ACA Compliance: What Employers Need to Know
ACA compliance for employers: the 50-FTE threshold, how to calculate it, what applies under 50 employees, deadlines, and current penalties.
ACA Compliance
What the law actually requires of your business, starting with whether it applies to you at all
Most articles about ACA compliance open with a list of everything you have to do. This one opens with a question that saves the majority of readers the rest of the article: how many full-time equivalent employees did you average last year?
If the answer is under 50, the employer mandate does not apply to your business. You are not required to offer health coverage under the Affordable Care Act, you generally do not file Forms 1094-C or 1095-C, and most of the penalty exposure people worry about is not yours. That is the actual answer for a large share of small businesses, and it is buried on page four of nearly every guide on this topic because the guides are written by vendors selling compliance software to companies that are already over the line.
What follows covers both cases honestly. How to run the calculation that tells you which one you are in, what the small handful of obligations look like if you are under the threshold, what happens as you approach it, and the full set of requirements if you are over it, with current figures from the IRS. This is general information rather than legal or tax advice, and the specifics of your plan and structure matter enough that a professional review is worth the cost before you rely on any of it. I built FirstHR for businesses of 5 to 50 people, which is to say mostly businesses that turn out not to be Applicable Large Employers.
What ACA Compliance Actually Means
Two things are worth separating immediately, because conflating them causes most of the confusion. The employer mandate is about whether you must offer coverage. Reporting is about what you must tell the IRS. They usually go together but not always: a small employer with a self-insured plan has a reporting duty and no mandate, which is a combination most guides never mention.
The third thing worth stating: the ACA does not require any employer to offer health insurance in the abstract. It creates a financial consequence for large employers who do not offer qualifying coverage when their employees then receive subsidized coverage through a marketplace. The distinction matters because it explains why the penalty structure works the way it does.
Does This Even Apply to You?
Before anything else, establish which side of the threshold you are on. This single determination decides roughly ninety percent of what you need to know.
| Your situation | Employer mandate | IRS reporting | Penalty exposure |
|---|---|---|---|
| Under 50 FTEs, fully insured plan or no plan | Does not apply | None. The carrier reports if you have a plan | None under section 4980H |
| Under 50 FTEs, self-insured or level-funded plan | Does not apply | Forms 1094-B and 1095-B | Reporting penalties only, not 4980H |
| Under 50 FTEs, offering an ICHRA | Does not apply | Forms 1094-B and 1095-B | Reporting penalties only |
| 50 or more FTEs, fully insured plan | Applies | Forms 1094-C and 1095-C | Full 4980H exposure |
| 50 or more FTEs, self-insured plan | Applies | Forms 1094-C and 1095-C, including enrollment data | Full 4980H exposure |
Read the first row carefully if you have fewer than 50 employees and buy a normal group plan from an insurance carrier, or offer nothing at all. Your ACA compliance obligation is close to zero. You should still run the calculation annually and keep the result, but there is nothing to file and no penalty to fear under the employer mandate.
The Applicable Large Employer Test
An Applicable Large Employer employed an average of at least 50 full-time employees, including full-time equivalent employees, during the preceding calendar year. Three details in that sentence do most of the work.
Preceding calendar year. Your status this year depends on last year's numbers, not on where you are today. A business that crosses 50 in the middle of this year becomes an ALE on January 1 of next year, which gives you a planning window most people do not realize they have.
Including full-time equivalents. The threshold is not 50 people on the payroll. Part-time hours are converted into equivalents and added to your full-time headcount. This cuts both ways: a business with 70 part-time employees may be under 50 FTEs, and a business with 45 full-time employees plus a handful of part-timers may be over.
Average. Twelve monthly figures averaged, not a snapshot. Seasonal businesses that spike above 50 for part of the year frequently average below it, and there is a separate seasonal worker exception that can apply where the excess is driven by workers employed 120 days or fewer in the year.
One complication worth naming for anyone who owns more than one business: controlled group and affiliated service group rules can require combining employee counts across commonly owned entities. Two separate 30-person companies with the same owner may together be an ALE. The IRS guidance on determining ALE status covers the aggregation rules, and this is one area where a professional review earns its fee.
