ACA Reporting for Payroll: Forms 1094-C and 1095-C Guide
6/21/2026
ACA reporting is usually owned by benefits, and payroll usually supplies the data that determines whether it is right. Both the threshold question — are you an applicable large employer — and the month-by-month coding on every Form 1095-C depend on hours of service and compensation figures that exist only in payroll.
That makes this a payroll topic even when payroll does not file the forms.
Are You an Applicable Large Employer?
The reporting obligation and the employer shared responsibility provisions apply to an applicable large employer (ALE): generally an employer that averaged 50 or more full-time employees, including full-time equivalents, during the preceding calendar year.
The calculation, performed month by month and then averaged:
- Count full-time employees — those averaging at least 30 hours of service per week, or 130 hours per month
- Compute full-time equivalents — aggregate the hours of all non-full-time employees for the month, cap each individual at 120 hours, and divide the total by 120
- Add the two figures for each month
- Average the twelve monthly totals
Points that determine the answer:
- Aggregation rules treat related entities under common ownership as a single employer for the ALE determination. A group of small entities can be an ALE collectively while none is individually.
- The determination uses the prior year, so status is known in advance and does not fluctuate mid-year.
- A seasonal worker exception may apply where the 50-employee threshold is exceeded for no more than four months and the excess is attributable to seasonal workers.
- Hours of service includes hours worked and hours for which payment is made or due for vacation, holiday, illness, disability, layoff, jury duty, military duty, and leave of absence.
That last point is the one payroll must get right. Hours of service is broader than hours worked, and a calculation using only worked hours understates the count.
The Data Payroll Owns
For every employee, every month:
- Hours of service, including paid non-working time
- Employment start and termination dates
- Full-time or part-time status by the applicable measurement method
- Compensation — needed for the affordability safe harbors
- Whether a coverage offer was made, and to whom
- The employee's required contribution for the lowest-cost self-only minimum value option
- Enrollment or waiver
Variable-hour and seasonal employees are the difficult population, because their status must be determined by a measurement period — a look-back window during which hours are averaged — followed by an administrative period and then a stability period during which the determined status holds regardless of subsequent hours.
Getting this right requires hours history by employee by month for a rolling period, which is a payroll data problem before it is a benefits one.
The Forms
Form 1095-C — one per full-time employee, furnished to the employee and filed with the IRS. Three parts:
- Part I — employee and employer identifying information
- Part II — the substance: month-by-month codes describing the offer of coverage, the employee's required contribution, and any applicable safe harbor
- Part III — covered individuals, completed where the employer sponsors a self-insured plan
Form 1094-C — the transmittal, filed once per ALE member. It reports the ALE member's identifying information, whether minimum essential coverage was offered by month, full-time employee counts and total employee counts by month, and any transition relief or aggregation information.
Part II Coding Is Where Errors Live
Part II uses two code series, and the combinations carry specific meanings.
The offer-of-coverage series describes what was offered for each month — whether minimum essential coverage providing minimum value was offered to the employee, to the employee and dependents, or to the employee, spouse, and dependents; whether the offer was made for all twelve months; and whether no offer was made.
The safe harbor and relief series describes why no penalty should apply for a month where no qualifying offer was made — the employee was not employed, was not full-time, was in a limited non-assessment period, enrolled in coverage, or the offer satisfied an affordability safe harbor.
Two structural error patterns:
Inconsistent code combinations. Certain offer codes cannot logically pair with certain safe harbor codes. Automated checks catch these, and the resulting correspondence is avoidable.
Coding from annual data. Part II is month by month. An employee hired in April, becoming eligible in July, and terminating in November has a different code pattern in each phase. Coding a single value across all twelve months is a common shortcut and a reliable error.
Our ACA Reporting Requirements session covers the coding framework.
Affordability Safe Harbors
Coverage must be affordable — the employee's required contribution for the lowest-cost self-only minimum value coverage cannot exceed a specified percentage of household income, a percentage that is indexed annually.
Because employers cannot know household income, three safe harbors permit using a proxy:
- Form W-2 safe harbor — based on the employee's Box 1 wages for the year
- Rate of pay safe harbor — based on the hourly rate or monthly salary at the start of the coverage period
- Federal poverty line safe harbor — based on the applicable federal poverty guideline
Each has conditions and each produces a different answer for the same employee. The safe harbor used is reported in Part II, and it may be applied on a reasonable-category basis rather than uniformly.
