Controlled Group Rules in Year of Business Sale

[Jeff G.]

Hello, 

I just came across a situation I'm struggling to navigate, would really appreciate input from more experienced folks in the forum. Scenario below:

 

1. Married clients own two companies in a controlled group, business "A" with W-2 employees and business "B" with only spousal employees (real estate holding company with s-corp election). Neither company offered a retirement plan.

2. Business A has been sold effective 9/1/24. If Business B were to create a solo 401k plan with a 10/1 adoption date, would controlled group rules still apply for the remainder of 2024 tax year?

 

Thanks in advance to anybody who's willing to help me think through this puzzle!