你看一下IRS這篇解釋：https://www.irs.gov/retirement-plans/substantially-equal-periodic-payments
文中例子：
Facts:
Bob, who turns age 50 on his birthday in 2023, is the owner of an IRA from which he would like to start taking distributions beginning in 2023. He would like to avoid the Section 72(t) 10% additional tax imposed on early distributions by taking advantage of the SoSEPP exception.
- Bob’s IRA account balance is $400,000 as of December 31, 2022 (the last valuation date prior to the first payment), and he has made no contributions to or subtractions from the account between December 31, 2022, and the date he begins his SoSEPP.
- Assume 120% of the applicable federal mid-term rate is 2.98%. For the fixed amortization and fixed annuitization methods, Bob chooses to use a rate of 4%, which is not greater than the 5% limit specified in Q&A 4.
- Bob chooses to determine his SoSEPP over his own life expectancy only.
Examples:
1. RMD method
Under the RMD method, a payment under a SoSEPP is determined by dividing the account balance by a life expectancy determined under Q&A 5 above, using attained age(s) in the calendar year of the distribution. A new annual amount is determined in this manner each year.
Bob calculates his first annual amount by dividing the account balance ($400,000) by the single life expectancy (36.2) obtained from the Single Life Table, using attained age 50 ($400,000/36.2 = $11,050).
For subsequent years, Bob will calculate the annual amount by dividing the account balance as of December 31 preceding the year the annual amount is redetermined, the single life expectancy (36.2) obtained from the Single Life Table, using his attained age as of his birthday in the calendar year during which the annual amount is redetermined. For example, if Bob's IRA account balance, after the 2023 annual amount has been paid, is $408,304 on December 31, 2023, the second annual amount is calculated by dividing the December 31, 2023 account balance ($408,304) by the single life expectancy (35.3) obtained from the Single Life Table using age 51 ($408,304/35.3 = $11,567).
2. Fixed amortization method
The fixed amortization method results in the level amortization of the account balance over a specified number of years determined using a permitted interest rate under Q&A 4 and life expectancy under Q&A 5. The specified number of years is equal to the life expectancy under Q&A 4 (in this case, Bob selected the Single Life Table), 36.2 years. In this case, the interest rate Bob selected was 4.0%, which satisfies the rule in Q&A 4. An amortization factor based on 36.2 years and the selected interest rate of 4.0% is equal to 18.9559. This number was computed as the present value factor of $1.00 per year payable at the end of each year for 36.2 years using an interest rate of 4.0%. Thus, the annual amount for each year is $400,000 divided by 18.9559, or $21,102. Once the annual amount is calculated and paid under this method, the same dollar amount must be distributed in subsequent years.
3. Fixed annuitization method
Under the fixed annuitization method, the annual payment amount under a SoSEPP is determined by dividing the account balance by an annuity factor that is the present value of $1.00 per year beginning at the taxpayer’s age and continuing for the life (or lives) of the taxpayer (or taxpayer and taxpayer’s beneficiary). The annuity factor is derived using the mortality rates in Table 4 in Section 1.401(a)(9)?9(e), and a permitted interest rate under Q&A 4. In this case, the interest rate Bob selected was 4.0%, which satisfies the rule in Q&A 4. The annuity factor computed is 18.1568. This factor was computed as the present value factor of an annuity for the taxpayer aged 50 of $1.00 per year payable at the end of each year the taxpayer is still alive using an interest rate of 4.0%. Thus, the annual amount for each year is $400,000 divided by 18.1568, or $22,030. Once the annual amount is calculated and paid under this method, the same dollar amount must be distributed in subsequent years.
Note: The SoSEPP is not considered to have commenced until the date the first payment is made to the taxpayer. The taxpayer should ensure that the SoSEPP commences within the calendar year for which the annual amount initially is determined.
