ACA Compliance: What Employers Need to Know
ACA compliance cannot be just a once-a-year filing exercise.
For Applicable Large Employers (ALEs), staying compliant means identifying the right employees, offering the right coverage at the right time, making sure that coverage meets affordability and minimum value standards, and maintaining accurate records to prove it. Then, yes, you still have to report it all correctly to the IRS.
That is what makes ACA compliance deceptively difficult. No single requirement is necessarily overwhelming. The challenge is getting eligibility, employee hours, coverage offers, affordability, payroll data, benefits data, ACA coding, and reporting to line up month after month.
A mistake made in February may not become visible until the following year, when a Form 1095-C is generated — or later, when an IRS penalty letter arrives.
So, what does ACA compliance actually require? Who needs to worry about it? And how do you build a process that doesn’t depend on a year-end scramble?
This article shares what employers need to know.
| ACA COMPLIANCE RELIED ON BY 1 IN 4 EMPLOYERS Selerix combines year-round ACA technology with experienced compliance specialists to help employers track eligibility, validate data, prepare forms, file with the IRS, and respond when something goes wrong. Talk to a Selerix ACA Expert |
What Is ACA Compliance?
For employers, ACA compliance means meeting both the Affordable Care Act’s coverage obligations and its reporting obligations.
Applicable Large Employers generally must offer minimum essential coverage to at least 95% of their full-time employees and their dependents. That coverage must be affordable to the employee and provide minimum value. ALEs must also document and report their offers of coverage to employees and the IRS, primarily through Forms 1094-C and 1095-C.
Those are the two halves of ACA compliance:
- The coverage obligation: Did you offer the right employees qualifying coverage at the right cost?
- The reporting obligation: Can you accurately demonstrate what happened for every employee, every month?
That second part matters because ACA compliance isn’t based on what an employer intended to do. It is based on what actually happened — and what the employer can document.
That is why the hardest ACA problems often begin in ordinary HR and payroll activity long before filing season: an employee works more hours than expected, an eligibility change isn’t reflected across systems, an affordability calculation uses the wrong pay information, or an acquisition adds employees under another EIN.
By year-end, those grow from data problems into ACA reporting problems.
Who Has to Comply? Start With Applicable Large Employer Status
The employer shared responsibility provisions apply to Applicable Large Employers, generally organizations that averaged at least 50 full-time employees, including full-time-equivalent employees, during the previous calendar year.
That “including full-time equivalents” part catches employers surprisingly often.
Under the ACA, an employee generally counts as full-time if they average at least 30 hours of service per week or 130 hours per month. For ALE calculations, employers also combine hours worked by employees who are not full-time, capped at 120 hours per employee per month, and divide those hours by 120 to determine the number of full-time equivalents.
A Simple ALE Example
Imagine an employer has: 30 full-time employees plus 30 part-time employees averaging 60 hours per month.
Those part-time employees generate: 30 × 60 hours = 1,800 hours, which divided by 120 becomes 15 full-time equivalents.
Add those 15 FTEs to the 30 actual full-time employees: 30 + 15 = 45
If that workforce pattern holds across the year, the employer would fall below the 50-employee ALE threshold. But add a few more workers, increase part-time hours, or acquire another business, and that answer can change quickly.
If your organization is near the threshold, use the Selerix ALE calculator to run your own numbers rather than relying on headcount alone.
Related Companies Count, Too
Organizations also need to look beyond individual EINs.
To determine ALE status, employers treated as a single employer under the controlled-group and affiliated-service-group rules of Internal Revenue Code Section 414 are generally aggregated. That means several individually smaller companies under common ownership can collectively become an ALE even if none reaches 50 employees alone.
Once ALE status is established for the group, however, ACA reporting and potential employer shared responsibility payments are generally handled at the individual ALE-member level.
What About Seasonal Workers?
There is also a limited seasonal-worker exception.
An employer may avoid ALE status if its workforce exceeds 50 full-time employees, including FTEs, for 120 days or fewer during the year and the employees above the 50-worker threshold during that period are seasonal workers.
That is different from the ACA rules governing how a seasonal employee may be measured for full-time status, which is one reason workforce classification can get messy fast.
