Stop us if this sounds familiar: Say it’s the end of the year. You, an Applicable Large Employer (ALE), finish your open enrollment, catch your breath, and then realize that ACA reporting season is already rounding the corner.

Maybe that’s cool. But maybe panic sets in. The data is scattered, the deadlines are firm, and the people responsible for filing are all the same ones who just ran a full benefits cycle. You’re tired, but you have to start scrambling anyway. 

ACA year-end reporting doesn’t have to be an anxious fire drill— but it sure will be if you weren’t able to lay the groundwork earlier in the year. 

This guide covers what the process actually requires and what a practical preparation timeline looks like from data gathering through submission.

If you want the short version, our ACA year-end compliance checklist is a good starting point. If you want to understand what’s behind it and why each step matters, keep reading.

What Is ACA Compliance Reporting and Who Has to Do It?

ACA compliance reporting is the annual process by which Applicable Large Employers demonstrate to the IRS that they met their obligations under the Affordable Care Act’s employer mandate. It’s how the IRS verifies coverage, flags potential penalties, and enforces the law. It is not a formality.

For most ALEs, this means two things every year: distributing Form 1095-C to employees and filing Forms 1094-C and 1095-C with the IRS. Both have firm deadlines, and errors in either can trigger penalty letters, sometimes years after the original filing.

ACA Reporting Requirements for Large Employers

Under the ACA employer mandate, an employer is an Applicable Large Employer if it employed an average of 50 or more full-time equivalent employees in the prior calendar year. That threshold includes both full-time employees (30+ hours per week) and a calculated share of part-time employees.

ALEs are required to:

• Offer minimum essential coverage to at least 95% of full-time employees and their dependents
• Ensure that coverage meets minimum value and affordability standards
• Track monthly employee count, hours, and offer status throughout the year
•  Furnish Form 1095-C to all full-time employees
•  File Forms 1094-C and 1095-C with the IRS — electronically if filing 10 or more returns, per the IRS AIR system

The penalty structure has two components. 

• The 4980H(a) penalty is triggered when an ALE fails to offer coverage to substantially all full-time employees and at least one employee receives a premium tax credit. 
• The 4980H(b) penalty applies when coverage is offered but doesn’t meet affordability or minimum value standards. Both accumulate monthly.

Understanding ALE Status and ACA ALE Reporting Requirements

ALE status is determined by the prior year’s headcount, which means employers near the 50 FTE threshold need to track their numbers carefully year-round. Controlled group and aggregation rules can cause related entities to be treated as a single employer for ALE purposes, even when no individual entity independently meets the 50-employee threshold. This is one of the more commonly misunderstood aspects of ACA reporting, and one of the more consequential ones.

Acquisitions, divestitures, and entity changes during the year also affect ALE determination and need to be reflected accurately in your filings.

Forms Involved in ACA Form 1095-C Compliance Reporting

The two forms at the center of ACA year-end reporting:

•  Form 1095-C: The employee-level form that reports offer and coverage details for each full-time employee. Lines 14, 15, and 16 carry the codes that tell the IRS what was offered, at what cost, and under which safe harbor. This is what employees receive and what the IRS matches against individual tax returns.
• Form 1094-C: The employer-level transmittal that summarizes your ALE group and accompanies Form 1095-C in your IRS filing. It certifies your offer of coverage, identifies your ALE member designations, and carries monthly totals.

Self-Insured Plans carry an additional layer: covered individuals must be reported on Part III of Form 1095-C (or on a Form 1095-B if filing separately). This tracks who was actually enrolled — not just offered coverage — and is used for individual mandate verification in states that have one.

How ACA Tracking and Reporting Fit Together Over the Year

ACA year-end reporting is not a fourth-quarter project. It’s the output of twelve months of data collection, and the quality of your filing is largely determined by how consistently you tracked throughout the year.

How Monthly Tracking Drives ACA Year-End Reporting

Form 1095-C is a monthly document. Lines 14, 15, and 16 reflect what was offered, what it cost, and what safe harbor applies,  for each month, for each full-time employee. Every hire, termination, leave, and eligibility change needs to be captured and correctly coded when it happens.

