IRS published Rev. Proc. 2015-53 providing inflation-adjusted items for 2016. The following adjustments affect Federal estate tax:

.33 Unified Credit Against Estate Tax. For an estate of any decedent dying in calendar year 2016, the basic exclusion amount is $5,450,000 for determining the amount of the unified credit against estate tax under § 2010.

.34 Valuation of Qualified Real Property in Decedent's Gross Estate. For an estate of a decedent dying in calendar year 2016, if the executor elects to use the special use valuation method under § 2032A for qualified real property, the aggregate decrease in the value of qualified real property resulting from electing to use § 2032A for purposes of the estate tax cannot exceed $1,110,000.

.35 Annual Exclusion for Gifts.  

(1) For calendar year 2016, the first $14,000 of gifts to any person (other than gifts of future interests in property) are not included in the total amount of taxable gifts under § 2503 made during that year.
(2) For calendar year 2016, the first $148,000 of gifts to a spouse who is not a citizen of the United States (other than gifts of future interests in property) are not included in the total amount of taxable gifts under §§ 2503 and 2523(i)(2) made during that year. 

.42 Interest on a Certain Portion of the Estate Tax Payable in Installments.  For an estate of a decedent dying in calendar year 2016, the dollar amount used to determine the "2-percent portion" (for purposes of calculating interest under § 6601(j)) of the estate tax extended as provided in § 6166 is $1,480,000.

We will be updating our table for calculating the 2% portion of tax deferred under section § 6166.

There is also an adjustment to the § 6651(a)(1) failure to file penalty:

.43 Failure to File Tax Return.  For tax years beginning in 2016, the amount of the additional tax under § 6651(a) for failure to file a tax return within 60 days of the due date of such return (determined with regard to any extensions of time for filing) shall not be less than the lesser of $135 or 100 percent of the amount required to shown as tax on such returns.