These are two terms I didn't know when I started my self directed retirement account journey. It's honestly something I avoided too. I always try to keep things simple, but hope that this helps understand what triggers these taxable events. UDFI (Unrelated Debt-Financed Income) If you buy rental property with debt financing in your IRA, you will be subject to the UDFI tax. If you earn 100 in net income and you financed 80% of the purchase price through a traditional bank, 80 dollars of that 100 is subject to UDFI. Ways to avoid UDFI - Purchase property without any debt financing. - Open solo 401k instead of self directed IRA. UBIT (Unrelated Business Income Tax) If you participate actively in a business that you own through your self directed IRA, the net income is subject to UBIT. If your portion of the net income of a company you own in your SDIRA is 100K, that entire amount is subject to UBIT. Ways to avoid UBIT - Be a passive investor in the business