• Small estate thresholds: All 50 states + D.C.

Accuracy Commitment

PlainEstate reproduces source data exactly as published by the IRS, Tax Foundation, and state court systems. Tax rates, exemption amounts, and fee schedules are presented without editorial modification. When state laws change mid-year, PlainEstate updates the affected state profiles as soon as the new rules are confirmed in official publications. All dollar amounts reflect nominal values as published by the source agencies.