Employers with variable-hour, seasonal, temporary, or other nontraditional populations should take extra care with classification. Our guides to full-time, part-time, and temporary employees under the ACA and calculating employee hours under the ACA go deeper into those rules.
The Employer Mandate: The Three Tests Your Coverage Must Pass
Being an ALE does not mean you simply have to “offer health insurance.” It’s a bit more complex than that.
The employer mandate sets three important standards.
1. The 95% Offer Test
An ALE generally needs to offer minimum essential coverage to at least 95% of its full-time employees and their dependents to avoid potential liability under Section 4980H(a). For this purpose, dependents generally means children through the end of the month in which they turn 26; spouses do not count as dependents under the employer mandate.
And again, “full-time” is an ACA definition, not necessarily whatever your organization happens to call a full-time worker internally.
The ACA generally considers an employee full-time at an average of 30 hours of service per week or 130 hours per month. Employers can use the monthly measurement method or, where applicable, the look-back measurement method to determine full-time status.
That makes accurate hour tracking especially important for variable-hour populations. Missing the 95% threshold is also considerably more dangerous than overlooking one isolated employee, because the potential Section 4980H(a) assessment is calculated across nearly the entire full-time workforce if at least one full-time employee receives a Marketplace premium tax credit.
We’ll come back to that math.
2. The Affordability Test
Offering coverage is not enough. The employee’s required contribution for qualifying self-only coverage must also meet the ACA’s affordability standard.
The affordability percentage changes annually.
For plan years beginning in 2026, the threshold is 9.96%. For plan years beginning in 2027, it rises to 10.22%. The actual statutory affordability test is based on household income — something employers generally don’t know.
Fortunately, the ACA provides three employer affordability safe harbors based on information employers can actually access:
- Form W-2 wages
- Rate of pay
- Federal poverty line
When used correctly, these safe harbors allow employers to demonstrate affordability without knowing an employee’s total household income.
The right method depends on your workforce and compensation structure. Our 2027 ACA affordability guide explains the new percentage, the three safe harbors, and how the calculations work.
And remember, check affordability before the plan year starts, not while generating 1095-Cs.
3. The Minimum Value Test
Finally, employer coverage must provide minimum value.
In general, a plan meets the ACA minimum value standard if it is designed to cover at least 60% of the total allowed cost of benefits expected under the plan and satisfies requirements around substantial coverage of inpatient hospitalization and physician services.
For many employers offering traditional comprehensive group medical coverage, minimum value is not the requirement creating the most day-to-day administrative work.
But it remains an essential part of the employer mandate. Coverage that is offered and affordable but does not provide minimum value can still expose an employer to a Section 4980H(b) assessment if an affected full-time employee qualifies for a Marketplace premium tax credit.
Put the three tests together, and the basic employer-mandate question becomes: Did we offer qualifying coverage to enough full-time employees, at an affordable employee cost, and did that coverage provide minimum value?
If yes, you still have one more job. You have to prove it.
ACA Reporting Requirements: Proving Compliance to the IRS
ACA reporting turns an entire year of workforce and benefits activity into a set of forms.
ALE members generally use Form 1094-C to report employer-level information and transmit their Forms 1095-C. Form 1095-C documents the coverage offered to individual full-time employees month by month, including the type of offer, employee contribution information where required, and applicable ACA reporting codes.
Those little codes on Lines 14 and 16 carry a remarkable amount of weight. If you need a refresher on how they work, our ACA Codes Cheat Sheet walks through them in detail.
Most ALEs should also expect to file electronically. Beginning with tax year 2023, employers have generally been required to e-file when they must submit 10 or more information returns in aggregate, including information returns such as W-2s—which means the threshold captures most organizations subject to ACA reporting. ACA returns are electronically submitted through the IRS AIR system.
Reporting deadlines generally fall in late February for eligible paper filers and March 31 for electronic filings, subject to weekend and holiday adjustments. Employee-statement requirements have also changed under recent legislation, including the option to use a furnish-on-request process when all applicable requirements are met.
If reporting season is approaching, our guide to preparing accurate Forms 1094-C and 1095-C covers the year-end process in more detail.