Calculating Your FTE Count
The calculation is arithmetic, not judgment. It takes about twenty minutes once your hours data is in one place, and the hard part is having the hours data.
Two definitions anchor the whole thing. A full-time employee for ACA purposes averages at least 30 hours of service per week or 130 hours per month. That is lower than most businesses treat as full-time internally, which is why employers are frequently surprised by how many people count. And the 120-hour cap on part-time employees exists because anyone above 130 is already counted as full-time.
Hours of service includes more than hours worked. Paid vacation, holiday, illness, disability, jury duty, and military leave all count. For a business with generous paid leave, ignoring this can push your calculation meaningfully off. The full-time equivalent guide covers the FTE concept in other contexts, and the full-time hours guide covers why the ACA definition differs from the one you use internally.
A Worked Example
The lesson from this example is how close the line is and how little it takes to move. Twenty part-timers at 60 hours a month contribute 10 FTEs. If those same twenty people averaged 50 hours instead, the contribution drops to 8.3 and the business is under the threshold. Scheduling decisions made for operational reasons have compliance consequences that nobody connects at the time.
This is also why the calculation must be monthly rather than annual. A business that runs at 46 FTEs for nine months and 62 for three averages 50, which makes it an ALE. Looking only at a typical month would have produced the wrong answer.
If You Are Under 50: What You Actually Do
Short list. This is the section most guides skip entirely, and for many readers it is the only section that matters.
The self-insured point deserves expansion because it catches people. If you buy a traditional group health plan from an insurance carrier, the carrier is the coverage provider and handles Form 1095-B reporting for your employees. You do nothing. But if you self-insure, use a level-funded arrangement, or offer an individual coverage HRA, you become the coverage provider for reporting purposes and must file Forms 1094-B and 1095-B even though you are not an ALE and have no mandate.
That surprises employers who chose a level-funded plan or an ICHRA specifically because it seemed simpler. The employer mandate exemption and the reporting exemption are separate things, and only the first follows automatically from being under 50. The ICHRA and QSEHRA guide covers those arrangements, and the QSEHRA guide covers the small-employer version specifically.
On the broader benefits question: nothing here says you should not offer health coverage. Many small businesses do, for recruitment and retention reasons that have nothing to do with legal obligation. The small business benefits guide covers that decision on its merits.
Approaching the Threshold
The transition is the part almost no guide addresses, and it is where a growing business most needs the information. The good news is that the structure of the rule gives you more warning than you might expect.
| Where you are | What to do now | Why |
|---|---|---|
| Averaging under 40 FTEs | Run the calculation annually and file the result | No action needed beyond documentation. Do not buy compliance software yet |
| Averaging 40 to 47 FTEs | Start tracking hours monthly rather than reconstructing them | The data you will need is monthly. Building the habit before you need it is much cheaper than backfilling |
| Averaging 47 to 50 FTEs | Price coverage and model the cost of an offer | You may cross this year, which makes you an ALE next January. Knowing the cost changes hiring and scheduling decisions |
| Crossed 50 for the first time last year | You are an ALE now. Set up the offer and the reporting | The obligation is live for the current year, including the coverage offer and next spring's filing |
| Hovering near 50 year to year | Track continuously and consider whether to plan as if you are an ALE | Oscillating across the line means alternating obligations, which is harder to manage than simply complying |
The timing works in your favor here. Because ALE status uses the prior calendar year, a business that crosses 50 in, say, August has until January to prepare, and until the following spring to file anything. That is a genuine planning window rather than a scramble, provided you notice you crossed.
Noticing is the actual risk. Businesses do not track FTE counts as a matter of routine, so crossing the threshold is invisible until someone runs the calculation. The headcount planning guide covers building growth decisions around thresholds like this one, and the ACA threshold is one of several that arrive as a business scales.
The Employer Mandate
If you are an ALE, the requirement has three parts, and failing any of them creates exposure.
