Form 990 Schedule O Instructions: Supplemental Information Guide (2026)
Learn what goes on Form 990 Schedule O, which lines always need an explanation, and how to write clear, IRS-ready answers. Includes examples and FAQs.
What Is Form 990 Schedule O?
Schedule O (Form 990), Supplemental Information to Form 990 or 990-EZ, is the page where a nonprofit explains its answers in its own words. Every organization that files Form 990 must attach it. Organizations filing Form 990-EZ use it whenever a line asks for a description or explanation.
Most schedules ask for numbers. Schedule O asks for narrative. It tells the IRS, donors and watchdog groups how your board works, how you review your return, and why certain figures look the way they do.
That makes Schedule O one of the most-read parts of the return. It is also one of the most often rushed. A vague or missing explanation can trigger IRS follow-up and weakens the public picture of your governance.
This guide explains who must file Schedule O, which Form 990 lines always need an explanation, how to write each entry, and the mistakes to avoid in 2026.
Who Must File Schedule O?
The answer depends on which return your organization files.
Form 990 filers: always required
If you file the full Form 990, Schedule O is mandatory. The reason is simple: two questions in Part VI (Governance) require a written explanation from every filer, with no exceptions. Line 11b asks how the return was reviewed, and line 19 asks how key documents are made public. Since every Form 990 must answer those two lines, every Form 990 needs Schedule O.
Form 990-EZ filers: required when a line asks for it
Form 990-EZ filers attach Schedule O only when the form tells them to. Common triggers include:
Line 8: describing "other revenue"
Line 16: describing "other expenses"
Line 20: explaining other changes in net assets or fund balances
Line 33: describing significant activities not previously reported to the IRS
Line 34: describing significant changes to governing documents
Who does not file Schedule O
Organizations filing Form 990-N (e-Postcard) or Form 990-PF do not use Schedule O. Not sure which return fits your nonprofit? See our guide to Form 990 filing requirements.
Which Form 990 Lines Need a Schedule O Explanation?
Two lines in Part VI need an explanation on every return. Several others need one only when you answer "Yes" or "No" in a certain way. The table below covers the lines filers most often have to explain.
| Form 990 Line | When Schedule O Is Required | What to Explain |
|---|---|---|
| Part VI, Line 11b | Always | How the return was reviewed before filing, and by whom |
| Part VI, Line 19 | Always | How governing documents, conflict of interest policy and financial statements are made available to the public |
| Part VI, Line 1a | If the board delegated broad authority to an executive committee | The committee's composition and the scope of its authority |
| Part VI, Line 2 | If any officers, directors or key employees have family or business relationships | The people involved and the type of relationship |
| Part VI, Line 3 | If management duties were delegated to a management company or other person | Who manages the organization and what duties were delegated |
| Part VI, Line 4 | If governing documents changed significantly | The changes made and when they took effect |
| Part VI, Line 5 | If the organization became aware of a significant diversion of assets | What happened and the corrective steps taken |
| Part VI, Lines 7a & 7b | If members or other persons elect board members or approve board decisions | Who holds those rights and how they are exercised |
| Part VI, Lines 8a & 8b | If board or committee meetings were not documented | Why meetings were not documented |
| Part VI, Line 12c | If the organization has a conflict of interest policy | How compliance with the policy is monitored |
| Part VI, Lines 15a & 15b | If compensation was set through a review process | The process used, including dates and comparability data |
| Part XI, Line 9 | If there are other changes in net assets | The nature and amount of each change |
| Part XII, Line 2c | If the audit oversight or auditor selection process changed | What changed during the year |
Always check the current IRS Instructions for Schedule O before filing, as line references can change from year to year.
How to Complete Schedule O: Step by Step
Schedule O has no fixed boxes. It is a blank page with your organization's name and EIN at the top. The quality of your entries is entirely up to you.
Enter your organization's name and EIN. Use exactly the same name and EIN that appear on page 1 of your Form 990 or 990-EZ.