Employers who try to reconstruct this data in November face a real problem: records are incomplete, people have left, and payroll doesn’t match benefits. The filing deadline doesn’t adjust for that.

The Role of HR, Benefits, and Payroll in ACA Tracking and Reporting

ACA reporting sits at the intersection of HR, benefits administration, and payroll: three functions that don’t always communicate as regularly as they should. Each owns a distinct piece of the data.

•  HR owns employment status, hire and termination dates, leave records, and hours of service tracking for variable-hour employees in measurement periods.
• Benefits administration owns offer documentation, enrollment records, the cost of the lowest-cost self-only minimum value plan (needed for Line 15), and dependent enrollment data for Self-Insured Plans.
• Payroll owns hours worked, compensation records, and the affordability calculations that connect employee contribution amounts to the safe harbor method in use.

When these data sources aren’t regularly reconciled, the gaps show up in Form 1095-C codes — producing entries that are technically defensible but not accurate, or worse, codes that can’t be supported if the IRS requests documentation.

Common Data Gaps That Cause ACA Reporting Issues

The gaps that cause the most trouble at year-end:

• Variable-hour employees whose measurement periods weren’t tracked consistently, leaving their full-time status uncertain
• New hires in the initial measurement period whose offer timing wasn’t documented at the point of hire
• Employees who waived coverage with no documentation of the waiver or the offer behind it
• Mid-year plan changes or eligibility changes that weren’t reflected in benefits records
• Terminated employees whose COBRA offer and election status wasn’t captured
• TIN validation errors from SSNs that were entered incorrectly or never verified
• Controlled group members tracked separately when they should have been reported under a consolidated ALE structure

Most of these are preventable with consistent processes. The ACA compliance checklist walks through the verification steps to catch them before filing.

Preparing for ACA Year-End Reporting: Your Step-by-Step Process

Work through these steps in order. They build on each other, and skipping ahead tends to create exactly the data problems that require late corrections and IRS correspondence.

Step 1: Set Your ACA Year-End Reporting Calendar and Ownership

Before touching any data, establish who owns what and when each task needs to be done. ACA reporting involves multiple systems and multiple teams, and without clear ownership, things fall through the gaps at the wrong moment.

Assign explicit responsibility for:

•       Data gathering and reconciliation — who pulls from HR, payroll, and benefits

•       Code determination and Form 1095-C preparation

•       Form 1095-C distribution to employees

•       Form 1094-C preparation and IRS submission

•       Error correction if the IRS rejects or flags the filing

Work backward from your filing deadlines. Two months of runway before the employee furnishing deadline is a reasonable minimum for most ALEs — less than that and you’re accepting meaningful risk.

Step 2: Gather and Validate Your ACA Reporting Data

Pull your full-year data from HR, payroll, and benefits systems and consolidate it. What you need:

•       Complete employee roster including all hires, terminations, and status changes

•       Monthly full-time status for every employee based on hours or classification

•       Offer of coverage documentation for each employee, with effective dates

•       Plan enrollment and waiver records

•       Lowest-cost self-only minimum value premium amount by month, for Line 15

•       Dependent enrollment data if you have a Self-Insured Plan

•       COBRA offer and election records for terminated employees

•       Verified SSNs and addresses for all employees receiving Form 1095-C.

Run TIN validation on your employee SSN data before anything else. TIN errors are the single most common cause of IRS rejection, and they’re preventable with early verification.

Step 3: Reconcile Payroll and Benefits for ACA Payroll Reporting

Payroll and benefits records rarely match out of the box. Common discrepancies include employees who appear in one system but not the other, coverage periods that don’t align with payroll deduction periods, and affordability calculations based on the wrong contribution amounts.

Reconcile at the employee level, not just at totals. Discrepancies found here are fixable before filing. After submission they require amended returns.

Step 4: Determine Form 1095-C Codes and Review Edge Cases

Lines 14, 15, and 16 carry the codes that describe your offer of coverage, its cost, and the applicable safe harbor. Getting these right requires knowing what actually happened — month by month — for each employee.