Offer coverage to at least 95 percent of full-time employees. The offer must extend to their dependent children, though not to spouses. Missing the 95 percent threshold, even by a small margin, exposes the entire full-time workforce to the section 4980H(a) penalty rather than just the employees who were missed, which is why this figure matters so much.
The coverage must provide minimum value. The plan has to cover at least 60 percent of the total allowed cost of benefits and provide substantial coverage of inpatient hospital and physician services. This is an actuarial determination normally confirmed by the carrier.
The coverage must be affordable. The employee's required contribution for the lowest-cost self-only option cannot exceed a set percentage of household income, or an approved substitute.
Determining who counts as full-time for the offer is its own exercise. For employees with predictable schedules, the monthly measurement method is straightforward. For variable-hour and seasonal employees, the look-back measurement method lets you use a measurement period of three to twelve months to establish status, followed by a stability period during which that status holds regardless of hours. Most businesses with hourly staff need the look-back method, and setting it up correctly is where a benefits advisor is genuinely useful. The IRS maintains detailed questions and answers on the employer shared responsibility provisions.
Affordability and Minimum Value
The affordability percentage is indexed annually and has moved a great deal, which catches employers who set a contribution once and left it.
| Plan year | Affordability percentage | Direction |
|---|---|---|
| 2024 | 8.39 percent | The lowest it has been |
| 2025 | 9.02 percent | Increased |
| 2026 | 9.96 percent | Increased again; the highest since the requirement took effect |
The 2026 figure of 9.96 percent comes from IRS Rev. Proc. 2025-25, issued in July 2025. Practically, an increase gives employers room: the same plan design that was borderline in 2025 comfortably clears the test in 2026, or the employer can raise the employee contribution somewhat and still comply.
Note that non-calendar-year plans use the percentage in effect at the start of their plan year. A plan year beginning in November 2025 uses 9.02 percent for its full duration, switching to 9.96 percent only at the next plan year start. This trips up employers who read a news item in July and adjust immediately.
Minimum value is a separate test and a plan must pass both. A cheap plan that employees can easily afford but that covers less than 60 percent of expected costs fails minimum value and leaves you exposed to the section 4980H(b) penalty despite being affordable.
The Three Safe Harbors
Employers do not know household income, which is what the affordability test technically measures. The IRS therefore permits three substitutes, and you can use different ones for different reasonable categories of employees.
| Safe harbor | How it works | Best for | Watch out for |
|---|---|---|---|
| Federal poverty line | Contribution capped at the affordability percentage applied to the applicable FPL figure, divided by twelve | Simplicity. Produces one dollar amount that works for every employee | The most conservative, so it usually permits the lowest employee contribution |
| Rate of pay | Hourly rate multiplied by 130 hours per month, then by the affordability percentage. Monthly salary for salaried staff | Hourly workforces where rates vary | Uses the lowest rate of pay in the period. A mid-year rate cut complicates it |
| Form W-2 wages | Box 1 wages from your company for that employee for the year, multiplied by the affordability percentage | Stable, salaried workforces | Only known at year end, so it is a retrospective check rather than a planning tool |
For most small businesses that become ALEs, the federal poverty line safe harbor is the practical choice. It gives you a single monthly dollar figure that applies to everyone, it is knowable in advance, and it does not require per-employee calculation. The tradeoff is that it caps the employee contribution lower than the other two would.
Reporting Requirements
Reporting is separate from the mandate and has its own forms, deadlines, and penalties.
| Form | Who files it | What it reports |
|---|---|---|
| Form 1095-C | Applicable Large Employers | The offer of coverage made to each full-time employee, month by month, using a series of codes |
| Form 1094-C | Applicable Large Employers | The transmittal that accompanies the 1095-C forms, with aggregate employer-level information |
| Form 1095-B | Coverage providers, including small self-insured employers | Actual enrollment in minimum essential coverage for each covered individual |
| Form 1094-B | Coverage providers | The transmittal accompanying the 1095-B forms |
The coding on Form 1095-C is where most errors originate. Lines 14, 15, and 16 use series of codes describing what was offered, what it cost, and why any safe harbor applies, for each month. Miscoding is common and is a frequent cause of an IRS letter proposing a penalty that the employer does not actually owe. The IRS instructions for Forms 1094-C and 1095-C define the codes.
