The 2027 open enrollment season is shaping up to be the most consequential in years. PwC projects a 9% medical cost trend for 2027, the highest in 17 years. The ACA open enrollment window is shorter. And the One Big Beautiful Bill Act (OBBBA) introduces Medicaid work requirements starting January 2027 that will push millions of people toward marketplace or employer-sponsored coverage.
Whether you are an employer planning benefits for your team, an individual shopping on Healthcare.gov, or a broker advising clients, this guide covers every 2027 open enrollment deadline, ACA open enrollment date, and tax savings strategy you need.
When Does Open Enrollment Start for 2027?
Open enrollment for 2027 health insurance starts on November 1, 2026, on Healthcare.gov and in most states. This is the ACA open enrollment period (ACA OEP 2027) when individuals and families can enroll in, change, or drop marketplace health insurance plans for the 2027 coverage year.
Two states begin earlier:
- Idaho: October 15, 2026
- Georgia: October 19, 2026
All other states using Healthcare.gov or their own state-based marketplace begin ACA open enrollment for 2027 on November 1, 2026.
For employer-sponsored health plans, open enrollment dates are set by each employer, not by the federal government. Most employers with a January 1 plan year hold open enrollment in October or November 2026. Employer plan enrollment is separate from the ACA marketplace open enrollment 2027 window.
What Is the Open Enrollment 2027 Deadline?
The open enrollment 2027 deadline for Healthcare.gov marketplace plans is December 15, 2026. All plans selected by December 15 take effect January 1, 2027.
This is a shorter ACA OEP 2027 window than in previous years. In past enrollment periods, some states allowed enrollment through January 15 or later. For 2027, the ACA open enrollment deadline is firm at December 15 in most states. State-based marketplaces may extend their deadline but cannot go past December 31, 2026, and the total open enrollment window cannot exceed 9 weeks.
There is no longer an option for a February 1 start date during open enrollment. All 2027 marketplace plan selections take effect January 1, 2027.
2027 open enrollment deadlines by marketplace type:
| Marketplace | Open Enrollment Start | Open Enrollment 2027 Deadline | Coverage Start |
|---|---|---|---|
| Healthcare.gov (most states) | November 1, 2026 | December 15, 2026 | January 1, 2027 |
| Idaho | October 15, 2026 | December 15, 2026 | January 1, 2027 |
| Georgia | October 19, 2026 | December 15, 2026 | January 1, 2027 |
| State-based marketplaces | November 1, 2026 | Up to December 31, 2026 | January 1, 2027 |
For employer-sponsored plans, the open enrollment deadline is set by each employer. Most employers close enrollment two to four weeks after it opens. Employees should check with their HR department for exact dates.
What Is ACA Open Enrollment?
ACA open enrollment is the annual period when Americans can sign up for health insurance through the Affordable Care Act marketplace, also called the Health Insurance Marketplace or Healthcare.gov. ACA stands for the Affordable Care Act, the federal law signed in 2010 that created the marketplace system.
During ACA open enrollment, individuals and families can:
- Enroll in a new marketplace health insurance plan
- Switch to a different plan
- Drop marketplace coverage
- Update income and household information that affects premium tax credits
Outside of ACA open enrollment, individuals can only enroll in or change marketplace coverage if they experience a qualifying life event, such as marriage, birth of a child, loss of other coverage, or a change in Medicaid or CHIP eligibility.
The ACA open enrollment period is different from employer-sponsored open enrollment. If you get health insurance through your job, your employer sets the enrollment dates independently. But the ACA OEP 2027 dates matter to employers too, because employees who do not enroll in employer coverage may turn to the marketplace as an alternative.
What Are the 2027 ACA Open Enrollment Dates?
The 2027 ACA open enrollment dates are November 1, 2026, through December 15, 2026, for Healthcare.gov states. State-run marketplaces may set slightly different dates but must start by November 1 and end no later than December 31, 2026.
Here is a month-by-month breakdown of every important date:
| Date | What Happens |
|---|---|
| October 15, 2026 | Idaho marketplace open enrollment begins |
| October 19, 2026 | Georgia marketplace open enrollment begins |
| November 1, 2026 | ACA open enrollment 2027 begins on Healthcare.gov and most state marketplaces |
| December 15, 2026 | Open enrollment 2027 deadline on Healthcare.gov. Last day to enroll for January 1 coverage |
| December 31, 2026 | Latest possible deadline for state-based marketplaces |
| January 1, 2027 | 2027 coverage begins for all plans selected during open enrollment |
| January 2027 | OBBBA Medicaid work requirements take effect. Qualifying life events may trigger special enrollment |
These ACA open enrollment dates apply to individual and family marketplace plans. Employer-sponsored plan enrollment runs on a separate schedule set by each employer.
