Determining SEP Contribution with Spousal Roth 401k is confusing me

[Tonyc2000]

My wife and I are 66.   I am self employed and want to contribute to an existing SEP IRA. My wife is employed by a corporation and she contributed $11,520 to Roth 401(k).   At the end of TT Deductions/Credits section, software says "Amount to be contributed by plan Due Date" is  $5208.  Fine.  Very next page says "Here are your 2018/2019 Deductions and Credits".  That page has a section called Deductions and a line that says "Self-Employed SEP or SIMPLE" ........$16,728.  That number is clearly the sum of the $5208 and $11520.  But why is it adding a pre-tax and post-tax contribution to get a total deduction?  And, more importantly, How much should I contribute to my SEP ?  $16,728 or $5,208?   Thanks to All.

[Country Apple]

Seems like you erroneously  entered your wife’s Roth 401k under the retirement contributions section.

[Tonyc2000]

Wife's Roth 401(k) contribution is reported on her W2, Box 12, Code AA.  But, in the Retirement section of Business Deductions, it asks whether my wife contributed to Roth 401(k).  My answer was Yes and entered the amount.  Then I ask it to Maximize my contribution to SEP.    At the end of the Deductions and Credits section, it triggers these two conflicting screens with two different SEP contributions...  thanks for your help.

[Country Apple]

Just a guess, but I believe that if you input your wife’s 401k deferral as part of her employee W2, you would NOT also list it under the Self Employed Individual and Roth 401(k) plans.  That section under the business deductions is for your business only and you would not put her Employee 401(k) there.

[Tonyc2000]

Yes, I absolutely agree. TT should 'know' that my wife had a Roth 401(k) because it's on her W2.

But, the very first question under in the section called (Wages&Income>BusinessDeductionsAndCredits>SelfEmployedRetirementPlans) is"Did you or your Wife contribute to Individual or Roth 401(k) ?"    I suspect it does that because there are limits to total contributions that a family can make.  So, I say "yes" and enter the amount.  Then, I say "maximize" my SEP contribution. Fine so far.   

But, the final result of the SEP "interview" in this section is a very murky conclusion regarding how much I should contribute to my SEP.  Two different numbers are given on two different concluding pages.

Thanks for taking a shot at this.

[Country Apple · Accepted solution]

If you click on the "Learn More" button at that first question, I think they're asking the question as it relates to SELF-EMPLOYED INDIVIDUAL & ROTH 401(K) PLANS.

https://www.irs.gov/pub/irs-pdf/p560.pdf

[Tonyc2000]

Yes, County Apple I think you are correct. 

To me, the question "Did you or your wife contribute to a Roth 401(k)" is a little misleading, as stated.   Admittedly, it is in the Business Deductions section, but it might have been better worded as "Did you or your wife contribute to a Roth 401(k) as it relates to the Sole Proprietorship".    

On a subsequent attempt, I answered "No" to that question and the SEP contribution began to appear in a way that made sense. 

Thanks for all your help