Electronic filing is required for any filer of 10 or more information returns, which in practice means nearly every ALE. Paper filing survives only for very small filers, which mostly means small self-insured employers with a handful of covered people.
Deadlines
Two separate obligations with two separate dates. Employers focused on the filing deadline sometimes miss that furnishing comes first.
| Obligation | Date for the 2025 tax year | Notes |
|---|---|---|
| Furnish Forms 1095-C to employees, or post the alternative notice | March 2, 2026 | Reflects a permanent automatic 30-day extension from January 31 |
| Paper file Forms 1094-C and 1095-C with the IRS | March 2, 2026 | Permitted only for filers of fewer than 10 information returns |
| Electronically file Forms 1094-C and 1095-C | March 31, 2026 | Required for filers of 10 or more returns, which covers nearly all ALEs |
| Respond to a Letter 226-J penalty notice | Within 90 days of the letter | Extended by recent legislation from the previous 30-day window |
| Keep the alternative furnishing notice posted | Through October 15, 2026 | Applies if you used the website notice method rather than furnishing directly |
These dates shift year to year, partly because February 28 sometimes falls on a weekend. Confirm the current cycle rather than carrying forward last year's dates.
A note for employers with staff in states operating their own individual mandate: several states have separate furnishing and reporting requirements with earlier deadlines that do not follow the federal relief. If you have employees in one of those states, check the state rule separately. The California compliance guide covers one of the more demanding examples.
Penalties
Two employer shared responsibility penalties, both indexed annually, and they are mutually exclusive for any given employee in any given month.
| Penalty | When it applies | 2025 amount | 2026 amount |
|---|---|---|---|
| Section 4980H(a) | You failed to offer minimum essential coverage to at least 95 percent of full-time employees, and at least one received a premium tax credit | $2,900 per full-time employee annually, less the first 30 | $3,340 per full-time employee annually, less the first 30 |
| Section 4980H(b) | You offered coverage, but it was unaffordable or lacked minimum value, for each employee who received a premium tax credit | $4,350 per affected employee annually | $5,010 per affected employee annually |
The 2026 figures come from IRS Rev. Proc. 2025-26. The structural difference matters enormously: the (a) penalty applies to your entire full-time workforce less the first 30 employees, while the (b) penalty applies only to the specific employees who received a subsidy. For an employer with 60 full-time employees, missing the 95 percent offer threshold in 2026 exposes 30 employees at $3,340 each, roughly $100,200 annually. Offering coverage that is unaffordable to three employees who then get subsidies exposes about $15,030.
Both are calculated monthly rather than annually, so a failure lasting two months costs two twelfths of the annual figure. Neither is deductible for federal income tax purposes.
Reporting penalties are separate and apply per form for late or incorrect filings, with higher amounts for intentional disregard. An employer who offers perfect coverage and files late still has exposure.
Recent Changes Worth Knowing
Three developments have changed the practical picture over the last two years.
The alternative furnishing method. Legislation signed in December 2024 means ALEs no longer have to automatically mail Form 1095-C to every full-time employee. Instead, you may post a clear, conspicuous, and accessible notice on your website stating that forms are available on request, keep it posted through October 15, and furnish a form within 30 days of any request. This is a real administrative saving for employers with a large hourly workforce, though it creates a request-tracking obligation in exchange, and it does not override state-level furnishing rules.
A longer response window for penalty notices. Companion legislation extended the window for responding to an IRS Letter 226-J from 30 days to 90. This matters because a substantial share of proposed assessments trace to reporting errors rather than actual compliance failures, and 30 days was rarely enough to reconstruct a year of coverage data and respond properly.
Enhanced marketplace subsidies lapsed. The enhanced premium tax credits introduced in 2021 and extended through 2025 expired at the end of 2025. Research from KFF estimated that expiration would more than double what subsidized enrollees pay on average, a 114 percent increase from roughly $888 in 2025 to $1,904 in 2026. As of early 2026 the question remained legislatively live, with proposals to restore them under consideration, so confirm the current status before relying on this.
