company a with 401(k) purchased by company b with simple ira

[Guest mrtnak]

I have a client, Company B, that is purchasing company A (assets). Company A maintains a 401(k) plan and Company B maintains a Simple IRA. For the 2005 plan year can this employer maintain both the 401(k) plan and the Simple IRA or do the newly acquired employees have to join the Simple IRA? Since Simple IRA's do not have all the testing requirements of a 401(k), if both plans are maintained, which testing should be done with both plans?