Payroll supplies the compensation figures for the first two. Note that the affordability percentage changes annually, so a contribution that was affordable last year may not be this year without any change in the employee's cost.
Deadlines and Filing
|
Requirement
|
Timing
|
|
Furnish Form 1095-C to employees
|
Generally early March, with an available alternative furnishing method
|
|
File Forms 1094-C and 1095-C with the IRS
|
Generally March 31 for electronic filing
|
|
Electronic filing
|
Required at a low return threshold that captures most ALEs
|
Two changes worth knowing. First, an alternative to automatic furnishing is available: an employer may satisfy the requirement by posting a clear notice that statements are available on request and providing them on request within a specified period. This reduces the mailing burden meaningfully. Second, the electronic filing threshold has been reduced substantially and aggregates across information return types, so most ALEs must e-file.
Because deadlines have shifted through legislation and guidance in recent years, confirm current dates rather than relying on a prior year's calendar.
Penalties
Two distinct penalty regimes, and employers frequently conflate them.
Information reporting penalties apply per form for failure to file, late filing, and incorrect information — assessed twice in effect, once for the IRS filing and once for the employee statement — with reductions for prompt correction.
Employer shared responsibility payments are separate and larger. They arise where an ALE either fails to offer minimum essential coverage to substantially all full-time employees and at least one receives a premium tax credit, or offers coverage that is not affordable or does not provide minimum value and an employee receives a credit. These are assessed per employee and are materially more expensive than reporting penalties.
The practical link between them: the IRS identifies potential shared responsibility exposure from the Forms 1095-C you file. Coding errors can generate a proposed assessment for coverage you actually offered correctly — which then has to be disputed with documentation. Accurate coding is not merely a reporting obligation; it is the defense against a much larger assessment.
Measurement Methods for Variable-Hour Employees
The hardest ACA population is employees whose hours fluctuate, and the difficulty is entirely a payroll data problem.
Two permitted methods:
The monthly measurement method determines full-time status month by month based on actual hours of service in that month. Simple to understand, but it produces status that changes as hours change — which means eligibility and coverage offers that fluctuate, and administrative churn for both the employer and the employee.
The look-back measurement method uses three defined periods:
- A measurement period — a look-back window, within permitted limits, during which hours are averaged
- An administrative period — a buffer during which the determination is made and enrollment is handled
- A stability period — during which the determined status holds regardless of subsequent hours
The stability period is the point of the method. An employee determined full-time during the measurement period must be treated as full-time for the entire stability period even if their hours later drop — and conversely, an employee determined part-time keeps that status through the stability period even if their hours rise.
Standard versus initial periods. Ongoing employees are measured using a standard measurement period applying to the whole category. New variable-hour, seasonal, and part-time hires are measured using an initial measurement period beginning at hire, then transition into the standard cycle. The overlap between an employee's initial and standard periods is a recurring source of coding errors.
Consistency requirements. The method chosen must be applied consistently across permitted employee categories, and the periods must satisfy length and alignment rules. You cannot select the method per employee.
What payroll must supply. Monthly hours of service — including paid non-working time — by employee, for a rolling window long enough to cover the longest measurement period plus the stability period. In practice this means retaining monthly hours history for two or more years and being able to produce it by employee on request.
That data retention requirement is worth confirming explicitly. A system that reports current-year hours easily but cannot produce a clean monthly history for a prior period makes the look-back method impossible to administer or defend.
Payroll's ACA Checklist
- [ ] Perform the ALE determination using prior-year data, applying aggregation rules across related entities
- [ ] Confirm hours of service includes paid non-working time, not just hours worked
- [ ] Maintain monthly hours history by employee for measurement periods
- [ ] Apply measurement, administrative, and stability periods consistently for variable-hour employees
- [ ] Supply compensation data for the affordability safe harbors
- [ ] Confirm the current-year affordability percentage and re-test contribution levels against it
- [ ] Verify Part II codes are assigned month by month, not annually
- [ ] Check for logically inconsistent code combinations before filing
- [ ] Complete Part III where the plan is self-insured
- [ ] Confirm the electronic filing threshold and credentials
- [ ] Confirm current-year furnishing and filing deadlines
- [ ] Retain the documentation supporting each coding decision — it is the defense against a proposed shared responsibility assessment
- [ ] Reconcile the full-time employee counts on Form 1094-C to your own monthly determination
Frequently Asked Questions
Who has to file Forms 1094-C and 1095-C?
