See below: Check the preamble but it depends how the plan is written & the default language.
RMD REGS Annotated by Noel IceHere is the language I'm speaking about but have his CPA check out the full regs.
Default Rule for Post-death Distributions
These regulations, as did the 2001 proposed regulations, provide that, if an employee dies before the employee's required beginning date and the employee has a designated beneficiary, then the life expectancy rule in section 401(a)(9)(B)(iii) (rather than the 5-year rule in section 401(a)(9)(B)(ii)) is the default distribution rule.[27] Thus, absent a plan provision or election of the 5-year rule, the life expectancy rule applies in all cases in which the employee has a designated beneficiary, and the 5-year rule applies if the employee does not have a designated beneficiary [and dies prior to the RBD][28]. This is a change from the position in the 1987 proposed regulations that provided the 5-year rule as the default unless the spouse was the sole beneficiary.[29] Commentators pointed out that, as a result of the default rule under the 1987 regulations, some beneficiaries did not commence distributions under the life expectancy rules. In response to those comments, these final regulations provide a transition rule that permits beneficiaries subject to the 5-year rule under the 1987 proposed regulations to switch to the life expectancy rule, provided that all amounts that would have been required to be distributed under an application of the life expectancy rule are distributed by the earlier of December 31, 2003 or the end of the 5-year period following the year of the employee's death.[30]