But the most important reporting lesson is this: You cannot fix twelve months of bad data with a really good filing process. Accurate reporting depends on accurate information all year long.
What Non-Compliance Costs: ACA Penalties at a Glance
ACA penalties can get large very quickly because the employer shared responsibility provisions include two different potential assessments.
They’re usually called the 4980H(a) and 4980H(b) penalties.
| Penalty | What can trigger it | 2026 annual amount | 2027 annual amount |
| 4980H(a) | Employer fails the 95% offer test and at least one full-time employee receives a Marketplace premium tax credit | $3,340 per full-time employee, after the first 30 | $3,780 per full-time employee, after the first 30 |
| 4980H(b) | Employer meets the 95% threshold but an affected full-time employee receives a premium tax credit because coverage was not offered, affordable, or minimum value | $5,010 per affected full-time employee | $5,670 per affected full-time employee |
The IRS adjusts both amounts annually.
How Fast Can the 4980H(a) Penalty Grow?
Consider an ALE with 300 full-time employees that fails to offer minimum essential coverage to at least 95% of them for the full year. If at least one full-time employee receives a Marketplace premium tax credit, the 2026 annualized calculation would be:
300 full-time employees − 30 = 270
270 × $3,340 = $901,800
That is nearly $902,000 in potential employer shared responsibility payments.
And the larger workforce-wide assessment can sometimes stem from what initially looks like a simple reporting or eligibility problem.
As Ashley Pope, Selerix Director of ACA Services, put it during our ACA Fundamentals webinar: “Most ACA penalties come from preventable errors.”
That is an important distinction. An IRS notice does not automatically mean the proposed assessment is correct. Reporting errors can make a compliant employer look noncompliant. A missing indicator, incorrect employee status, a coding mistake, an affordability issue, or mismatched data sources can all contribute to an assessment.
If you receive one, don’t simply pay it because the envelope says IRS. Start by understanding what ACA penalty letters mean and how to respond. And if you already have a proposed assessment in hand, Selerix also offers ACA penalty review and reduction support.
How to Stay ACA Compliant: 7 Strategies That Actually Work
Here’s some bad news. There is no clever filing trick that replaces good year-round ACA operations. BUT! You can build consistent habits that make compliance easier year-round.
The employers that make ACA compliance predictable tend to do seven things consistently.
1. Audit Before There’s a Problem
Check your ACA data throughout the year instead of waiting until forms are populated.
Review employee classifications, coverage offers, affordability, missing identifiers, employer data, and unusual reporting patterns. Early detection gives you the chance to fix the underlying issue while there is still time to do something about it.
2. Continuously Track Status and Hours
Variable-hour employees do not politely wait until December to become ACA problems.
Track hours of service and measurement periods as they happen. Pay particular attention to new hires, employees moving between part-time and full-time schedules, seasonal populations, leaves, rehires, and employees whose hours fluctuate.
3. Use Technology With ACA Validation Built In
Spreadsheets can calculate things. They cannot automatically know when a code combination is inconsistent, an affordability test has failed, an employee crosses a threshold, or an IRS reporting rule has changed.
Set aside the old spreadsheets and use ACA-specific technology to automate much of that monitoring and surface exceptions while they are still actionable.
4. Track Benchmarks and Deadlines
Affordability percentages, penalty amounts, reporting requirements, and filing procedures can change. Build an annual ACA calendar covering plan-year affordability review, measurement periods, eligibility changes, data audits, employee information validation, furnishing requirements, and IRS filing.
Our mid-year ACA compliance checklist is a useful checkpoint for making sure the work is progressing before reporting season arrives.
5. Educate Employees
ACA compliance is an employer responsibility, but employees are part of the data flow. They need to know when coverage is available, when they must act, how eligibility works, and why HR may be asking them to verify information such as names or Social Security numbers.
Clear employee communication reduces confusion and can help surface bad data before it reaches an IRS form.
6. Get HR, Payroll, Benefits, and IT Working From the Same Story
Some of the most common ACA problems happen when every system is technically correct — according to its own data. Payroll says one thing. Benefits says another. HR has a third employment date. The ACA platform receives pieces of all three.
