The short version
- Full-time under the ACA means an average of 30 hours a week, or 130 a month.
- Under the look-back method, an unpaid summer can't be counted as zero-hour weeks. Leave it out of the average or credit it at the normal weekly rate, up to 501 hours a year.
- A school-year employee coming back in August is a continuing employee. For schools, the break that resets someone is 26 weeks, not 13.
- There is no special IRS rule for subs or coaches. Every paid hour with the district counts.
Districts fall under the employer mandate like any employer with 50 or more full-time and full-time-equivalent employees.1 The difference is the nine-month calendar, and the regulations have rules written for it.
What counts as an hour
Every paid hour of work, plus paid hours off for vacation, holidays, illness, disability, jury duty, military duty or leave.2 Paid winter and spring breaks and sick days count.3 The 501-hour cap below applies only to unpaid breaks.4 For staff not paid hourly, a district can use actual hours, 8 per day worked or 40 per week worked, as long as the method doesn't substantially understate real hours.5
The summer break rule
An unpaid stretch of four or more weeks for a school employee is an "employment break period."2 Under the look-back method the district either leaves those weeks out of the average or credits them at the employee's usual weekly rate. Both give the same answer.5
| Method | Arithmetic | Weekly average |
|---|---|---|
| Counting summer as zero (not allowed) | 1,280 hours ÷ 52 weeks | 24.6 |
| Leaving the break out | 1,280 hours ÷ 40 weeks | 32.0 |
| Crediting the break | (1,280 + 12 × 32) ÷ 52 weeks | 32.0 |
That para is full-time. A 25-hour para averages 25 either way and is not. The test is whether the person would be full-time if school ran all year.
The credit is capped at 501 hours per calendar year.5 Twelve weeks at 32 hours is 384, so the cap doesn't bite here. It matters for longer breaks or higher weekly hours.
This applies only to the look-back method. Under the monthly method each month stands alone, so a para with no hours in July isn't full-time for July.5
Returning staff: 26 weeks, not 13
Most employers can treat someone back after 13 weeks with no hours as a new hire. For a school it takes 26.5 A summer doesn't come close, so an aide who leaves in May and returns in August keeps their status.
The optional "rule of parity" is the exception: after a break of at least four weeks that is longer than the time the person worked before it, the district may treat them as new.5 A sub who worked six weeks in spring and then nothing for 12 qualifies. An aide with a full school year behind them doesn't.
New hires: summer can't be assumed away
A district can't factor in the summer break when deciding whether a new hire is expected to be full-time.2 A new para at 32 hours a week is a full-time hire, not variable-hour. "Seasonal" doesn't fit either, since school-year jobs run longer than six months.2 The IRS said early on that calling school-year staff seasonal isn't a reasonable reading.3
Substitutes
No rule is written specifically for subs. A sub hired directly is usually variable-hour: track hours over a 3 to 12 month measurement period and offer coverage if they average 30 or more.5 Watch subs who work most days across buildings, and anyone moving into a long-term assignment. If the district expects that assignment to be full-time, coverage is generally due by the first day of the fourth full month after the change.5
Using a staffing agency doesn't settle it. The IRS has said schools have used agencies to sidestep these rules, and the agency may not be the real employer.4 If the district controls the sub's work, it should know how those hours are counted and who offers coverage.
Coaches, bus routes and second jobs
All paid hours with the district add together.2 On our reading, a para who also drives a route and coaches volleyball has a single hours total, not three.
Stipend work needs a reasonable way to credit hours, and a method that makes a full-time job look part-time isn't reasonable.6 The often-quoted 2¼ hours per classroom hour was written for college adjuncts, not K-12.6 Having coaches log real hours for one season gives you a defensible basis.
What a miscount costs
The district has to offer coverage to at least 95% of full-time employees and their children up to age 26.7 Miss that, and if even one full-timer gets subsidized exchange coverage, the 2026 penalty is $3,340 per full-time employee after the first 30.1,8 For a district with 200 full-timers where 12 misclassified paras drop it below 95%, that's 170 × $3,340 = $567,800 for the year.
A check to run this month
- Pull paid hours by person, not position, for the whole measurement period. Add every job they hold.
- For anyone with an unpaid stretch of four weeks or more, recompute the average with those weeks left out.
- List everyone at 28 hours or more. That's where mistakes cluster.
- Confirm everyone at 30 or more has an offer of coverage on file for the current stability period.
- Ask any sub agency, in writing, how it counts hours and whether it offers coverage.