What Is ACA Affordability and Why It Matters in 2026?
Under the Affordable Care Act, an employer-sponsored health plan is considered affordable if the employee’s required contribution for self-only coverage does not exceed a specific percentage of their household income for the year. For 2026, the IRS publishes the exact affordability threshold annually — employers should confirm the current-year percentage directly on IRS.gov before running their calculations, as it adjusts each plan year. Businesses approaching or already over 50 full-time equivalent employees (FTEs) need to get this right: failure to offer an affordable plan can trigger significant Employer Shared Responsibility Payments (ESRPs) under IRC Section 4980H(b).
Affordable Care Act compliance is not just a large-company problem. If your headcount is anywhere near the 50-FTE threshold, you are likely an Applicable Large Employer (ALE) or will be soon — and ALE status means the affordability rules apply to you. This guide walks through exactly how the affordability test works, the three IRS-approved safe harbors you can use, and what happens if a plan fails the test.
How Does the ACA Affordability Test Work?
The affordability test compares what an employee pays for the lowest-cost, self-only plan you offer to that employee’s household income. Because employers almost never know an employee’s actual household income, the IRS created three safe harbors — calculation methods that, if used correctly, protect employers from ESRP exposure even if an employee’s actual household income turns out to be different.
Here is the core logic: if the employee’s required monthly premium contribution for self-only minimum essential coverage (MEC) does not exceed the IRS threshold percentage of the applicable income figure under the safe harbor you choose, your plan is deemed affordable for that employee. The test applies to the lowest-cost self-only option you make available — not the plan the employee actually enrolls in.
Why the Lowest-Cost Plan Is the Benchmark
Many employers offer tiered plan options — bronze, silver, gold. For affordability purposes, what matters is whether the cheapest self-only MEC plan you offer passes the test. If an employee can access an affordable option but chooses a more expensive tier, you are still compliant for that employee. This means your benefit design strategy and your affordable-tier pricing are directly linked to your ACA exposure.
Wondering if a PEO could get your team better benefits for less? Run the numbers yourself — our free calculator shows you what companies your size are actually paying.
The Three ACA Safe Harbors Every Employer Should Know
Because employers cannot realistically verify each employee’s household income, the IRS established three safe harbors for 2026. Each one uses a different income proxy, and each has practical trade-offs. You can use different safe harbors for different classes of employees, as long as you apply each one consistently within that class.
1. The W-2 Safe Harbor
Under the W-2 safe harbor, a plan is affordable if the employee’s required contribution for self-only coverage does not exceed the IRS threshold percentage of the employee’s W-2 wages (Box 1) from the prior calendar year. This is the most straightforward method for salaried employees with predictable, stable pay. However, it creates a potential timing mismatch: you need to set contribution amounts for the upcoming plan year before the W-2 is finalized. Employers typically use the prior year’s W-2 as a proxy and adjust plan pricing accordingly. This safe harbor can also be tricky for new hires or employees whose hours vary significantly, since their W-2 wages may not yet reflect a full year of earnings.
2. The Rate of Pay Safe Harbor
The rate of pay safe harbor is generally the most employer-friendly option for hourly workers. For hourly employees, multiply the employee’s hourly rate as of the first day of the plan year by 130 hours (the IRS-defined full-time hours threshold per month) to get a monthly income proxy. For salaried employees, use their monthly salary. If the required contribution does not exceed the IRS percentage of that monthly figure, the plan is affordable under this safe harbor. The key advantage: you can calculate affordability before the year begins, because you are using current rates rather than looking back at W-2 data. The limitation is that it cannot be used if an employee’s hourly rate dropped during the year — you must use the lowest rate in that scenario.
3. The Federal Poverty Line (FPL) Safe Harbor
The FPL safe harbor is the simplest to administer and the one most likely to result in a passing test — but it may require the lowest employee contribution, meaning higher employer cost. Under this method, a plan is affordable if the required contribution for self-only coverage does not exceed the IRS threshold percentage of the Federal Poverty Line for a single individual (published annually by HHS). Because the FPL is a fixed, publicly available number, every employee is treated the same regardless of their individual wages. This safe harbor works especially well for employers with a large hourly workforce, high turnover, or complex payroll structures where tracking individual rates is administratively difficult. Check the current FPL figures at HHS.gov each plan year.
| Safe Harbor | Income Proxy Used | Best For | Main Watch-Out |
|---|---|---|---|
| W-2 | Prior-year Box 1 wages | Salaried, full-year employees | Timing mismatch; tricky for new hires |
| Rate of Pay | Hourly rate × 130 hrs or monthly salary | Hourly workers, predictable scheduling | Cannot use if rate dropped mid-year |
| Federal Poverty Line | FPL for a single person | High-turnover or complex workforces | May require lowest employee contribution |
What Happens When a Health Plan Fails the Affordability Test?
When a plan fails the ACA affordability test, the consequences fall under Section 4980H(b) of the Internal Revenue Code — sometimes called the “B Penalty” or the “affordability penalty.” An employer is only exposed to this penalty if at least one full-time employee receives a premium tax credit (PTC) through a Marketplace plan. The IRS does not automatically assess the penalty — it is triggered by employee Marketplace enrollments and the subsequent IRS matching process.
