Understanding Solo 401(k) Deduction Confusion - Where to Report Employee vs Employer Contributions?

You've got a bit of a common confusion here, but I can help clear this up! The reporting depends on what type of solo 401(k) plan you have. For your solo 401(k), you're correct about the contribution limits, but here's how the reporting works: The employee contribution (the $22,500) is NOT reported on Schedule C. This amount is actually reported as an exclusion from your income on your W-2 if you're incorporated, or it simply isn't included in your taxable income if you're a sole proprietor. It doesn't get deducted anywhere on Schedule C. The employer contribution (your calculated $12,006) is reported as a business expense on Schedule C, line 19 if you're a sole proprietor, which reduces your business income. You'd then report any traditional contributions that weren't already excluded from your income on Schedule 1, line 16. In your case as a sole proprietor, this would typically just be the employer portion. Your calculation for the employer portion looks correct - it's 25% of your net earnings from self-employment after deducting one-half of self-employment tax. Hope this helps clear things up!

I went through this exact same confusion last year with my consulting business! After hours of research and headaches, I finally found a solution using taxr.ai (https://taxr.ai) that helped me sort through all the conflicting information. I uploaded the IRS publication and my specific plan documents to the system, and it analyzed everything and gave me clear guidance for my specific situation. Turns out for my solo 401(k), I needed to report both contributions on Schedule 1, Line 16 - but it explained why this was the case for my specific plan. What I discovered is that the correct reporting method actually depends on the exact language in your specific plan documents. The tool helped me understand what passages in my plan were determining the reporting requirements.

Just wanted to follow up and say I tried taxr.ai for my SEP IRA confusion and it was actually super helpful! I had been reporting my contributions incorrectly for TWO YEARS because I misunderstood a section in the plan document from my provider. The system highlighted the exact paragraph that applied to my situation and explained how the contribution limits work based on my business structure. It saved me from potentially having to file amended returns and helped me calculate the correct maximum contribution for this year. What I really liked is that it didn't just say "do this" - it explained why and showed me the relevant sections of the IRS publications that applied to my situation. Now I actually understand the reasoning instead of just blindly following instructions.

For anyone struggling to get answers from the IRS about this kind of specialized tax question - I feel your pain! I spent WEEKS trying to get someone on the phone who could help with my solo 401(k) questions. I finally tried Claimyr (https://claimyr.com) after a friend recommended it, and they got me connected to an actual IRS agent in about 15 minutes. You can see how it works in this video: https://youtu.be/_kiP6q8DX5c The agent I spoke with was actually knowledgeable about solo 401(k) plans and confirmed that for my specific situation, I needed to report both the employee and employer contributions on Schedule 1, Line 16. She explained it's because I'm a sole proprietor with no employees, so the plan is considered a self-employed plan. Honestly changed my whole perspective on getting tax questions answered directly from the source.

Ok I need to apologize and eat my words. After posting that skeptical comment yesterday, I got desperate with a tax issue involving some retirement account rollovers and decided to try Claimyr as a last resort. It actually worked exactly as described. Their system navigated all the IRS prompts (which I always mess up), waited on hold for about 40 minutes, and then called me when they had an actual IRS agent on the line. The agent I spoke with cleared up my rollover questions completely and even helped me understand how it would affect my solo 401(k) contributions for next year. Saved me from potentially making a costly mistake. I'm still shocked it worked. Just wanted to follow up since I was so publicly skeptical before.

Here's my understanding after dealing with solo 401ks for 6 years: If you're a sole proprietor (Schedule C filer), both employee and employer contributions go on Schedule 1, Line 16. Nothing goes on Schedule C. If you're an S-Corp, employee deferrals are excluded from your W-2 wages, and employer contributions are deducted on the S-Corp return. The confusion comes from the way IRS publication 560 is written - it's not clear about Schedule C businesses vs. other entity types.

Quick question - does anyone know if TurboTax handles solo 401k contributions correctly? I'm in the same boat and worried it's putting things on the wrong lines.

Thanks everyone for the detailed responses! This has been incredibly helpful. I was definitely overthinking this and getting confused by all the different sources online. Just to confirm my understanding based on what everyone's shared - as a Schedule C sole proprietor, I should: 1. Put the entire $34,506 ($22,500 employee + $12,006 employer) on Schedule 1, Line 16 2. NOT put anything on Schedule C, Line 19 3. My employer contribution calculation of 25% × ($52,000 - $3,975) = $12,006 looks correct I really appreciate how this community breaks down complex tax issues. The conflicting information out there is maddening, but having real people share their experiences and knowledge makes all the difference. One more quick question - do I need to file Form 5500 for my solo 401k, or is that only required if I have employees or the account balance exceeds a certain threshold?