不用缴税的遗产总额应是$10.86m, 如果你们遗产超过千万，那俺也帮不了你了。
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参考资料：
Setting up a marital living trust lets you and your spouse pass your assets tax-free to your beneficiaries. Husband and wife living trusts use the marital deduction and unified credit to reduce or eliminate asset transfer taxes. With the marital deduction, you can give all of your assets to your surviving spouse tax-free. When your surviving spouse dies, the unified credit offsets the tax so your beneficiaries have no tax liability. At the time of publication（2014）, the unified credit amount for each spouse is $5.340 million.
http://budgeting.thenest.com/husband-wife-living-trusts-34256.html
For 2009 tax returns, every American received an automatic unified tax credit against federal estate and gift taxes of $1,455,800, which is equivalent to transferring $3.5 million tax-free to your heirs. If you were married, your spouse (also a U.S. citizen) received the same exemption credit, so that you could, as a couple, give a full $7 million to your heirs free of estate tax. There was no estate tax on the first $3.5 million in 2009, meaning you were not required to pay taxes until the sum reached over $3.5 million in 2009.
http://law.freeadvice.com/tax_law/estate_tax_law/unified_tax_credit.htm