Applicable large employers — generally those averaging 50 or more full-time employees including full-time equivalents during the preceding calendar year. Aggregation rules treat related entities under common ownership as a single employer for this determination, so a group of small entities can be an ALE collectively even though none reaches 50 individually.
How do you calculate full-time equivalents for ALE status?
For each month, count employees averaging at least 30 hours of service per week or 130 hours per month as full-time. Then aggregate the hours of all other employees for that month, capping each individual at 120 hours, and divide by 120 to get full-time equivalents. Add the two figures for each month and average the twelve monthly totals.
What counts as hours of service for ACA purposes?
Hours actually worked plus hours for which payment is made or due for vacation, holiday, illness, disability, layoff, jury duty, military duty, and leave of absence. This is broader than hours worked, and a calculation using only worked hours understates the count — which can produce a wrong ALE determination and wrong full-time status determinations.
What are the ACA affordability safe harbors?
Three permitted proxies for household income, which employers cannot know: the Form W-2 safe harbor based on Box 1 wages, the rate of pay safe harbor based on the hourly rate or monthly salary at the start of the coverage period, and the federal poverty line safe harbor. Each has its own conditions and produces a different result for the same employee. The affordability percentage is indexed annually, so a contribution affordable last year may not be this year.
When are 1095-C forms due?
Statements to employees are generally due in early March, and the IRS filing generally by March 31 for electronic filers, with electronic filing required at a low threshold that captures most ALEs. An alternative furnishing method is available: posting a clear notice that statements are available on request and providing them within a specified period. Because these dates have shifted through recent legislation, confirm current-year deadlines.
What is the penalty for incorrect ACA reporting?
Information reporting penalties apply per form for failure to file, late filing, and incorrect information — effectively twice, once for the IRS filing and once for the employee statement — with reductions for prompt correction. Separately and more significantly, employer shared responsibility payments are assessed per employee where coverage was not offered, not affordable, or did not provide minimum value. Because the IRS identifies that exposure from the Forms 1095-C themselves, coding errors can trigger a proposed assessment for coverage that was actually offered correctly.
Going Deeper
ACA deadlines, the affordability percentage, and the electronic filing threshold change annually, and furnishing requirements have been modified by recent legislation. Confirm current-year requirements against IRS guidance and coordinate coding decisions with whoever administers your health plan.
{
"@context": "https://schema.org",
"@graph": [
{
"@type": "Organization",
"@id": "https://www.payrolltrainingcenter.com/#organization",
"name": "Payroll Training Center",
"url": "https://www.payrolltrainingcenter.com/"
},
{
"@type": "WebSite",
"@id": "https://www.payrolltrainingcenter.com/#website",
"name": "Payroll Training Center",
"url": "https://www.payrolltrainingcenter.com/",
"publisher": {
"@id": "https://www.payrolltrainingcenter.com/#organization"
}
},
{
"@type": "WebPage",
"@id": "https://www.payrolltrainingcenter.com/blog/aca-reporting-for-payroll#webpage",
"url": "https://www.payrolltrainingcenter.com/blog/aca-reporting-for-payroll",
"name": "ACA 1095-C Reporting: Forms 1094-C and 1095-C Guide",
"description": "ACA 1095-C reporting for payroll — determining ALE status, the hours data payroll owns, Part II codes, affordability safe harbors, deadlines, and penalties.",
"isPartOf": {
"@id": "https://www.payrolltrainingcenter.com/#website"
},
"breadcrumb": {
"@id": "https://www.payrolltrainingcenter.com/blog/aca-reporting-for-payroll#breadcrumb"
}
},
{
"@type": "BlogPosting",
"@id": "https://www.payrolltrainingcenter.com/blog/aca-reporting-for-payroll#article",
"headline": "\"ACA Reporting for Payroll: Forms 1094-C and 1095-C Guide\"",
"name": "\"ACA Reporting for Payroll: Forms 1094-C and 1095-C Guide\"",
"description": "ACA 1095-C reporting for payroll — determining ALE status, the hours data payroll owns, Part II codes, affordability safe harbors, deadlines, and penalties.",
