Open enrollment is the one stretch of the year when you can change most workplace benefits without a special reason. Employers with calendar-year plans usually hold it in the fall, and the window is often short. Once it closes, your elections are generally locked for the plan year unless you have a qualifying life event, such as marriage, a birth or adoption, or losing other coverage.
This guide covers how to compare plans with real numbers, HSAs versus FSAs, the other elections worth checking, and which 2027 figures are official as of October 18, 2026.
The 2027 numbers: official and pending
| Item | 2027 figure | Status |
|---|---|---|
| HSA contribution limit | $4,500 self-only / $9,000 family | Official |
| HSA catch-up, age 55+ | $1,000 | Official, fixed by law |
| HDHP minimum deductible | $1,750 self-only / $3,500 family | Official |
| HDHP out-of-pocket maximum | $8,700 self-only / $17,400 family | Official |
| Health FSA limit | Not announced ($3,400 in 2026) | Pending |
| Dependent care FSA | $7,500 per household | Set by law, not indexed |
The HSA and HDHP figures come from IRS Revenue Procedure 2026-24. The health FSA limit comes in the IRS's annual inflation-adjustment release, which had not been published as of October 18, 2026. If your plan allows carryover, up to $680 of unused 2026 health FSA money can roll into 2027. Employers can set lower caps, so your enrollment portal has the final word.
How to compare health plans with real math
Compare every plan on three numbers, not the premium alone:
- Expected cost: annual premiums plus likely out-of-pocket spending, based on last year's claims and any planned care.
- Worst case: annual premiums plus the out-of-pocket maximum.
- Employer HSA money: subtract it, since it offsets costs you'd otherwise pay.
The plan numbers below are hypothetical, for illustration only. Plan B's deductible and out-of-pocket maximum fall within the 2027 IRS rules for a self-only HDHP. Both plans charge 20% coinsurance after the deductible.
| Plan A: PPO | Plan B: HDHP with HSA | |
|---|---|---|
| Your premium | $160/month ($1,920/year) | $100/month ($1,200/year) |
| Deductible | $1,000 | $3,000 |
| Out-of-pocket maximum | $5,000 | $7,000 |
| Employer HSA contribution | None | $500 |
| Scenario | Plan A total | Plan B total |
|---|---|---|
| Light year: $500 of care | $1,920 + $500 = $2,420 | $1,200 + $500 − $500 = $1,200 |
| Typical year: $4,000 of care | $1,920 + $1,600 = $3,520 | $1,200 + $3,200 − $500 = $3,900 |
| Worst case | $1,920 + $5,000 = $6,920 | $1,200 + $7,000 − $500 = $7,700 |
Plan B wins the light year by $1,220 and loses the typical and worst-case years by $380 and $780. Neither is better in general; it depends on how much care you expect and whether savings could cover the higher worst case. Your own HSA contributions also cut taxable income, narrowing Plan B's gap by an amount that depends on your tax bracket.
The Monthly Budget Calculator shows how the premium and any FSA set-aside fit your monthly cash flow.
HSA vs. health FSA vs. limited-purpose FSA
| HSA | Health FSA | Limited-purpose FSA | |
|---|---|---|---|
| Needs an HSA-eligible plan | Yes | No | Usually paired with one |
| Unused money | Stays yours; can be invested | Forfeited unless the plan offers a carryover or grace period | Same as a health FSA |
A health FSA is use-it-or-lose-it. A plan can soften that with a carryover or a grace period of up to 2½ months after the plan year ends, not both. Elect only spending you can predict.
An HSA keeps every dollar, and employer contributions count toward your limit. A general-purpose health FSA, yours or your spouse's, blocks HSA contributions; a limited-purpose FSA covers mainly dental and vision so you can use both. The HSA guide covers investing the balance, and the Compound Interest Calculator shows what invested HSA dollars could grow to.
A dependent care FSA pays for care of a child under 13, or a spouse or dependent who can't care for themselves, so you can work. The limit rose to $7,500 per household ($3,750 married filing separately) starting in 2026 under the 2025 tax law. Expenses paid through it can't also count toward the child and dependent care credit.
