What it is. Tax-exempt organisations don't pay tax on most investment income, but they do on unrelated business taxable income, such as operating-business income from a partnership or income from debt-financed real estate. The 990-T is where that's reported and paid.
Who has to file. An exempt organisation (including pension trusts, IRAs and university endowments) with $1,000 or more of gross unrelated business income in the year. Fund K-1s are the most common reason endowments and foundations end up filing one, which is why so many prefer to invest through a blocker.
When it's due. For most exempt organisations, the 15th day of the 5th month after year-end (May 15 for a calendar year); for employees' trusts and IRAs, the 15th day of the 4th month (April 15). A six-month extension is available on Form 8868.
Worked example
A university endowment's K-1 from a real estate fund shows $90k of UBTI from debt-financed property. That's over the $1,000 threshold, so the endowment files Form 990-T by May 15 and pays tax on the $90k.
Where you'll see it: LP side-letter negotiations ("use reasonable efforts to avoid UBTI"), blocker decisions, and K-1 review for exempt investors.
See all 53 terms in the glossary
This glossary is general information, simplified for learning. It is not tax, legal or investment advice, and real structures turn on facts and documents not shown here.