The Hidden ACA Compliance Mistakes Quietly Costing California Employers Thousands

Most California employers with 10 to 50 employees are one or two filings away from a penalty letter they never expected. Here are the traps and how to close them.

Most owners of small and mid sized companies in California do not lose sleep over benefits compliance. They lose sleep over payroll, cash flow, customers, and hiring. Compliance feels like one of those background things that the broker or the payroll company is presumably handling, until the day a letter shows up from the IRS or the Department of Labor and suddenly it is the only thing anyone is thinking about.

We have been writing group benefits for California employers since 1995, and the same handful of compliance mistakes come up over and over. Almost every one of them is preventable. Almost every one of them is invisible until it is not. And almost every one of them lands hardest on companies in the 10 to 50 employee range, because that is the size where the rules get more serious but the in house HR support usually does not yet exist.

Mistake 1. Not knowing whether you are an Applicable Large Employer

Under the ACA, an Applicable Large Employer, or ALE, is generally any company that averaged 50 or more full time equivalent employees during the prior calendar year. Part time hours roll up into the FTE calculation, so a company with 35 full time staff and 25 part timers can absolutely cross the line without ever feeling like a big employer.

If you are an ALE and do not know it, you are exposed to two things. The employer shared responsibility penalty for not offering minimum essential coverage to enough of your full time employees, and the failure to file penalty for not submitting 1095 C and 1094 C forms. The first one can run more than 2,900 dollars per full time employee. The second one starts at 310 dollars per missed form and stacks fast.

Mistake 2. Filing 1095 C forms incorrectly, or not at all

Even employers who know they are ALEs routinely file 1095 C forms with the wrong codes on lines 14 and 16. The codes describe the offer of coverage and the safe harbor used for affordability. Pick the wrong one and the IRS computer reads it as if you did not offer compliant coverage, and the proposed penalty notice, called a Letter 226 J, shows up nine to fifteen months later.

California also has its own state mandate filing, which is separate from the federal one and easy to miss. Both have to be done right, and both have deadlines that do not move because you are busy.

Mistake 3. Failing the affordability test you did not know existed

For 2026, employer sponsored coverage is considered affordable only if the employee's share of the lowest cost self only plan is no more than 9.02 percent of their household income, measured using one of three safe harbors. The W 2 safe harbor is the most common, and the threshold floor keeps moving year to year.

Plenty of small employers offer what they consider a generous plan, then discover at renewal that the lowest paid full time worker is being asked to pay more than the affordability cap. That alone can trigger a per employee penalty if any of those workers go to Covered California and receive a subsidy.

Mistake 4. No Section 125 POP plan on file

If your employees pay their share of premium through pre tax payroll deduction, you are required to have a Section 125 Premium Only Plan document in place, formally adopted, and updated when rates change. A surprising number of California small employers do this through payroll without ever having the underlying plan document. If the IRS ever audits, those pre tax deductions can be reclassified as taxable wages, with interest.

Mistake 5. Treating COBRA as the carrier's problem

COBRA, and the California specific Cal COBRA for groups under 20 lives, requires specific notices on specific timelines. Initial notice when an employee joins the plan. Election notice within 14 days of a qualifying event. Notice of unavailability. Notice of early termination. The carrier does not send these for you in most cases. If you miss them, the statutory penalty is up to 110 dollars per day per affected person, plus the potential for the former employee to sue.

Mistake 6. Outdated or missing ERISA wrap document

Most welfare benefit plans are governed by ERISA, which requires a Summary Plan Description and a Plan Document. The carrier booklet by itself does not satisfy that requirement. A simple wrap document fixes the issue, and the cost is trivial compared to the 110 dollar per day per request penalty for failing to provide an SPD when a participant asks for one.

Mistake 7. Misclassifying 1099 contractors who are really W 2

California's AB 5 and the ABC test have tightened worker classification dramatically. If a worker you treat as a 1099 contractor would be considered an employee under the ABC test, they may have to be counted toward your ALE calculation, offered benefits, and reported on your 1095 filings. The Employment Development Department does not have to find the misclassification on purpose. A single unemployment claim from one of those workers can open the whole file.

How real employers avoid all of this

The fix is not heroic. It is structural. Every group we manage has a written annual compliance calendar that lists the deadlines, the responsible party, and the form numbers. Open enrollment notices in October. 1094 and 1095 filings in February and March. Section 125 nondiscrimination testing before year end. Cal Savers or 401k coordination. COBRA notice workflow built into the offboarding checklist. None of it is dramatic. All of it is the difference between a routine year and a six figure surprise.

What to do next

If you have not had your compliance posture reviewed in the last twelve months, you are guessing. We offer a free compliance audit for California employers in the 10 to 50 employee range that takes about thirty minutes and looks at every item above. You walk away knowing exactly where you stand, with a written summary you can share with your accountant or your attorney.