Retirement elections
Most 401(k) plans let you change your contribution rate any time, but open enrollment is a natural moment to revisit it. If your employer matches, contributing enough to get the full match is a common first step.
The 2026 employee limit is $24,500. The IRS had not announced 2027 limits as of October 18, 2026, and typically does so in late October or November; the 2027 contribution limits guide tracks which figures are official. The Coast FIRE Calculator shows whether what you've already invested could grow to your retirement number on its own.
Other elections worth a second look
- Life insurance. Group coverage usually ends with the job, and employer-paid coverage above $50,000 adds taxable imputed income.
- Disability insurance. If your employer pays the premiums or you pay pre-tax, benefits are generally taxable; with after-tax premiums, they generally aren't.
- Voluntary benefits. Accident, critical illness and hospital indemnity plans supplement health coverage; they don't replace it.
- Dependents and beneficiaries. Children can generally stay on a parent's plan until 26. Confirm beneficiaries on life insurance and your 401(k).
Marketplace and Medicare dates for 2027
ACA Marketplace. As of October 18, 2026, HealthCare.gov lists open enrollment for 2027 coverage as November 1, 2026 through January 15, 2027; enroll by December 15 for coverage starting January 1. A 2025 federal rule would have ended the window on December 15, but a federal court vacated that provision in June 2026 and the government has appealed. State-run exchanges set their own dates.
The enhanced premium tax credits expired after 2025, and as of October 18, 2026, Congress has not extended them. 2027 credits follow the original rules, which generally limit eligibility to household incomes between 100% and 400% of the federal poverty level. Bronze and catastrophic Marketplace plans have counted as HSA-compatible since January 1, 2026.
Medicare. For anyone 65 or older, or helping a parent, Medicare Open Enrollment runs October 15 to December 7, 2026, with changes effective January 1, 2027. You don't need to re-enroll to keep current coverage. Once enrolled in Medicare, you can't contribute to an HSA.
Common open enrollment mistakes
- Auto-renewing without looking. Premiums, networks and drug lists change even when the plan name doesn't.
- Skipping the network check for your doctors and prescriptions.
- Pairing an HSA with a general-purpose FSA, including a spouse's.
- Assuming FSA elections roll over. Many plans require a new election each year.
Your open enrollment checklist
- Find your enrollment deadline.
- Pull last year's medical, dental and prescription costs.
- Confirm doctors and prescriptions for each 2027 plan.
- Calculate expected and worst-case totals; subtract employer HSA money.
- Set HSA or FSA contributions against 2027 limits.
- Revisit your 401(k) rate.
- Review life, disability and voluntary coverage.
- Update dependents and beneficiaries.
- Check your first 2027 paycheck.
Frequently asked questions
What if I miss my open enrollment deadline?
You're generally kept on your current elections until next year unless you have a qualifying life event. Marriage, a birth or adoption, or losing other coverage triggers a special enrollment right in employer plans, and the plan must allow at least 30 days to request it.
Can I have an HSA and an FSA at the same time?
Not with a general-purpose health FSA, which blocks HSA contributions. A limited-purpose FSA for dental and vision is compatible, and a dependent care FSA doesn't affect HSA eligibility.
Is a high-deductible plan always cheaper?
No. Lower premiums and employer HSA money can win a light year, but the higher deductible and out-of-pocket maximum can cost more in a heavy one. Compare expected and worst-case totals, and make sure savings could cover the deductible.
When will the 2027 health FSA and 401(k) limits be announced?
As of October 18, 2026, the IRS hadn't published either; both are typically released in October or November. If your enrollment closes first, ask HR how your plan will apply the new limits.
Disclaimer
This guide is for general educational purposes only and does not constitute personalized financial, tax, or legal advice. Every reader's situation is different — consult a licensed financial advisor, accountant, or attorney before making decisions based on this content. Figures and rules cited here reflect the most recent information available at time of publication and may change; verify current limits and regulations before acting.