"url": "https://www.payrolltrainingcenter.com/blog/aca-reporting-for-payroll",
"inLanguage": "en-US",
"isPartOf": {
"@id": "https://www.payrolltrainingcenter.com/#website"
},
"mainEntityOfPage": {
"@id": "https://www.payrolltrainingcenter.com/blog/aca-reporting-for-payroll#webpage"
},
"author": {
"@type": "Organization",
"name": "Payroll Training Center",
"url": "https://www.payrolltrainingcenter.com/"
},
"publisher": {
"@id": "https://www.payrolltrainingcenter.com/#organization"
},
"keywords": "ACA 1095-C reporting",
"articleSection": "Compliance"
},
{
"@type": "BreadcrumbList",
"@id": "https://www.payrolltrainingcenter.com/blog/aca-reporting-for-payroll#breadcrumb",
"itemListElement": [
{
"@type": "ListItem",
"position": 1,
"name": "Home",
"item": "https://www.payrolltrainingcenter.com/"
},
{
"@type": "ListItem",
"position": 2,
"name": "Blog",
"item": "https://www.payrolltrainingcenter.com/blog"
},
{
"@type": "ListItem",
"position": 3,
"name": "\"ACA Reporting for Payroll: Forms 1094-C and 1095-C Guide\""
}
]
},
{
"@type": "FAQPage",
"@id": "https://www.payrolltrainingcenter.com/blog/aca-reporting-for-payroll#faq",
"mainEntity": [
{
"@type": "Question",
"name": "Who has to file Forms 1094-C and 1095-C?",
"acceptedAnswer": {
"@type": "Answer",
"text": "Applicable large employers — generally those averaging 50 or more full-time employees including full-time equivalents during the preceding calendar year. Aggregation rules treat related entities under common ownership as a single employer for this determination, so a group of small entities can be an ALE collectively even though none reaches 50 individually."
}
},
{
"@type": "Question",
"name": "How do you calculate full-time equivalents for ALE status?",
"acceptedAnswer": {
"@type": "Answer",
"text": "For each month, count employees averaging at least 30 hours of service per week or 130 hours per month as full-time. Then aggregate the hours of all other employees for that month, capping each individual at 120 hours, and divide by 120 to get full-time equivalents. Add the two figures for each month and average the twelve monthly totals."
}
},
{
"@type": "Question",
"name": "What counts as hours of service for ACA purposes?",
"acceptedAnswer": {
"@type": "Answer",
"text": "Hours actually worked plus hours for which payment is made or due for vacation, holiday, illness, disability, layoff, jury duty, military duty, and leave of absence. This is broader than hours worked, and a calculation using only worked hours understates the count — which can produce a wrong ALE determination and wrong full-time status determinations."
}
},
{
"@type": "Question",
"name": "What are the ACA affordability safe harbors?",
"acceptedAnswer": {
"@type": "Answer",
"text": "Three permitted proxies for household income, which employers cannot know: the Form W-2 safe harbor based on Box 1 wages, the rate of pay safe harbor based on the hourly rate or monthly salary at the start of the coverage period, and the federal poverty line safe harbor. Each has its own conditions and produces a different result for the same employee. The affordability percentage is indexed annually, so a contribution affordable last year may not be this year."
}
},
{
"@type": "Question",
"name": "When are 1095-C forms due?",
"acceptedAnswer": {
"@type": "Answer",
"text": "Statements to employees are generally due in early March, and the IRS filing generally by March 31 for electronic filers, with electronic filing required at a low threshold that captures most ALEs. An alternative furnishing method is available: posting a clear notice that statements are available on request and providing them within a specified period. Because these dates have shifted through recent legislation, confirm current-year deadlines."
}
},
{
"@type": "Question",
"name": "What is the penalty for incorrect ACA reporting?",
"acceptedAnswer": {
"@type": "Answer",
"text": "Information reporting penalties apply per form for failure to file, late filing, and incorrect information — effectively twice, once for the IRS filing and once for the employee statement — with reductions for prompt correction. Separately and more significantly, employer shared responsibility payments are assessed per employee where coverage was not offered, not affordable, or did not provide minimum value. Because the IRS identifies that exposure from the Forms 1095-C themselves, coding errors can trigger a proposed assessment for coverage that was actually offered correctly."
}
}
]
}
]
}
