Open Enrollment 2024: Key Dates and What You Need to Know About Health Insurance

Open enrollment is the main time each year when you can sign up for, change, or renew health insurance coverage. Missing it can mean being locked into your current plan—or going without coverage—until the next year, unless you qualify for a special exception.

This guide explains when open enrollment for health insurance is in 2024, how the timing works for different types of coverage, and what you can do if you miss the deadline.

What Is Open Enrollment for Health Insurance?

Open enrollment is a limited window each year when most people can:

• Enroll in a new health insurance plan
• Switch from one plan to another
• Add or remove dependents (in some settings)
• Update certain coverage options

Outside of open enrollment, you usually can’t make changes unless you have a qualifying life event, such as losing other coverage, getting married, having a baby, or moving.

There are several different open enrollment periods to know about:

• Marketplace (ACA) health insurance
• Employer-sponsored health insurance
• Medicare
• Medicaid and CHIP (which work differently)

Each has its own schedule and rules.

When Is Open Enrollment for Marketplace Health Insurance for 2024?

Marketplace plans (often called ACA plans, “Obamacare,” or individual/family health insurance) follow a regular national pattern, with some state variations.

National Marketplace Open Enrollment for 2024 Coverage

For 2024 health plans, the core federal Marketplace open enrollment period was:

• Start: November 1, 2023
• Deadline for January 1, 2024 coverage: Typically December 15, 2023
• Final deadline for 2024 coverage: Typically January 15, 2024

If you enrolled by mid-December, coverage usually began January 1, 2024.
If you enrolled between mid-December and mid-January, coverage usually began February 1, 2024.

Some states that run their own Marketplaces may adjust these dates slightly (for example, extending deadlines by a week or two), but most follow roughly this same timeframe.

What If You’re Looking Ahead to 2025?

If you’re planning ahead and wondering when to enroll for 2025 coverage, Marketplace open enrollment typically:

• Opens around November 1 each year
• Runs through mid-January of the following year

Exact dates can vary slightly, but the pattern of early November to mid-January has been consistent.

When Is Open Enrollment for Employer Health Insurance in 2024?

If you get health insurance through your job (or a family member’s job), your employer sets its own open enrollment period.

Typical Employer Open Enrollment Timing

Most employers hold open enrollment once a year, often:

• In the fall (commonly October or November)
• For coverage that starts on or around January 1

However, some employers:

• Use a different plan year (for example, July–June)
• Have open enrollment at another time of year (for example, spring)

Your employer or benefits administrator is the best source for exact dates. Employers usually send:

• Email announcements
• Printed mailers or benefit booklets
• Notices on internal HR or benefits websites

What You Can Do During Employer Open Enrollment

During your job’s open enrollment, you may be able to:

• Enroll in your employer’s health insurance for the first time
• Switch between plan options (for example, from an HMO to a PPO)
• Add or remove dependents (spouse, partner, children)
• Adjust other benefits connected to health care, like dental, vision, or flexible spending accounts (FSAs)

If you miss your employer’s open enrollment, you typically must wait until the next year, unless you experience a qualifying life event.

When Is Open Enrollment for Medicare in 2024?

If you’re eligible for Medicare, there are several enrollment windows to keep in mind. These are separate from Marketplace or employer coverage timelines.

1. Medicare Annual Enrollment Period (AEP)

This is the main Medicare open enrollment period each year:

• Dates: October 15 – December 7 (same dates every year)
• For 2024 coverage: October 15 – December 7, 2023

Changes you make during this time generally take effect on January 1, 2024.

During AEP, you can:

• Switch between Original Medicare and Medicare Advantage
• Change from one Medicare Advantage plan to another
• Join, switch, or drop a Part D (prescription drug) plan

2. Medicare Advantage Open Enrollment Period

There is also a separate window if you are already enrolled in a Medicare Advantage plan:

• Dates: January 1 – March 31 (every year)
• During this time, you can:
  • Switch to a different Medicare Advantage plan
  • Return to Original Medicare and join a Part D plan (if desired)

3. Initial Enrollment When You First Qualify

When you first become eligible for Medicare (usually around age 65), you have an Initial Enrollment Period:

• A 7-month window that includes:
  • The 3 months before you turn 65
  • The month you turn 65
  • The 3 months after you turn 65

This is separate from the annual open enrollment and is especially important if you’re new to Medicare.

Medicaid and CHIP: Do They Have Open Enrollment?

Medicaid and the Children’s Health Insurance Program (CHIP) generally do not have a limited open enrollment period in the same way.