What HR Actually Does Day to Day
Searches for ACA HR compliance are usually looking for this: not the law, but the operational work. Four things, and at a small business they land on whoever handles HR, which is often the owner.
| Task | What it involves | Where it goes wrong |
|---|---|---|
| Track hours of service | Monthly hours for every employee, including paid leave, not just hours worked | Reconstructing hours in February from incomplete records. This is the root cause of most other failures |
| Determine full-time status | Apply the monthly or look-back measurement method consistently to identify who must receive an offer | Applying different methods to different people without a defensible basis, or never formally choosing one |
| Document offers and declines | Record what was offered to whom, when, at what cost, and what they elected | Relying on the broker's enrollment records, which show who enrolled but not who was offered and declined |
| Produce the reporting data | Assemble monthly coverage codes for each employee for Forms 1095-C | Coding errors on lines 14 through 16, which generate IRS letters proposing penalties that are not actually owed |
The first row is the foundation. Everything else is derived from hours data, and a business that cannot produce accurate monthly hours cannot run the FTE calculation, cannot determine full-time status, and cannot code the forms. The time and attendance guide covers building that record, and the payroll records guide covers retention requirements.
Common Mistakes
These recur across small and mid-sized employers. Most are the result of treating ACA compliance as an annual event rather than a data problem that runs all year.
The costliest is the first, and it runs in both directions. Businesses assume they are ALEs because they have more than 50 people and spend money on compliance they do not need. Others assume they are safe because they have 45 employees and never notice that part-time hours pushed them over. Both are solved by twenty minutes and a spreadsheet.
How FirstHR Fits
FirstHR handles the operational layer underneath all of this: employee records with accurate hours, employment status and classification in one place, document management so plan documents and coverage records are findable rather than scattered, and structured onboarding so benefits eligibility is handled consistently for every hire. It is built for businesses of 5 to 50 people at flat-fee pricing, which is to say for businesses that are usually below the ALE threshold and need to know it rather than guess.
What we are not is an ACA filing service or a benefits broker, and you should be cautious of anyone claiming one tool covers the whole picture. If you are an ALE, form generation and filing is a specialized function and you will want either a broker, a payroll provider, or dedicated reporting software. What a system does is ensure the underlying data exists and is accurate, since a filing service can only work with what you give it.
For the broader compliance picture that ACA sits inside, the HR compliance guide covers the other federal thresholds that arrive as you grow. General small-employer guidance is available through the healthcare.gov employer resources, and the IRS information center for ALEs collects the official material in one place.
This article is general information and not legal or tax advice. ACA determinations depend on facts specific to your business, including ownership structure and plan design, and the figures change annually. Confirm current amounts and consult a qualified advisor before acting.
Frequently Asked Questions
What is ACA compliance?
ACA compliance refers to an employer’s obligations under the Affordable Care Act, principally the employer shared responsibility provisions and the associated IRS reporting. For businesses that qualify as Applicable Large Employers, it means offering minimum essential coverage that is affordable and provides minimum value to at least 95 percent of full-time employees and their dependents, and filing Forms 1094-C and 1095-C with the IRS each year. For businesses below the threshold, the employer mandate does not apply at all, and reporting is required only in limited circumstances.
Who has to comply with the ACA employer mandate?
Only Applicable Large Employers. An ALE is an employer that averaged at least 50 full-time employees, including full-time equivalents, during the preceding calendar year. Businesses under that threshold are not ALEs and have no obligation to offer health coverage under the ACA. This is the single most important fact for a small business reading about ACA compliance, and most guides bury it beneath pages of requirements that do not apply to the reader.
How do you calculate full-time equivalent employees for the ACA?
For each month of the prior calendar year, count employees averaging 30 or more hours per week or 130 or more hours per month as full-time. Then total the monthly hours of everyone who is not full-time, capping each individual at 120 hours, and divide by 120. That gives your full-time equivalent count. Add the two figures for each month, then average the twelve monthly totals. If the average is 50 or more, you are an ALE for the current year.
What is ACA compliance for HR?
