Does filing a tax extension increase my audit risk?

No. The IRS has explicitly stated that filing an extension does not increase audit risk. It's standard practice for anyone with K-1 income.

Do I have to pay estimated taxes when I file an extension?

Yes. Form 4868 extends the time to FILE, not the time to PAY. Underpayment penalties apply to the gap between what you owe and what you paid by April 15.

How accurate does my tax estimate need to be?

Pay at least 100% of last year's total tax (110% if AGI > $150,000) to avoid underpayment penalties entirely, regardless of what you actually owe this year.

What if I file an extension and then get my K-1 before October?

File as soon as you have all K-1s. The extension gives you UNTIL October 15 — you don't have to wait. Most MLP investors who extend end up filing in June-August.

Can I file my extension electronically?

Yes. E-file through TurboTax, H&R Block, FreeTaxUSA, or IRS Free File. You can also get an automatic extension by making a payment through IRS Direct Pay — no separate form needed.

How to File a Tax Extension for Late K-1s — 2026 Guide

K-1s arrive late. That's normal. Here's how to file Form 4868 correctly, estimate your tax payment, and file once all your K-1 data is in hand.

By Lucas Andersen — Last updated March 6, 2026

Why MLP K-1s Are Always Late

Partnerships have until March 15 to issue K-1s. Many request their own extensions. Even "on time" K-1s leave less than a month before April 15. This is the normal experience for MLP investors.

How to File Form 4868

Form 4868 gives you an automatic 6-month extension to October 15. File electronically through tax software, IRS Free File, or simply make a payment through IRS Direct Pay — the payment itself serves as your extension.

Estimating Your Tax Payment

Safe harbor: pay at least 100% of last year's total tax (110% if AGI > $150,000) by April 15. This eliminates underpayment penalties regardless of what you actually owe.

Amended K-1s

If you extended and receive an amended K-1, use it in your original filing. If you already filed and receive an amended K-1 that's materially different, file Form 1040-X.