How Do Employers Prepare for Open Enrollment 2027?
Employer-sponsored open enrollment runs on a timeline set by the employer, not by Healthcare.gov or the ACA marketplace. But the 2027 ACA open enrollment dates still matter to employers, because employees who miss the employer enrollment window may try to enroll through the marketplace instead.
Employers should begin planning at least 90 days before their enrollment window opens. For a November 2026 enrollment period, that means starting no later than August 2026.
2027 open enrollment planning timeline for employers:
| Timeframe | Action |
|---|---|
| August 2026 (90 days out) | Review current plan performance and claims data. Request renewal rates from carriers. Compare alternative plan designs (HDHP + HSA, level-funded, ICHRA). |
| September 2026 (60 days out) | Finalize 2027 plan offerings and employer contribution strategy. Confirm Section 125 plan document is current or set up a new plan. Update HSA limits to the 2027 IRS figures ($4,500 individual / $9,000 family). |
| Early October 2026 (45 days out) | Prepare employee communication materials in plain language. Schedule enrollment meetings, webinars, or one-on-one sessions. |
| Mid-October 2026 (30 days out) | Send first enrollment announcement to all eligible employees, including those on leave, remote workers, and COBRA participants. Distribute required compliance notices. |
| Late October 2026 (14 days out) | Send reminder with enrollment window dates, plan comparison guides, per-paycheck cost breakdowns, and decision-support resources. |
| November 2026 (enrollment window) | Hold information sessions. Provide live support for questions. Keep enrollment systems accessible on mobile and desktop. |
| Early December 2026 (post-close) | Verify elections. Reconcile data with carriers. Submit payroll deduction updates for January 2027. |
Why Is the 2027 Open Enrollment Season More Expensive Than Previous Years?
Three forces are driving costs higher for the 2027 plan year.
Medical Cost Trend Hits a 17-Year High
PwC's Health Research Institute surveyed actuaries at 27 U.S. health plans covering more than 103 million employer-sponsored members and 8 million individual ACA marketplace members. PwC projects the group medical cost trend for 2027 at 9%, the highest since 2010.
The drivers behind the 9% trend include:
- Prescription drug spending, particularly GLP-1 medications like Ozempic and Mounjaro, now covered by 49% of large employers according to Mercer
- Provider adoption of AI-enabled revenue optimization tools, which increase billing accuracy and reimbursement capture
- Behavioral health utilization, which continues to grow as demand for mental health services outpaces provider supply
- Out-of-network payment disputes under the No Surprises Act, which are increasing administrative costs
Mercer's National Survey found that employer health benefit costs already exceeded $18,500 per employee in 2026 after a 6.7% increase. At a 9% trend, the average employer cost per employee could surpass $20,000 in 2027 for the first time.
The Peterson-KFF Health System Tracker reported a median 11% premium increase for small group plans in 2026. Early 2027 rate filings suggest another high single-digit increase unless pharmacy costs ease. For a state-by-state breakdown, see Health Insurance Premium Increase by State.
The OBBBA Changes Medicaid Eligibility Starting January 2027
The One Big Beautiful Bill Act, signed July 4, 2025, introduces Medicaid work requirements in the 40 states (plus Washington, D.C.) that expanded Medicaid. Starting January 2027, enrollees must prove they are working, volunteering, or attending school at least 80 hours per month, or qualify for an exemption. States must verify eligibility twice per year instead of once.
The Congressional Budget Office (CBO) estimates roughly 15 million people will lose health coverage by 2034 due to the combined Medicaid and ACA marketplace changes. For employers, this means more workers and applicants may seek employer-sponsored coverage as their primary option.
For a full analysis, see One Big Beautiful Bill and Health Insurance.
ACA Enhanced Subsidies Are Expiring
The enhanced premium tax credits that made marketplace coverage on Healthcare.gov more affordable since 2021 were not extended by the OBBBA. As subsidies shrink, individual marketplace premiums rise, making employer-sponsored group coverage comparatively more valuable. Employers that communicate this advantage during open enrollment 2027 will see higher participation rates.
