If you are the spouse of the deceased and the sole beneficiary of the account, you are permitted to treat the inherited IRA as your own. In that case, if you treat the IRA as your own in some year after the deceased's year of death, you are treated as IRA owner for the entire year (and subsequent years) and your RMD for that year will based on you as owner so it will be aggregatable with the RMDs of your other personal IRAs. Whether it's beneficial for a spouse beneficiary to treat the inherited IRA as the spouse's own will depend on the relative ages of the deceased and the spouse and whether it will be beneficial for the spouses' beneficiaries to be able to treat the IRA as inherited from the spouse as owner instead of as successor beneficiaries.
A non-spouse beneficiary cannot treat the inherited IRA as their own.
