Inherited IRA RMD's

[RWG1950]

Mom (age 88) dies 9-24-2023 with an IRA, naming her 4 adult children as equal beneficiaries.
She had taken her 2023 RMD before death.
Will be using 10 years as none of the benes qualify for the lifetime stretch.
Under the latest version of the Secure act, do the benes use their own d/o/b or mom's d/o/b to calculate their 2024 RMD's ?
Thanks for comments.

[terryats]

Generally, a designated beneficiary is required to liquidate the account by the end of the 10th year following the year of death of the IRA owner (this is known as the 10-year rule). An RMD may be required in years 1-9 when the decedent had already begun taking RMDs.You should use moms DOB

[RWG1950]

Terryats: Thanks for your reply to my post.
Assuming the factors in my original post, after looking at IRS pub 590-B (pages 11-12) it seems to say the beneficiary's age,
should be used with the single life table to calculate RMD's for a designated but non-eligible beneficiary.
Maybe I'm misinterpreting the info in the IRS pub 590.
What circumstances do you feel would cause a bene to have to use mom's age for their RMD calc ?

[New York Enrolled Agent]

From the proposed regulations 1.401(a)(9)-5

(1) Death on or after the employee's required beginning date

(ii) Employee with designated beneficiary. If the employee has a designated beneficiary as of the date determined under Sec. 1.401(a)(9)-4(c), the applicable denominator is the greater of--

(A) The designated beneficiary's remaining life expectancy; and

(B) The employee's remaining life expectancy.