The IRS has published the “section 7520” interest rates for the month of November, 2017, in Revenue Ruling 2017-21. The sec. 7520 rate is 2.4%. The section 7520 interest rate is used in a variety of computations for estate and gift tax purposes. Frequently, the difference between the section 7520 rate and an interest rate which more accurately reflects ‘real world’ interest rates (or more typically, projected rates of return on an investment portfolio, or the rate of appreciation of an asset), is the primary factor which allows various types of trusts and transfers to trusts to become tax-favored.