List every line that needs an explanation. Go through your completed return and note each line that says "explain on Schedule O" or "describe in Schedule O." Start with Part VI, lines 11b and 19.
Label each entry with its part and line number. Begin every explanation with a clear reference, such as "Form 990, Part VI, Line 11b." This lets the IRS and readers match each answer to its question.
Write in the same order as the return. Follow the order of the form, from Part I to Part XII. Do not group entries by topic.
Be specific and factual. Name who did what, and when. Avoid one-word answers.
Add pages if needed. If you run out of space, attach additional Schedule O pages. There is no word limit.
Example entries
Here is how clear Schedule O entries look in practice:
Form 990, Part VI, Line 11b: The organization's Treasurer and outside tax preparer reviewed the completed Form 990. A copy was provided to every voting board member before filing. The board reviewed and approved the return at its meeting on [date].
Form 990, Part VI, Line 19: The organization makes its governing documents, conflict of interest policy and financial statements available to the public upon written request. Its three most recent Form 990s are available on its website.
Form 990, Part XI, Line 9: Unrealized loss on investments: ($12,450).
Each entry answers the question directly, names who was responsible, and avoids vague wording.
Common Schedule O Mistakes to Avoid
Most Schedule O problems come from rushing. Watch for these five errors.
Leaving lines 11b or 19 blank. These two explanations are required on every Form 990. An incomplete return can be rejected or treated as not filed.
Writing "N/A" or "See attached." The IRS expects a real description. Short placeholders do not answer the question.
Missing line references. An explanation without its part and line number is hard to match and easy to overlook.
Including private information. Schedule O is open to public inspection. Never include Social Security numbers, donor names or home addresses. Donor details belong on Schedule B, which is protected from public disclosure for most organizations.
Copying last year's text without checking it. Board members, policies and processes change. Update every entry so it reflects the current tax year.
Best practices
Keep a Schedule O template with your standard entries, and review it each year.
Have the board approve the governance explanations before filing.
Write for a donor, not only for the IRS. Clear governance answers build trust.
Make sure your Schedule O answers match related schedules, such as Schedule L for interested-person transactions and Schedule R for related organizations.
Frequently Asked Questions
Is Schedule O required for every Form 990?
Yes. Every organization filing Form 990 must attach Schedule O, because Part VI lines 11b and 19 require a written explanation on every return.
Do Form 990-EZ filers need to file Schedule O?
Only when a line on Form 990-EZ asks for a description or explanation, such as other revenue (line 8), other expenses (line 16) or other changes in net assets (line 20).
What should I write for Form 990 Part VI line 11b on Schedule O?
Describe who reviewed the return before filing, whether board members received a copy, and when the review took place. If no review happened, say so clearly.
Is Schedule O open to public inspection?
Yes. Schedule O is part of the public return. Do not include Social Security numbers, donor names or other private information.
How long can a Schedule O explanation be?
There is no word limit. Write enough to answer the question clearly, and attach additional Schedule O pages if needed.
Does Form 990-N or Form 990-PF use Schedule O?
No. Schedule O is used only with Form 990 and Form 990-EZ.
How do I reference a line on Schedule O?
Start each entry with the form, part and line number, for example "Form 990, Part VI, Line 19," then give the explanation.
Can I reuse last year's Schedule O explanations?
You can start from them, but review every entry. Changes in board members, policies or review processes must be reflected for the current year.
What happens if Schedule O is missing from Form 990?
The IRS may treat the return as incomplete. That can lead to correspondence, delays or penalties for filing an incomplete return.
Can a tax professional prepare Schedule O for my nonprofit?
Yes. A tax professional can draft your explanations from your board records and policies. Your board should still review the final text before filing.
Get Your Schedule O Right the First Time
Schedule O may be short, but it carries real weight. It shows the IRS and the public how your nonprofit is governed. Clear, specific and up-to-date explanations reduce IRS questions and build lasting donor trust.
Form990Series prepares and e-files Form 990, Form 990-EZ and every required schedule, including Schedule O, so your return is complete and accurate.
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