How the ESRP Penalty Is Calculated
The 4980H(b) ESRP is assessed monthly, per full-time employee who actually receives a PTC through the Exchange. The penalty amount is set by the IRS and adjusted annually — confirm the current dollar figure for 2026 on IRS.gov. The key distinction from the 4980H(a) penalty (for failing to offer coverage at all) is that the (b) penalty only applies to employees who actually go to the Marketplace and receive a subsidy — not to your entire workforce. That said, even a handful of employees triggering PTC claims can result in tens of thousands of dollars in annual exposure for a mid-size employer.
The IRS Notification Process
The IRS identifies potential ESRP liability through the ACA information reporting employers file — Forms 1094-C and 1095-C. The agency matches those filings against individual tax returns where employees claimed PTCs, then issues Letter 226-J to employers with proposed ESRP assessments. Employers have a defined window to respond and dispute the proposed assessment. Accurate, timely 1094-C/1095-C filing is your first line of defense — errors or missing data make it harder to challenge an incorrect penalty notice.
How a PEO Can Take ACA Compliance Off Your Plate
For employers near or over the 50-FTE threshold, ACA tracking, safe harbor calculations, and 1094-C/1095-C reporting represent a significant administrative burden — especially if your workforce includes a mix of full-time, part-time, and variable-hour employees. This is one area where a Professional Employer Organization (PEO) delivers measurable value beyond payroll processing.
A PEO takes on co-employer responsibilities for your workforce, which typically includes managing ACA measurement periods, running affordability calculations, and filing ACA reporting on your behalf. In our experience matching hundreds of businesses through PEO Marketplace, ACA compliance administration is one of the top three reasons employers in the 40–100 FTE range decide to move to a PEO. According to NAPEO, businesses that use a PEO grow 7–9% faster and have 10–14% lower employee turnover than comparable companies that do not — and reduced compliance risk is a core driver of that outcome.
If you are evaluating PEO options, it is worth understanding how different providers handle ACA reporting as part of their service model. Some fully absorb it; others treat it as an add-on. Our guide to the best PEOs for small business breaks down what to look for. You can also review our Insperity cost comparison to see how one of the larger PEOs structures its compliance services relative to competitors.
What to Ask a PEO About ACA Before You Sign
Not all PEOs handle ACA the same way. Before committing, ask specifically: Does the PEO file 1094-C and 1095-C under their own EIN or yours? Who runs the measurement period tracking for variable-hour employees? What happens if an affordability calculation error results in a penalty — who bears that liability? The answers to these questions will tell you a lot about how serious a given provider is about ACA compliance versus treating it as a checkbox.
2026 ACA Affordability: Key Takeaways for Employers
ACA affordability in 2026 comes down to a clear framework: know your IRS threshold percentage (confirm it at IRS.gov), choose the right safe harbor for each employee class, price your lowest-cost plan accordingly, and file accurate 1094-C/1095-C reports on time. If you are managing this manually across a workforce of 50 or more employees, the administrative complexity compounds quickly — especially when you layer in variable-hour workers, seasonal staff, and mid-year new hires.
Whether you handle ACA compliance in-house or explore a PEO partnership, the math matters. Use our free PEO cost calculator to see what employers your size are actually paying for HR and benefits administration — including ACA compliance services — so you have a real benchmark before making any decisions.
Ready to stop managing ACA compliance manually?
Book a free 15-minute call with a PEO Marketplace advisor. We will match you with vetted providers that handle ACA tracking, safe harbor calculations, and 1095-C filing — at no cost to you.
Not ready to book a call? Get a free Benefits Benchmark Report for your industry — we will email you a breakdown of what companies your size are paying for HR, benefits, and workers comp so you can compare on your own timeline.
Frequently Asked Questions About ACA Affordability
What is the ACA affordability percentage for 2026?
The IRS adjusts the ACA affordability percentage annually and publishes it in a revenue procedure each fall. Employers should confirm the exact 2026 figure directly on IRS.gov before calculating employee contributions, as guessing or using a prior-year number can result in a plan that technically fails the test.
Does the affordability test apply to dependent or family coverage?
No — the ACA affordability test applies only to the employee’s required contribution for self-only coverage, not to the cost of adding dependents or a spouse. However, starting in 2025, the “family glitch” fix from the IRS means dependents’ eligibility for Marketplace tax credits is also affected by the affordability of family-tier coverage, which is a separate but related compliance consideration.
Can I use different safe harbors for different groups of employees?
Yes, employers may use different safe harbors for different employee classifications — for example, the rate of pay safe harbor for hourly workers and the W-2 safe harbor for salaried employees. The IRS requires that each safe harbor be applied consistently to all employees within a reasonable classification, so document your methodology clearly for each group.
What is Form 1095-C and who needs to file it?
Form 1095-C is the ACA information return that Applicable Large Employers must furnish to full-time employees and file with the IRS alongside Form 1094-C. It reports whether coverage was offered, the employee’s required contribution, and the safe harbor code used — this is the data the IRS uses to identify potential ESRP liability. ALEs must file these forms annually, with deadlines set by the IRS for each reporting year.
Does a PEO file ACA forms on my behalf?
Many PEOs do file Forms 1094-C and 1095-C as part of their co-employment service, though the specific arrangement varies by provider — some file under their own EIN, others file under the client employer’s EIN. Before selecting a PEO, confirm exactly who bears filing responsibility and what liability the PEO accepts if an error leads to a proposed ESRP assessment. Our comparison of leading PEOs covers how different providers approach this.