The codes that trip up most filers:

•       Line 14 code 1H (no offer) requires verifying that no offer was actually made, not just that no enrollment occurred

•       Line 16 code 2C (enrolled) should only appear when the employee was actually enrolled — not as a default when you’re unsure

•       Line 16 affordability safe harbors (2F, 2G, 2H) require documentation of which method you’re using and confirmation it was applied consistently

•       New hire initial measurement periods require specific codes during the waiting window that differ from standard offer codes

Review individually: employees on extended leave, anyone who moved between part-time and full-time status mid-year, and any acquisitions or divestitures that changed your ALE composition.

Step 5: Choose Your ACA Reporting Method and Platform

ALEs filing 10 or more returns must file electronically through the IRS AIR system — either via a direct connection or a third-party transmitter. If you haven’t confirmed your filing method, do it now. Selerix ACA software handles direct transmission and code determination, but onboarding a new platform in December is harder than it sounds. Confirm early.

If you’re using an existing platform, verify it’s been updated for the current reporting year and that your data import process is tested before you need it.

Step 6: Run Test Files and Pre-Filing Quality Checks

Before submitting to the IRS, run your data through a quality check:

•       Missing or invalid SSNs

•       Code combinations that don’t exist or aren’t valid together

•       Months with no code populated for active employees

•       Line 15 amounts outside reasonable ranges

•       Form 1094-C totals that don’t match the sum of your Form 1095-C records

If your platform supports test file submission to the IRS AIR system, use it. Errors caught in a test file cost nothing to fix. After submission, they require correction filings and IRS processing time.

Key ACA Year-End Reporting Deadlines and Penalties

These deadlines are fixed. Extensions are available in limited circumstances and must be requested proactively.

Deadline	Date / Notes
Furnish Form 1095-C to employees	March 2, 2026 (for 2025 tax year); confirm current year deadline
File Form 1094-C and Form 1095-C electronically with IRS	March 31, 2026 (for 2025 tax year); confirm current year deadline
Paper filing deadline (if under 10 returns)	March 2, 2026 (for 2025 tax year); confirm current year deadline
TIN validation / error correction window	Ongoing — address prior-year errors before current-year filing

Note: Deadlines listed reflect the 2025 reporting year. Confirm current-year deadlines before publishing. The ACA Resource Studio publishes updated guidance as the IRS releases it.

Penalty Type	Amount (approximate; verify current year)
Failure to furnish correct Form 1095-C to employee	Up to $340 per return; intentional disregard (2025)
Failure to file correct Forms 1094-C/1095-C with IRS	Up to $340 per return
4980H(a) — failure to offer coverage to 95% of FTEs	$2,900 per full-time employee (2025) minus first 30
4980H(b) — coverage not affordable or minimum value	$4,350 per full-time employee receiving premium tax credit (2024)

Penalty amounts adjust annually. Confirm current-year figures with your ACA compliance advisor or the IRS ACA employer provisions page. The figures above are directional; they don’t include the administrative cost of IRS correspondence and amended filings.

Avoiding Common ACA Reporting Pitfalls

The mistakes that appear most often in ACA filings — and the habits that prevent them:

• Treating ACA reporting as a year-end project. The data is generated all year. Trying to reconstruct it in Q4 is the root cause of most filing errors.
• Defaulting to 1H/2A codes without verification. “No offer / not applicable” codes are only correct when the employee actually wasn’t offered coverage that month. Using them as defaults when you’re unsure creates inaccurate filings.
• Ignoring TIN validation until the last minute. The IRS sends B-Notices for mismatched SSNs, and resolving them requires employee outreach — which takes time you won’t have in February.
• Assuming payroll handles ACA. Payroll systems track hours and compensation. They typically don’t determine offer codes or manage the ALE structure logic required for accurate Form 1095-C coding.
• Not documenting affordability safe harbor elections. The IRS can ask you to demonstrate which safe harbor method you used. “We used the W-2 Safe Harbor” is not sufficient without the underlying documentation.
• Skipping the reconciliation step. The Form 1094-C totals must reconcile with the Form 1095-C. A mismatch triggers IRS correspondence almost automatically.