How Does a Section 125 Plan Help Employers During Open Enrollment 2027?
A Section 125 cafeteria plan is the IRS-approved structure that allows employees to pay for health insurance premiums, FSA contributions, and other qualified benefits with pre-tax dollars. Without a Section 125 plan in place before the 2027 plan year starts, employee premium contributions are deducted after tax, and the employer loses FICA savings entirely.
Employees make their Section 125 elections during open enrollment. Under IRS rules, these elections are irrevocable for 12 months unless the employee experiences a qualifying life event.
How FICA recapture works for employers in 2027:
The employer saves 7.65% (the employer share of Social Security and Medicare taxes) on every dollar employees contribute pre-tax. The IRS publishes the FICA rate structure annually.
For a business with 30 employees contributing an average of $500/month in pre-tax premiums:
- Monthly pre-tax contributions: $15,000
- Employer FICA avoided: $1,147.50/month ($15,000 x 7.65%)
- Annual employer FICA savings: $13,770
- Annual Summit admin fee: $12,600 ($35 x 30 x 12)
- Net annual savings to employer: $1,170, plus each employee sees $70 to $110 more per month in take-home pay
Even when employer FICA savings are close to the admin fee, the employee income tax savings (federal, state, and local) make the benefits package more competitive at zero additional employer cost. The $35 PEPM admin fee is funded from reduced FICA deposits on IRS Form 941, not from operating cash.
For a detailed breakdown, see Maximizing FICA Tax Savings with Section 125.
What Are the 2027 HSA and FSA Limits?
The IRS announced 2027 Health Savings Account (HSA) limits on May 29, 2026. Employers offering high-deductible health plans (HDHPs) paired with HSAs should update their open enrollment materials to reflect these figures.
| Category | 2026 Limit | 2027 Limit | Change |
|---|---|---|---|
| HSA contribution (individual) | $4,400 | $4,500 | +$100 |
| HSA contribution (family) | $8,750 | $9,000 | +$250 |
| HSA catch-up (age 55+) | $1,000 | $1,000 | No change |
FSA limits for 2027 have not yet been announced. The IRS typically releases FSA, dependent care, and transit benefit limits in the fall. Employers should prepare enrollment materials with placeholder language and update when final numbers are published.
What Compliance Notices Must Employers Send for 2027 Open Enrollment?
Employers must distribute several federally required notices before or during open enrollment. Missing any of these creates legal exposure.
Summary of Benefits and Coverage (SBC). Required under the ACA for every health plan option. Must be provided during open enrollment and upon request. Uses a standardized format.
COBRA general notice. Must be provided to new enrollees within 90 days of coverage start. For details, see COBRA Health Insurance.
HIPAA special enrollment rights notice. Informs employees about their right to enroll mid-year after qualifying events.
Medicare Part D creditable coverage notice. Required annually before October 15.
Women's Health and Cancer Rights Act notice. Must be delivered at enrollment.
CHIP/Medicaid notice. Required annually. More important than ever given the OBBBA Medicaid changes starting January 2027.
Mental Health Parity disclosure. Under the Mental Health Parity and Addiction Equity Act (MHPAEA), employers offering mental health benefits must provide comparative analyses showing that coverage limitations for mental health are no more restrictive than for medical/surgical benefits. The Department of Labor (DOL) has increased enforcement in this area.
Employers with 50 or more full-time equivalent employees also face ACA reporting (Forms 1094-C and 1095-C) and must offer minimum essential coverage under the IRS employer mandate.
What Are the Biggest Open Enrollment 2027 Mistakes Employers Make?
Starting Too Late
With a 9% cost trend in 2027, rate negotiations need to start 90 days before enrollment, not 30. Employers that rush their timeline end up with worse rates and confused employees.
Not Having a Section 125 Plan Ready
The IRS does not allow retroactive Section 125 plans. If the plan document is not signed before the 2027 plan year begins, pre-tax elections are invalid for the entire year. Summit Health Benefits can have a Section 125 plan set up in days, but starting early avoids last-minute pressure.
Using Jargon Instead of Plain Language
A MetLife benefits study found that 44% of workers did not consult anyone before making enrollment decisions. Replace terms like "coinsurance" and "actuarial value" with plain-English explanations and real dollar examples.
