What Is Open Enrollment?

Open enrollment is an annual window to enroll in, change, or cancel an insurance plan for you and your family for the upcoming year. There are open enrollment periods for insurance plans from the ACA Marketplace, your employer, and Medicare. Insurers limit enrollment to certain periods to prevent people from only signing up for insurance when they’re sick, which would drive up rates for everyone.

Key Takeaways

Health insurance plans feature open enrollment periods during which you can select, change, or adjust your coverage.
If you miss the open enrollment period, you may have to wait until the next open enrollment or qualify for a special enrollment period to make health plan changes.
Open enrollment for ACA Marketplace plans is usually from November 1 to January 15, and Medicare’s is October 15 to December 7. Employer open enrollment periods vary but typically start in the fall.
Coverage commonly starts the following year.

How Open Enrollment Works

During open enrollment, you may be able to:

Get estimates of health insurance plan features and prices
Enroll in a Marketplace, Medicare, or employee health insurance plan
Cancel your health insurance plan
Switch to another health insurance plan

You can also make adjustments to your plan, such as:

Adding or removing dependents or a spouse
Adjusting your coverage levels
Adding, switching, or removing adult vision and dental coverage if plans are offered

You can still usually purchase a plan outside of open enrollment, but only if you have a qualifying life event, such as losing job-based coverage or getting married.

Tip

The open enrollment period is sometimes abbreviated as OEP.

What Types of Insurance Use Open Enrollment?

Open enrollment periods exist for the Affordable Care Act health and dental plans, job-based healthcare plans, and Medicare plans. Let’s examine each.

ACA Health Insurance

Healthcare.gov is the Health Insurance Marketplace website for 32 states. Another 18 states have their own marketplaces. A handful of states have different open enrollment periods and rules for when coverage takes effect. But dates only differ by a few weeks, typically.

Fast Fact

American Indians and Alaska Natives can enroll in a Marketplace plan at any time, not just during open enrollment.

Employer Health Insurance

An employer’s annual open enrollment period allows you to sign up for or change your group-based insurance plans, including health, vision, and dental, if offered. You may also be able to sign up for group life insurance plan coverage.

Open enrollment is usually a few weeks before your employer needs to submit enrollment forms to providers. For employer-sponsored plans with coverage beginning January 1, open enrollment usually starts in November and runs for at least two to four weeks.

Note

If you have continued your employer’s health insurance coverage through COBRA, you will participate in your employer’s standard open enrollment period along with current employees.

Medicare

During Medicare open enrollment, you can change health and prescription drug plans or adjust your medical plans on Medicare.gov. Reviewing your current coverage is important because Medicare Advantage (MA) plan coverage can change. Another plan could better serve your needs and budget.

Medicare also has a separate Medicare Advantage open enrollment period for people already in an MA plan. During this period, you can switch to a new Medicare Advantage or drug plan or to Original Medicare.

Open Enrollment Dates

Here are important open enrollment dates and their significance.

Important Open Enrollment Dates: Marketplace Health Insurance
November 1	Open enrollment starts for next year’s health insurance coverage. Use the Marketplace to enroll, renew, or change health insurance plans.
December 15	The last day to enroll or make plan changes and have coverage start on January 1. If you don’t sign up by December 15, coverage begins February 1. Your premium is due when your coverage goes into effect.
January 15	Last day to enroll or adjust your Marketplace health insurance plan for the year. After this date, you can only drop or change your coverage if you have a qualifying life event.

Important Open Enrollment Dates: Medicare and Medicare Advantage
October 15	Open enrollment starts for next year’s Medicare health insurance coverage for people who already have Medicare. You can change your coverage under Part A or B. You can also switch, drop, or join a Medicare Advantage plan or Medicare Part D prescription drug plan. Or you can switch from Original Medicare plan to a Medicare Advantage plan and vice versa.
December 7	Last day to make changes to Original Medicare health and drug plans.
January 1	If you’re already in a Medicare Advantage plan, this is another period when you can switch to a different MA plan (with or without drug coverage), return to Original Medicare, or join a separate drug plan.
March 31	Last day to make MA plan changes. Coverage starts the first of the month after your plan provider gets your request.

What Types of Insurance Don't Use Open Enrollment?

Medicaid and the Children’s Health Insurance Program (CHIP) have a year-round open enrollment period so that you can apply anytime through the Marketplace or directly with your state Medicaid agency.

These joint federal and state insurance programs provide free or low-cost health coverage to low-income adults and children who meet eligibility requirements.

Income limits depend on various factors, including whether your state has expanded Medicaid. The best way to determine if your unique family situation qualifies you is to fill out an application.

Can I Make Changes Outside Open Enrollment?

You can only make changes outside open enrollment if you experience a life event that qualifies you, triggering a special enrollment period.

You can cancel your coverage or a plan member’s existing Marketplace health insurance at any time of the year. But you won’t be able to apply for new coverage until the next open enrollment or a special enrollment period.