That is why ACA compliance is fundamentally also a data-governance problem. We explore that more deeply in ACA Compliance Isn’t Just a Filing Task — It’s a Data Problem.
7. Integrate and Verify Before You File
Automation is valuable. Blind automation is not.
Bring eligibility, payroll, coverage, demographic, and reporting data together — then reconcile it. Your final pre-submission review should confirm that what the forms say matches what actually happened throughout the year.
For an expanded walkthrough of all seven areas, see our 7 Strategies for Better ACA Compliance.
Five Common ACA Compliance Mistakes
Even mature HR teams can fall into the same traps.
- Misclassifying variable-hour or seasonal employees. Internal job titles do not determine ACA full-time status. Hours of service do.
- Confusing affordability with household income. Household income drives the underlying statutory test, but employers generally use the W-2, rate-of-pay, or federal-poverty-line safe harbors because they do not know an employee’s household income.
- Ignoring TIN mismatches. A name/SSN mismatch doesn’t become less important because the filing was accepted with errors. Investigate it, correct what you can, and document your efforts.
- Treating ACA as a January project. By January, the coverage year you are reporting has already happened. If employees were misclassified or coverage was unaffordable, filing season is when you discover the problem — not when you can undo it.
- Ignoring IRS letters. Review a proposed penalty promptly. Many ACA assessments are generated from information available to the IRS and may reflect underlying reporting problems. Understanding what triggers a Letter 226-J can help you recognize how those assessments arise.
There’s a common thread running through all five of these mistakes, did you notice? ACA compliance gets expensive when small problems are allowed to age.
How ACA Compliance Software Changes the Work
Could an employer manage ACA compliance manually? Technically, yes.
But consider what that means at scale. Someone needs to continuously track hours and full-time status. Someone needs to determine eligibility. Someone needs to monitor affordability. Someone needs to translate month-by-month employee histories into the correct 1095-C codes. Someone needs to validate names and TINs, reconcile data across systems, produce forms, manage employee statements, transmit files through AIR, review IRS acknowledgments, make corrections, maintain records, and respond when the IRS has questions.
Those tasks must stay accurate as people are hired, terminated, promoted, transferred, rehired, moved between entities, placed on leave, and coverage changes.
This is where purpose-built ACA technology changes the work.
A strong ACA compliance system can automate or support:
- Hours and eligibility tracking. Identify full-time status and continuously monitor variable-hour employees.
- Affordability testing. Apply affordability rules and safe harbors before a failed offer becomes a penalty risk.
- ACA code determination. Translate employee eligibility, coverage offers, elections, and status into the appropriate Form 1095-C reporting.
- Data validation. Find missing or inconsistent information before filing.
- Form production and e-filing. Generate Forms 1094-C and 1095-C and transmit them electronically through the IRS AIR system.
- Correction management. Identify and resolve IRS errors, including TIN mismatches and corrected filings.
- Audit history and defense. Preserve the records needed to understand what happened if a notice arrives years later.
Selerix combines those capabilities with ACA specialists who can step in when an easy case becomes complicated.
Scale and experience also matter a lot. Our current Selerix ACA platform supports more than 19 million employees, 40,000 companies, and 7.8 million forms produced, with $650 million+ in IRS penalties mitigated since 2017.
The Best ACA Filing Season Is a Boring One
ACA compliance shouldn’t become an emergency every January. By the time Forms 1095-C are populated, the most important compliance work should already be done.
- You should know who your full-time employees were.
- You should know whether coverage was offered.
- You should know whether it was affordable.
- Your HR, payroll, eligibility, and benefits data should agree.
And when reporting begins, your job should be to confirm the record — not reconstruct the year. That is what good year-round ACA compliance looks like.
Selerix helps employers move from reactive reporting to continuous compliance, with technology that tracks the details and experienced ACA specialists who know what to do when the details don’t line up.
Make ACA Compliance Quieter
From employee eligibility and affordability through 1095-C coding, IRS filing, corrections, and penalty support, Selerix helps keep the ACA lifecycle connected.
Talk to a Selerix ACA expert and see what year-round compliance can look like.
Not ready for a conversation yet? Start with the Mid-Year ACA Compliance Checklist and see where your current process stands.
