401(k) and IRA'a are different retirement plan *types* and each has it's own separate RMD requirements and rules - totally separate RMD's and cannot be mixed.
As far as IRA's are concerned, you only have *one* IRA, and it is the aggregate total value of all IRA accounts (you can have as as many IRA accounts as you want) but the total RMD is calculated from the aggregate total value of all IRA accounts so it does not matter which account, or accounts that the RMD comes from since it is all the same IRA for tax purposes. The IRA RMD must come *from* the IRA and nowhere else.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**