@RobertB4444
I believe that IRS page is out of date. It refers to age 70-1/2 for RMDs instead of age 72-1/2, and it refers to a 5 year rule instead of a 10 year rule. It appears that it has not been updated for the SECURE act.
In this case, it appears that which rule the wife is covered by depends on the age difference between the wife and the cousin, which is why TurboTax is asking for the birthdate.
Eligible designated beneficiaries.
An IRA beneficiary is an eligible designated beneficiary if the beneficiary is the owner's surviving spouse, the owner's minor child, a disabled individual, a chronically ill individual, or any other individual who is not more than 10 years younger than the IRA owner.
If the owner died on or after his or her required beginning date (defined earlier), and you are an eligible designated beneficiary, you must base required minimum distributions for years after the year of the owner's death on the longer of:
Designated beneficiary who is not an eligible designated beneficiary.
Distributions to a designated beneficiary who is not an eligible designated beneficiary must be completed within 10 years of the death of the owner. See 10-year rule, later.
