Form 1094-C is the transmittal an Applicable Large Employer sends to the IRS with its Forms 1095-C. It reports summary information about the employer's offers of health coverage under the Affordable Care Act. For calendar year 2025 it was due by March 2, 2026 on paper, or March 31, 2026 if filed electronically.
Everything here comes from the IRS Instructions for Forms 1094-C and 1095-C (2025), as of October 2026.
Which employers file 1094-C
An Applicable Large Employer is generally an employer with 50 or more full-time employees, including full-time equivalent employees, in the previous year. Each ALE Member, meaning each employer in an aggregated group, files its own forms. It must file Form 1095-C for every employee who was full-time for any month of the year, and one or more Forms 1094-C to transmit them.
The forms do two jobs. They tell the IRS whether the employer may owe an employer shared responsibility payment under section 4980H, and they help decide whether employees can get the premium tax credit.
The Authoritative Transmittal
An employer can send more than one Form 1094-C, but exactly one of them must be the Authoritative Transmittal, marked on Part I, line 19. That one carries the aggregate employer-level data for all full-time employees. In an aggregated group, each member files its own Authoritative Transmittal; there's never a single one for the whole group.
Deadlines for the 2025 calendar year
| Task | Deadline |
|---|---|
| File 1094-C and 1095-C on paper | March 2, 2026 |
| File 1094-C and 1095-C electronically | March 31, 2026 |
| Furnish 1095-C to full-time employees | March 2, 2026 |
| Automatic 30-day extension to file | Form 8809 by the original due date |
The normal rule is February 28 on paper or March 31 electronically, moved to the next business day when it falls on a weekend. Form 8809 gives an automatic 30-day extension with no signature or explanation, and a second 30 days may be available for hardship.
New for 2025: employees don't automatically get 1095-C
Employers no longer have to send Form 1095-C to everyone automatically. The furnishing requirement is met if the employer posts clear, conspicuous and accessible notice on its website that individuals can request a copy, and then sends it by the later of January 31, 2026 or 30 days after the request.
Paper or electronic: the 10-return rule
If you have to file 10 or more information returns of any kind during the year, you must file electronically, through the ACA Information Return (AIR) system. The count is in the aggregate, so a business with only a handful of 1095-C forms can still be caught by its other information returns.
Here's the number to remember: failing to e-file when required, without an approved waiver, can cost $340 per return unless there's reasonable cause, as of October 2026. Up to 10 returns can go on paper without that penalty. A waiver is requested on Form 8508, ideally at least 45 days before the due date, and only covers 1 tax year at a time.
Where paper returns go
The address depends on where the employer's principal business is. Employers whose principal business, office or agency is in one of the states on the IRS list, which includes Alaska, California, Colorado, Illinois, Michigan, Nevada, Oregon, Tennessee, Washington and Wisconsin, send paper returns to the Internal Revenue Service Center, P.O. Box 219256, Kansas City, MO 64121-9256. Employers whose principal place of business is outside the United States file with the Internal Revenue Service Center, Austin, TX 73301.
Protecting employee numbers
On the 1095-C copies furnished to employees, an employer may truncate Social Security numbers by showing only the last four digits and replacing the first five with asterisks or Xs. Truncation isn't allowed on the forms filed with the IRS. Penalties for late or wrong statements can be waived for reasonable cause, but they increase where there's intentional disregard of the filing and furnishing rules.
Correcting a 1094-C
- Only the Authoritative Transmittal is ever corrected; never correct a 1094-C that wasn't the authoritative one.
- File a standalone, fully completed Form 1094-C with the right information and mark the CORRECTED box.
- Don't attach any 1095-C forms to the corrected Authoritative Transmittal.
- When correcting a 1095-C instead, file the corrected 1095-C with a new 1094-C that is not marked CORRECTED.
Paper filers send the forms flat, not folded, stapled or paperclipped, by First-Class Mail, printed sideways in the wide page orientation, with Form 1094-C in package number one. Keep copies, or the ability to rebuild the data, for at least 3 years from the due date.
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The verdict
If you had 50 or more full-time staff, including equivalents, last year, 1094-C is a yearly job with hard dates. File electronically, make sure exactly one transmittal is authoritative, and use the new website-notice option for 1095-C only if someone will reliably answer copy requests within 30 days.
Frequently asked questions
What is Form 1094-C?
It's the transmittal Applicable Large Employers use to send Forms 1095-C to the IRS and report summary information about their offers of health coverage.
Who has to file Form 1094-C?
Each ALE Member, generally an employer with 50 or more full-time employees including full-time equivalents in the previous year.
When is Form 1094-C due for 2025?
March 2, 2026 if filed on paper, or March 31, 2026 if filed electronically.
What is an Authoritative Transmittal?
The one Form 1094-C, identified on Part I, line 19, that reports aggregate employer-level data for all full-time employees of the ALE Member.
Is e-filing Form 1094-C required?
Yes, if you file 10 or more information returns of any type during the year, unless you get a waiver.
What is the penalty for not e-filing 1094-C?
Up to $340 per return for failing to file electronically when required, unless there's reasonable cause, as of October 2026.
Can I get more time to file Form 1094-C?
Yes. Form 8809 gives an automatic 30-day extension if filed by the original due date, and an extra 30 days may be available for hardship.
Do employers still have to mail Form 1095-C to every employee?
Not for 2025. Website notice that copies are available meets the rule, as long as requested copies go out by the later of January 31, 2026 or 30 days after the request.
How long should I keep copies of Forms 1094-C and 1095-C?
Keep copies, or the ability to reconstruct the data, for at least 3 years from the due date of the returns.
