Most tax-exempt organizations file one of three versions each year.
- Form 990-N: gross receipts normally $50,000 or less
- Form 990-EZ: gross receipts under $200,000 and total assets under $500,000
- Form 990: everyone else
Private foundations file Form 990-PF. The return is due on the 15th day of the fifth month after the year ends: May 15 for a calendar year.
Source: IRS, Form 990 series: which forms do exempt organizations file.