I forgot to include my spouse on my tax extension — are they still covered?

Yes — the spouse is covered.

For a married couple filing jointly, the IRS treats the extension as applying to the entire joint return, even if the extension request (Form 4868) was submitted using only one spouse’s SSN.

A few key points to make it clear:

• A joint return is considered one return for both spouses, not two separate filings.
• When an extension is filed for that return, it extends the due date for both spouses.
• It’s common (and acceptable) for the extension to be submitted using just the primary taxpayer’s SSN.
• When the return is ultimately filed as Married Filing Jointly, both spouses are fully covered by that extension.

Important caveat:
This only applies if the final return is actually filed jointly. If they later chose to file separately, the spouse who wasn’t listed on the extension could have an issue.