Deductions for contributions to a SEP IRA, Solo 401k, SIMPLE IRA, or Defined Benefit plans made by a self-employed Schedule C filer are noted on Schedule 1. S-Corp owners (Schedule E) work a little differently.
Self-employed individuals can contribute to a variety of employment-based retirement plans, including SEP-IRAs, Solo 401ks, SIMPLE IRAs and even defined benefit plans (i.e., traditional pensions). When the taxpayer is the owner of the business filing a Schedule C as a sole proprietor or LLC (or a general partner reporting partnership income on Schedule E), those employer contributions are eligible for a deduction on the taxpayer's personal return.
Schedule C Businesses:
Sole Proprietorships, Qualified Joint Ventures, and Single-Member LLCs (also referred to as disregarded entities by the IRS), as well as contract "gig" workers that receive 1099s instead of W-2 wage income generally record business activities on Schedule C.
If you are trying to model scenarios involving self-employed retirement plan contributions for a Schedule C business, you'll want to note them in the "Self-Employed Plans" Worksheet, which is accessible by clicking the pencil icon circled below in the "Schedule 1 Deductions (Above the Line)" section. Self Employed Plan contributions also impact the calculation of Qualified Business Income (QBI), as noted in this article.
Note: Contributions by the business to employees other than the owner should be reflected by adjusting the net profit reported on Schedule C.
As part of the Schedule C modeling upgrade in April 2024, we have incorporated a new "Self Employed Plans" Worksheet. Within the new worksheet, you can enter the self employed plan contributions where shown outlined in green below. 
You'll notice that we have also incorporated a popular request as well, as we'll note the maximum SEP Contribution, Solo 401(k) Contribution, or SIMPLE IRA Contribution that your self-employed client can make from their SE income. The entry here will roll back into the "Schedule 1 Deductions" section and your client's QBI Deduction for Schedule C will recalculate automatically. No more manual adjustments to get to the correct QBI!
NOTE: While we will call out the maximum SEP, Solo 401(k), or SIMPLE IRA contributions your client can make from SE Income, if you enter a SE plan contribution and later make changes to business income, please revisit this SE Plan Contributions section to ensure your entry is still within the max contribution limits.
Also, if your client has multiple 401(k)s or SEP accounts, be sure to be mindful of the overall aggregate plan limits across plan types as stated by IRS §415(c).
Schedule E Partnerships or S-Corps:
Alternatively, if the business in question is an S-Corp (or an LLC being taxed as an S-Corp), the employer portion of retirement plan contributions - including those made on behalf of the owner - are captured on the business return, which exists outside the scope of Holistiplan. The net impact of those contributions; however, reduce Schedule E net income that will ultimately be captured on Schedule 1.
One of the requirements of an S-Corp is that shareholders be paid a reasonable compensation in the form of wage income. As such, any employee contributions to self employed retirement plans are reflected by adjustments to taxable wages from the business in the Wages Worksheet within Scenario Analysis.
If you have any questions along the way as you model these self employed plan retirement contributions out within Holistiplan, please Contact our Support Team for further assistance!