In practice, the HR function owns four things: tracking hours accurately enough to run the FTE calculation and identify full-time employees, applying a measurement method to determine who is eligible for an offer of coverage, documenting the offers made and declined, and producing the data needed for Forms 1094-C and 1095-C. At a small business without an HR department, these tasks fall to the owner or an operations lead, and the hours tracking piece is usually where things break down first.
Do small businesses have to report under the ACA?
Usually not, with one important exception. A business under 50 full-time equivalents has no employer mandate obligation and generally no ACA filing duty, because a fully insured group plan is reported by the insurance carrier. However, a small employer that self-insures, uses a level-funded plan, or offers an individual coverage HRA is treated as the coverage provider and must file Forms 1094-B and 1095-B. This catches employers who chose those arrangements expecting less administration.
What are the ACA reporting deadlines?
For the 2025 tax year, Forms 1095-C had to be furnished to employees, or the alternative website notice posted, by March 2, 2026. Electronic filing of Forms 1094-C and 1095-C with the IRS was due March 31, 2026. Paper filing, permitted only for employers filing fewer than 10 information returns, was due March 2, 2026. These dates shift slightly each year, so confirm the current cycle before relying on them.
What are the ACA employer mandate penalties?
There are two, both indexed annually. The section 4980H(a) penalty applies when an ALE fails to offer minimum essential coverage to at least 95 percent of full-time employees and at least one receives a premium tax credit; for 2026 it is $3,340 per full-time employee annually, less the first 30 employees. The section 4980H(b) penalty applies when coverage is offered but is unaffordable or lacks minimum value; for 2026 it is $5,010 per employee who receives a subsidy. Both figures come from IRS Rev. Proc. 2025-26 and rose from $2,900 and $4,350 in 2025.
What is the ACA affordability percentage for 2026?
9.96 percent, set by IRS Rev. Proc. 2025-25 issued in July 2025. This is up from 9.02 percent for 2025 and is the highest the percentage has been since the requirement took effect. It means an employee’s required contribution for the lowest-cost self-only plan that provides minimum value cannot exceed 9.96 percent of their household income, or an approved safe harbor substitute for income. The increase allows employers to charge somewhat more while still meeting the test.
What are the ACA affordability safe harbors?
Because employers do not know an employee’s household income, the IRS permits three substitutes. The Form W-2 safe harbor uses the employee’s W-2 Box 1 wages from the same employer. The rate of pay safe harbor uses hourly rate multiplied by 130 hours per month, or monthly salary for salaried employees. The federal poverty line safe harbor uses the applicable FPL figure, which produces a single dollar amount that works for everyone and is the simplest option to administer. An employer can use different safe harbors for different reasonable categories of employees.
What is minimum value under the ACA?
A plan provides minimum value if it covers at least 60 percent of the total allowed cost of benefits expected to be incurred under the plan, and provides substantial coverage of inpatient hospital services and physician services. Minimum value is a separate test from affordability, and a plan must satisfy both to shield an employer from the section 4980H(b) penalty. Whether a plan meets minimum value is determined actuarially and is normally confirmed by the carrier or plan administrator rather than calculated by the employer.
What is the difference between Form 1095-B and Form 1095-C?
Form 1095-C is filed by Applicable Large Employers and reports the offer of coverage made to each full-time employee, month by month. Form 1095-B reports actual enrollment in minimum essential coverage and is filed by the coverage provider, which is the insurance carrier for a fully insured plan or the employer itself for a self-insured plan. A small employer that self-insures files 1095-B forms with a 1094-B transmittal. An ALE with a self-insured plan reports both the offer and the enrollment on the 1095-C.
Can employers still be penalized if they never received a notice?
The IRS initiates the process by sending Letter 226-J, which sets out the proposed employer shared responsibility payment and the full-time employees who triggered it. Employers respond using the enclosed form, and recent legislation extended the response window to 90 days. Ignoring the letter is what turns a proposed assessment into a final one, so the practical advice is to respond within the window even if you believe the assessment is wrong, since many are based on reporting errors rather than actual failures to offer coverage.