The ACA compliance ebook covers these scenarios in more detail, including edge cases and documentation practices.

When Payroll Is Not Enough for ACA Compliance Reporting

This is worth addressing directly, because many employers discover it too late: payroll systems are not ACA reporting systems.

Payroll platforms are built to process compensation accurately and on time. Most track hours of service reasonably well. But the logic required for accurate Form 1095-C coding is different from what payroll was designed to handle.

Payroll systems typically don’t:

• Determine Form 1095-C offer codes based on offer status rather than enrollment
• Track dependent enrollment for Self-Insured Plan reporting
• Handle controlled group and aggregated ALE calculations
• Manage initial and standard measurement periods for variable-hour employees
• Support TIN validation and IRS AIR electronic filing
• Generate 1094-C transmittal logic with ALE member certifications

Payroll data is an essential input into ACA reporting — it just needs to flow into a purpose-built solution that can interpret it correctly. Selerix ACA software is built specifically for the code determination, measurement period tracking, and IRS filing logic that payroll platforms weren’t designed for.

How Selerix and SyncStream Support ACA Reporting Compliance for Employers

At Selerix, ACA compliance is built into the platform’s year-round workflow rather than handled separately at filing time. Selerix BenSelect tracks offer status, enrollment data, and ALE structure as part of ongoing benefits administration — which means the data needed for year-end reporting is captured continuously.

For employers with more complex needs — controlled groups, multiple EINs, variable-hour tracking, or prior-year corrections — Selerix provides year-round specialist support alongside purpose-built reporting tools, and handles code determination, TIN validation, IRS AIR filing, and state mandate reporting.

Learn more about how Selerix supports ACA compliance, or explore the ACA Resource Studio for updated guidance and tools.

FAQs on ACA Year-End Reporting and Forms 1094/1095  

Do small employers ever have to worry about ACA year-end reporting?

Generally no — the ACA employer mandate and its reporting requirements apply only to ALEs with 50 or more full-time equivalent employees in the prior year. That said, small employers who sponsor Self-Insured health plans have separate reporting obligations under Section 6055 and must file Forms 1094-B and 1095-B. If your headcount is near the 50 FTE threshold, track it carefully — ALE status is determined annually.

If I use a PEO or fully insured plan, do I still have ACA reporting responsibilities?

It depends on the arrangement. In a PEO relationship, reporting responsibilities vary based on whether the PEO is a Certified PEO and how the employment relationship is structured. With a fully insured plan, the employer still has Section 6056 reporting obligations for the offer of coverage even though the insurance carrier handles Section 6055 coverage reporting. Don’t assume your PEO or carrier is handling everything without confirming it in writing.

How long do I need to keep ACA reporting records?

The IRS hasn’t specified a formal retention period, but given that penalty assessments can arrive years after a filing and the statute of limitations can extend to six years, most compliance advisors recommend retaining ACA records for at least that long. This includes offer documentation, enrollment records, hours tracking data, affordability calculations, and copies of filed forms.

How does ACA year-end reporting interact with state individual mandate reporting?

Several states — including California, Massachusetts, New Jersey, Rhode Island, and Washington D.C. — have their own individual mandates and require employers to report coverage information to state tax authorities separately from the IRS filing. Deadlines and form requirements vary by state. Selerix supports state-level mandate reporting alongside federal ACA filing.

Can ACA payroll reports replace a dedicated ACA reporting solution?

No — and it’s a costly assumption to get wrong. Payroll reports capture hours worked and compensation. They can’t determine correct Form 1095-C offer codes, manage measurement periods for variable-hour employees, or handle the ALE structure logic required for accurate filings. Payroll data is an essential input; the reporting itself requires a purpose-built solution.

Ready to get ACA reporting under control year-round, not just at filing time? Talk to a Selerix ACA expert or download the ACA compliance ebook.