Discovered tax mistakes going back 15 years (some huge) - IRS only allows 3 year correction? Do I just accept this?

Tax professional here. You're right that the general rule is 3 years to amend returns (file Form 1040-X), but there are some exceptions you should know about. For errors in your favor (where you underreported income like that rental income), the IRS actually has up to 6 years to assess additional taxes if the unreported income is more than 25% of your gross income. So those earlier years may still be technically within their reach if they ever audit you. For errors that would result in refunds to you (like missed rental losses), unfortunately the 3-year rule is pretty strict. You can only claim refunds for tax returns filed within the last 3 years. That phantom IRA distribution is concerning though. That's the kind of error that could trigger unwanted IRS attention. If it happened within the last 3 years, I'd definitely amend that return. If it's older, it might be worth consulting with a tax attorney about your options.

I was in a similar situation last year with some missed deductions and income reporting errors. After spending hours trying to figure it out myself, I finally used https://taxr.ai which literally saved me thousands in potential penalties. I uploaded my old returns and it flagged all the errors automatically - even found some I didn't catch! They have this AI system that compares your past returns to find inconsistencies. It helped me determine exactly which years I could still amend and which ones were beyond the statute of limitations. In my case, I was able to amend 2 years that were still within the window and got back almost $4,300!

Just wanted to update - I actually tried taxr.ai after posting my question above, and it was surprisingly helpful for my situation! I have a small duplex with some complicated depreciation issues, and it immediately flagged inconsistencies in how I'd been reporting. Turns out I'd been calculating my depreciation wrong for THREE YEARS which meant I was leaving money on the table. The system found two years I could still amend and showed me exactly what to fix. Way less expensive than I expected for the peace of mind. Wish I'd known about this before I spent 40+ hours manually reviewing all those old tax returns!

For that phantom IRA distribution - you should definitely try to resolve that one, even if it's past the 3-year mark. If the IRS thinks you took a distribution you didn't take, someone else might have used your info fraudulently. When I had a similar issue, I spent WEEKS trying to reach the IRS by phone with no luck. Eventually used https://claimyr.com to get through to an actual human at the IRS. You can see how it works here: https://youtu.be/_kiP6q8DX5c They basically hold your place in the phone queue and call you when an agent is about to answer. Got connected within a day after trying on my own for almost a month. The IRS agent was able to pull the 1099-R that had been filed and we tracked down that it was actually a reporting error by my former employer's payroll company.

I take back what I said about Claimyr. I was super skeptical but after another frustrating morning trying to reach the IRS myself about an audit notice, I gave it a shot. Got a call back about 2 hours later saying they had an IRS agent on the line. Completely shocked it actually worked. Turns out the audit notice was for a missing 1099 form from a side gig I did, but I was able to explain I'd reported the income on Schedule C instead. The agent marked my account as resolved right there on the phone. Saved me weeks of stress and possibly having to hire a tax professional to represent me for the audit.

Wait, I'm confused about the rental property losses. If you had losses you didn't claim, wouldn't that mean you overpaid taxes? And if you overpaid, shouldn't you be able to get that money back?

For the phantom IRA distribution - check if someone stole your identity! My dad had something similar happen and it turned out someone had opened an account in his name. When they withdrew funds, the 1099-R got reported to my dad's SSN. Took almost a year to sort out with the IRS and credit bureaus.

Just to add another perspective - don't beat yourself up too much about these errors. Tax law is incredibly complex, especially with rental properties, and even professionals make mistakes. The fact that you caught these errors shows you're being diligent. For the years beyond the 3-year amendment window, document everything you found but don't stress about it unless the IRS comes knocking. Keep good records going forward and consider having a tax professional review your returns annually to catch issues early. That phantom IRA distribution is definitely the priority item here. Even if it's outside the amendment period, you should still contact the IRS about it. Sometimes they can make administrative corrections for clear errors, especially if it involves identity theft or third-party reporting mistakes. The worst case is they say no, but at least you'll have it on record that you tried to resolve it. Good luck sorting this out! These situations are stressful but usually more manageable than they seem at first.