I am not a tax expert by any means, but if the IRA withdrawal is from a regular IRA that requires you to report as income, then it is also income for determining how much of your SS is taxed. If the IRA withdrawal is from a Roth IRA and not reportable as income, then it has no affect on your SS tax obligations.
Note that not all regular IRA withdrawals are taxable (not to the extent you have basis) and not all Roth IRA withdrawals are not taxable (account not open long enough or otherwise non-qualified and after following ordering rules.
IRA withdrawals are not earned income and no SS tax is due on them.
I suspect that the source you quoted is confused or an editor inadvertently omitted something.
Yes, it is in error, unless it’s specifically talking about withdrawals of after-tax money. (I will point out that the subtitle on the article says “If you have after-tax money in your IRA, don’t pay taxes on it twice” so it’s not clear what type of withdrawals they are talking about when they answer that question.)
Since T-IRA withdrawals, after adjusting for any after-tax basis, are counted toward your AGI, they are also counted when calculating taxability of SS benefits. I will also point out that unless the total after-tax basis in your T-IRA account(s) is more than the total balance in the T-IRA account(s), there will always be at least some of the T-IRA withdrawal that counts toward your AGI.
As JAFO indicated, at least for now, qualified withdrawals from Roth IRAs are not taxable, and so do not count toward the taxability of your SS benefits. That said, I wouldn’t be at all surprised if, when Congress gets around to ‘saving’ SS again, they require that qualified Roth IRA withdrawals start being added into income that counts toward SS taxability, just like tax-free interest is added back in. Hopefully, they will also index, or at least increase, the income limits that they apply to “combined income” at that time, too.
In a quick read of that article, I found multiple errors. The one you questioned is only one of them. I would completely disregard that article. I have also contacted Investopedia and asked them to remove the article immediately. I recommend that others do the same. (aj? JAFO? I’m sure you both can spot at least one or two more that are either flat out wrong or very misleading.)
I used the “Contact Us” link way down at the very bottom of the page. (Past all of the links to other articles.)
Yes, I found that after @ptheland’s post. The first time I looked, I gave up too early. Sent in a request for them to delete the article and to hire authors, reviewers and fact checkers who were actually familiar with taxes.