An $850K Tax Bill, $200K in Cash: The $650K Estate Liquidity Gap
Federal estate tax is due in cash within 9 months of death. A $3M family business plus $200K in liquid savings against an $850K total cash need leaves a $650K gap — and heirs without a plan end up selling the business under time pressure to close it.
Wealthy on paper, cash-poor at the worst possible time
We ran a common family-business scenario through the calculator: an $800,000 estate tax bill, $50,000 in other settlement costs, $200,000 in liquid assets on hand, and a $3,000,000 business as the bulk of the estate's actual value. The total cash needed — $850,000 — outstrips the $200,000 in liquid assets by $650,000. That gap doesn't go away because the business itself is worth far more than the tax bill; federal estate tax is due in cash within 9 months of death, and a business isn't cash.
Families in this position often end up selling the business — or a stake in it — under real time pressure, frequently to whichever buyer can close fastest rather than whoever offers the best price. The gap this tool surfaces is exactly the number life insurance (ideally held in an ILIT) is designed to solve, sized precisely so the family never has to choose between paying the IRS and keeping the business.
How the math works
Total cash needed = estate tax owed + other settlement costs. Liquidity gap = max(0, total cash needed − liquid assets available). Percent of illiquid assets at risk = liquidity gap ÷ illiquid asset value, clamped between 0% and 100% — a rough proxy, not a prediction of exactly what would be sold.
Source: IRC §6151 (estate tax generally due within 9 months of death); IRC §6166 (installment-payment relief for a qualifying closely-held business interest — a real option this tool doesn't model, worth exploring with an estate attorney if it applies).
Math runs locally. Inputs never leave your browser.Source on github.
Where this calculation doesn't apply
- The estate qualifies for IRC §6166 installment payment.A closely-held business making up more than 35% of the adjusted gross estate can qualify to pay estate tax attributable to it over up to 14 years — a real alternative to a forced sale this tool doesn't model.
- There's no illiquid asset at all.If the estate is entirely liquid (cash, marketable securities), there's no forced-sale risk regardless of the gap — the percent-at-risk figure is 0% by construction in that case.
- A state extension or different filing timeline applies.State-level estate/inheritance tax deadlines and extension rules vary and aren't modeled here — check your specific state's requirements.
- Heirs are willing and able to sell at market pace, not under duress.If there's flexibility on timing (an extension, sufficient liquid reserves elsewhere), the "forced sale at a discount" risk this tool implicitly flags may not apply.
What to actually do
- Run the Estate Tax Exposure tool first to get a realistic estate tax figure for this calculation.
- Total up genuinely liquid assets honestly — don't count illiquid holdings or assets that would themselves take months to sell.
- If a meaningful gap exists, price out life insurance sized to cover it — ideally structured through an ILIT so the proceeds don't add to the taxable estate.
- Ask an estate attorney whether the illiquid asset (if a closely-held business) might qualify for IRC §6166 installment payment relief.
- Revisit the numbers periodically — both the estate tax exposure and the liquid/illiquid asset mix change over time.