• You can usually apply any time of year.
• If you qualify, coverage can often start quickly, sometimes with options for retroactive coverage depending on your state’s rules.

These programs are aimed at people with certain income levels or specific eligibility criteria. If your income changes or your circumstances shift, you can often reapply or update your information without waiting for a yearly enrollment window.

Summary of 2024 Health Insurance Enrollment Windows

Below is a simple overview of the most common health insurance open enrollment periods related to 2024 coverage:

What If You Missed Open Enrollment for 2024?

If you missed the open enrollment deadline for Marketplace or employer coverage, you may still have options.

1. Special Enrollment Periods (SEPs)

You may qualify for a Special Enrollment Period if you experience a qualifying life event, such as:

• Losing other health coverage (for example, job loss, aging off a parent’s plan)
• Getting married or divorced
• Having or adopting a child
• Moving to a new area where different plans are available
• Certain changes in immigration status or household size

These events usually give you a limited window (commonly 60 days from the event) to enroll in or change coverage outside of the main open enrollment period.

2. Medicaid or CHIP

If your income or family situation has changed, it may be worth checking whether you or your children are eligible for:

• Medicaid
• CHIP (Children’s Health Insurance Program)

Because these programs often accept applications all year, they can provide coverage even when other enrollment windows are closed.

3. Short Gaps and Other Options

Some people experience short gaps in coverage due to timing. In these situations, it may help to:

• Confirm the exact start date of any new coverage you secure
• Coordinate end dates and start dates carefully to limit or avoid gaps
• Review whether you are eligible for COBRA continuation coverage if you recently lost job-based insurance (COBRA rules and costs can vary, and it is typically more expensive than active employee coverage)

How to Prepare Before Open Enrollment Starts

Going into open enrollment with a plan can save time and lead to better decisions. A few practical steps:

1. Review Your Current Coverage

Take a moment to check:

• Which doctors, clinics, and hospitals you rely on
• Whether your current plan still covers them in-network
• How often you use health services (occasional visits vs. frequent care)
• Any regular prescriptions you need covered

This helps you decide whether to stay with your current plan or look for other options during open enrollment.

2. Compare Key Plan Features

When open enrollment is available, look closely at:

• Monthly premium (what you pay every month)
• Deductible (what you pay before insurance begins to share costs)
• Co-pays and coinsurance (your share when you get care)
• Out-of-pocket maximum (the most you’d pay in a year for covered services)
• Network (which doctors and hospitals are in-network)

Balancing these items helps you choose a plan that fits your budget and expected health needs.

3. Update Your Household and Income Information (for Marketplace Plans)

If you use a Marketplace:

• Make sure your household size and income information is accurate
• This affects any premium tax credits or cost reductions you may qualify for
• Updating details yearly can help avoid surprises at tax time and ensure you’re getting the right level of financial help, if you’re eligible

Practical Tips for Making the Most of Open Enrollment

Here are some simple ways to stay on top of open enrollment for health insurance in 2024 and beyond:

• 🗓️ Mark your calendar early. Note typical dates:
  • Marketplace: Early November to mid-January
  • Medicare: October 15 to December 7
  • Employer plans: Often fall, but confirm with HR
• 📩 Watch for notices. Keep an eye on:
  • Emails from your employer
  • Mail from insurance companies or government agencies
  • Messages in online accounts (Marketplace, Medicare, employer portal)
• 📝 Make a list of your must-haves. For example:
  • Certain doctors or clinics you want in-network
  • Specific medications that need coverage
• 📚 Read summaries carefully. Focus on:
  • Summary of Benefits and Coverage (SBC)
  • Plan brochures or comparison charts provided during enrollment

Taking these steps during the open enrollment period can help you choose a plan that better fits your needs and reduces surprises during the year.

Key Takeaways: Open Enrollment for Health Insurance 2024

• Marketplace (ACA) plans for 2024: Open enrollment ran from November 1, 2023, through about mid-January 2024, with coverage starting in January or February depending on when you enrolled.
• Employer plans: Open enrollment is set by your employer, often in the fall for coverage effective January 1, but timing can vary.
• Medicare: The main open enrollment (Annual Enrollment Period) is October 15 – December 7 each year, affecting coverage for the following year.
• Medicaid and CHIP: Generally year-round enrollment, based on eligibility.
• If you missed open enrollment, you may still qualify for a Special Enrollment Period, Medicaid, or other options depending on your circumstances.

Understanding these timelines helps you avoid coverage gaps and make more informed choices about your health insurance from year to year.