Forgetting Employees on Leave or COBRA
Employers must send open enrollment materials to all eligible individuals, including employees on FMLA leave, disability leave, or COBRA continuation. Skipping them violates ERISA.
Ignoring the OBBBA Medicaid Impact
Employers that do not plan for employees losing Medicaid in 2027 may face a surge of mid-year special enrollment requests. Losing Medicaid qualifies as a special enrollment event, giving employees 30 days to enroll in employer coverage.
Skipping Post-Enrollment Verification
Enrollment errors (duplicate entries, missing dependents, wrong plan codes) cause claim denials. A post-enrollment audit that reconciles elections against carrier records catches problems before they become crises.
How Can Employers Offer Better 2027 Benefits Without Spending More?
Set up a Section 125 plan. Pre-tax premium deductions save the employer 7.65% in FICA. Summit Health Benefits administers Section 125 plans for $35 PEPM, with a net employer benefit of $56 to $101 PEPM after the admin fee.
Add voluntary benefits at no employer cost. Accident insurance, critical illness, and hospital indemnity can be offered through payroll deduction at zero employer cost. Pre-tax deductions through Section 125 reduce the employee's cost too. See Zero-Cost Employee Health Benefits.
Pair an HDHP with an HSA. The 2027 HSA family limit of $9,000 gives employees a powerful triple-tax-advantaged savings tool. Even a small employer HSA seed contribution ($500 to $1,000/year) offsets the higher deductible.
Consider ICHRA. An Individual Coverage HRA lets employers reimburse employees for individual marketplace premiums bought during ACA open enrollment 2027, giving employees more choice with a fixed employer cost. See How Does ICHRA Work?.
Negotiate early. Start renewal conversations 90 days before open enrollment. A 2-3% reduction on a $400,000 annual premium spend saves $8,000 to $12,000.
What Happens After the 2027 Open Enrollment Deadline Passes?
After the open enrollment 2027 deadline, both marketplace enrollees and employees in employer plans are locked into their selections for the plan year. Here is what employers need to do after enrollment closes.
Audit elections. Compare submitted elections against carrier enrollment files. Look for missing dependents, incorrect plan codes, and duplicate entries.
Update payroll for January 2027. Confirm that pre-tax deduction amounts match elected plans. Incorrect deductions create W-2 reporting problems at year-end.
Send confirmation statements. Give every enrolled employee a written summary of their elections, effective dates, and per-paycheck deductions.
Submit carrier changes. File adds, drops, and plan changes with each carrier within the required window (usually 30 days).
Store Section 125 election forms. Retain signed election forms for at least three years for IRS audit documentation.
Prepare for mid-year Medicaid transitions. With OBBBA work requirements taking effect January 2027, expect employees to lose Medicaid and seek employer coverage through special enrollment. Have a streamlined process ready.
Update COBRA administration. New enrollees trigger COBRA general notice obligations. See COBRA continuation rules for requirements.
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Frequently Asked Questions
When does open enrollment start for 2027?
What is the open enrollment 2027 deadline?
What is ACA open enrollment?
What are the ACA open enrollment dates for 2027?
How do I enroll in marketplace open enrollment 2027 on Healthcare.gov?
How much are health insurance costs increasing for 2027?
What is a Section 125 plan and how does it save money during open enrollment?
Can I enroll in health insurance outside of open enrollment in 2027?
Sources
- PwC Health Research Institute, "Medical Cost Trend 2027: Behind the Numbers"
- Mercer National Survey of Employer-Sponsored Health Plans, 2025
- Mercer, "Employers Prepare for the Highest Health Benefit Cost Increase in 15 Years"
- KFF 2025 Employer Health Benefits Survey, Kaiser Family Foundation
- Peterson-KFF Health System Tracker, "How Much and Why Premiums Are Going Up for Small Businesses in 2026"
- Congressional Budget Office (CBO), coverage impact estimates for the One Big Beautiful Bill Act
- IRS, 2027 HSA and HDHP Contribution Limits (announced May 29, 2026)
- IRS, Section 125 Cafeteria Plan Regulations
- Department of Labor (DOL), COBRA and ERISA Notice Requirements
- Centers for Medicare and Medicaid Services (CMS), Marketplace Enrollment Data
- healthinsurance.org, ACA Open Enrollment Dates and Deadlines for 2027
- MetLife Annual Benefits Study
- Healthcare.gov, Open Enrollment Dates and Qualifying Life Events