Can I reduce my self-employment tax deduction to allow for a full (trad.) IRA contribution deduction?

[dmertz]

No.  Your self-employment tax is determined on Schedule SE from your net profit from self-employment and Schedule SE requires that the deductible portion of self-employment taxes be include on Schedule 1 line 14.  The tax code does not permit you to decline the deduction on line 14.

[SamS1]

The only way to reduce the Adjustment to Income self employment tax deduction would be to lower your business income, which would lower your self employment taxes, which would decrease your self employment tax Adjustment to income.  But lowering your business income probably would be counter-productive to gaining the full IRA contribution.  

So that being said, you would need to increase your business income and this will increase your self employment tax deduction but your modified AGI would increase to allow for the full IRA deduction.  The down side is your self employment taxes will increase so you may end up with a higher tax bill to gain the full IRA deduction.

Here is a link to Self Employed and Small Business resources in TurboTax

[jdhlnh2018]

If I reduce my self-employment tax deduction by $579, and can increase the IRA contribution deduction by the same amount, I would get the full IRA deduction and avoid an excess contribution. The AGI remains the same and nothing else is impacted, except for avoiding the excess contribution. 

Why would the IRS require me to take the full self-employment tax deduction? 

[dmertz]

The deductible portion of self-employment tax is equivalent to the portion of a non-owner employee's Social Security and Medicare taxes that are paid by the employer and end up not being part of the net earnings of the employer.  IRS Pub 590-A makes this explicit by indicating that your compensation available to support an IRA contribution is your net profit from self-employment reduced by the amount of any self-employed retirement deduction and reduced by the deductible portion of self-employment taxes.  Even if you were permitted to decline to take the deduction for the deductible portion of self-employment taxes, doing so would not increase the amount that you would be permitted to contribute to an IRA because the deductible portion of self-employment taxes is explicitly treated as not being part of your "compensation."

[jdhlnh2018]

Thanks for your prompt reply!

[dmertz]

With regard to SamS1's reply, at this point your 2020 net profit from self-employment is what it is.  There is essentially no room for legitimate manipulation of your net profit because you must include all of your business's income and expenses.  You are not permitted to inflate your net profit by excluding from Schedule C actual expenses incurred by the business.

[jdhlnh2018]

Thanks - that helps my understanding of the self-employment tax a great deal. One more try - In that 2014 tax form, I listed $1409 in expenses on a Schedule C (license, travel, meals, other). What if, in an amended form, I omitted enough of the expenses to increase my income to the point that I could fully deduct my wife's $6,500 IRA contribution and avoid her excess contribution of $579? (She could only deduct $5921.) I acknowledge it's a round about way of avoiding the correction of this outstanding excess contribution...but is it a legitimate approach?

[dmertz]

As I said above, you must report all expenses that the business incurred.  You are not permitted to artificially inflate your net profit by omitting expenses.

[jdhlnh2018]

Darn...but thanks for the quick clarification.