"Company A acquired Company B as a new wholly owned subsidiary via stock purchase. Company B will terminate its 401(k) plan prior to close. Company B employees will participate in Company A's SH plan 10/1/2021 but will remain on Company B's payroll through 12/31/2021. Company A plan is a QACA safe harbor plan and provides that Company A will make matching and non-elective contributions based on pay for the plan year.

[1] If Company B is not a participating employer in Company A's plan, does Company A need to use former Company B employee's plan year compensation when calculating non-elective contributions or can it use compensation from 10/1/2021-12/31/2021? [2] If Company B becomes a participating employer in Company A's plan, does Company A need to use former Company B employee's plan year compensation when calculating non-elective contributions or can it use compensation from 10/1/2021-12/31/2021?"