CP2000 received for my 2018 Taxes. Excess Social security and RRT tax withheld defaulted to the primary person filing when the tax return got filed. Can I get some help?

The most common reason for this is filing a joint return and entering ALL of the W-2 income under only one spouse's name.  When you file a joint return your income is combined, but you have to enter the W-2 income under the correct screens on the income screens.  If you miss that and put it all under only one of your names it can look like you paid excess SS from the box 4's of the W-2's.  That results in a bigger refund---and now the IRS wants that money back.

Look at the W-2's you entered---what is in the box 4's on them?

For 2018 if you entered more than $7960.80 for one person that is why is showed up on the tax form as excess Social Security.  Unfortunately it is user error.  Several screens alert you to it -- you have to pay attention to the names on the income screens.

And if you did in fact make the mistake of entering all of the income for your W-2’s under only one spouse’s name, you may have made that same mistake on the next year’s tax return if you transferred all your data over from the past year to the next.  Check to see—before you get another IRS letter.

For 2019 the amount is $8239.80--more than that for one spouse causes the excess SS to be entered on the form.