Company X and Y form a controlled group. Plan A is a tiered Profit Sharing Plan and covers employees of X. Plan B is a 401(k) Plan and covers employees of Y.

Plan A satisfies 410(b) with respect to the Profit Sharing Contribution with all employees of X not receiving a Profit Sharing Contribution.

For 401(a)(4) general test for Plan A, must the denominator of the rate group calculations include the employees of X even though they are not covered under the Plan?

Yes, although don't you mean employees of Y since you state earlier that plan A covers employees of X.

Yes, I mean't to say:

For 401(a)(4) general test for Plan A, must the denominator of the rate group calculations include the employees of Y even though they are not covered under the Plan?

So I assume you do have to take into account these Y employees.

Thanks.

You assume correctly.