For job-based plans, you must generally wait until your company’s next open enrollment to cancel your policy (unless you have a qualifying life event).

Warning

If you cancel your COBRA insurance, you must wait until the next Marketplace open enrollment period to buy a Marketplace plan.

What If I Miss the Open Enrollment Period?

If you miss open enrollment, check whether you qualify for a special enrollment period for Medicare, ACA, and employer-sponsored health insurance plans. Remember: You can apply for Medicaid or CHIP anytime if you qualify. If none of the above applies to you, you still have options to help cover future medical bills.

Short-Term Health Plans

Short-term health insurance is a temporary, limited medical policy that may be a better alternative to no coverage. With these plans, you can often start coverage immediately and aren’t required to stay within a provider network.

However, the plans are not available in all states and don’t cover ACA essential benefits. The plans typically exclude pre-existing conditions, have limited coverage, and impose lifetime maximum coverage limits that leave you paying anything over that stated limit.

Note

Short-term health insurance plans issued or sold starting September 1, 2024, will have a maximum duration of four months (including renewals).

Healthcare Sharing Ministry (HCSM) Programs

In these faith-based, nonprofit organizations, members voluntarily make regular contributions to cover each other’s qualifying medical expenses. Healthcare sharing ministries covered $1.1 billion in medical expenses in 2023.

However, HCSMs are not health insurance plans. They aren’t licensed, regulated, or insured by any board or entity. They also usually require members to be of a particular faith and may not cover specific procedures due to the HCSM’s values.

How to Prepare for Open Enrollment

Prepare for open enrollment by comparing your current and potential future medical needs to your current health insurance plan. Look for coverage gaps and ways to save money on insurance premiums and out-of-pocket costs.

While it’s impossible to predict future conditions, you may know of surgeries and medications you or your family members will need or health concerns that may lead to a new diagnosis.

Here are some more specific checklists to help guide you through the OEP.

Health Insurance Marketplace Open Enrollment Preparation

Estimate your expected income and plan participants for the upcoming year.
Verify if you qualify for cost-sharing reductions or other federal health insurance programs in the forthcoming year.
Once the site opens, compare metal-level plan options and premiums on the federal or state website. Many allow you to enter specific care providers and medications to predict out-of-pocket costs more accurately.

Job-Based Health Insurance Open Enrollment Preparation

Make sure the contact information in your employee file is up to date. Verify your mailing address, email, and phone number with your HR department.
Your company will likely provide plan information for the upcoming year one to two months before open enrollment. Review your benefit options, insurance choices, important deadlines and dates, rate sheets, brochures, and other literature provided.
Contact your HR department to ask questions. Some companies hold Q&A sessions.

Medicare Open Enrollment Preparation

In September, you’ll receive an Annual Notice of Change (ANOC) letter detailing changes to your plan’s coverage and cost for the following year. Check for changes to your Medicare Advantage plan (Part C) or Medicare prescription drug plan (Part D). Call your provider if you don’t get one.
Review and compare the Medicare options available through the Medicare site.
If you have questions or need personalized guidance, call 1-800-MEDICARE (1-800-633-4227) or your local State Health Insurance Assistance Program (SHIP).

Frequently Asked Questions (FAQs)

Is There an Open Enrollment for Dental or Vision Insurance?

In the workplace and federal or state health insurance marketplaces, open enrollment periods for dental and vision care insurance are the same as those for health plans. You may only be able to add or change your vision or dental plan during this time. However, you can also buy independent dental and vision plans online at any time of the year.

How Long Is the Open Enrollment Period?

How long open enrollment lasts depends on your location and the type of health insurance you have:

Healthcare.gov Marketplace health plans have an OEP of almost three months.
Medicare open enrollment runs for almost two months.
Medicare Advantage’s annual open enrollment lasts for three months.
Group health insurance plan open enrollment dates vary but usually last two to four weeks.

What Is a Qualifying Life Event?

Qualifying life events allow you to enroll in a health insurance plan outside of the open enrollment period. Types of qualifying events with examples include:

Loss of health coverage: Losing existing health coverage or eligibility for government-based insurance programs such as Medicaid
Changes in household: Getting married or divorced, having a baby, or adopting a child
Changes in residence: Moving to a different ZIP code or county
Other qualifying events: Becoming a U.S. citizen or experiencing income changes affecting your coverage
Unusual or complex situations: Unusual circumstances may include incorrect plan information, insurance agent misconduct, or natural disasters that prevented you from signing up during the open enrollment period.

The Bottom Line

Open enrollment may be the only window to make changes or enroll in a health plan unless you have a qualifying life event. If you miss the open enrollment period and don’t have health insurance, short-term health plans and healthcare-sharing ministries may be able to tide you over until you’re able to enroll in an ACA-compliant health plan. If you qualify, Medicaid and CHIP are also possibilities. You can sign up for them at any time.

Article Sources

Investopedia requires writers to use primary sources to support their work. These include white papers, government data, original reporting, and interviews with industry experts. We also reference original research from other reputable publishers where appropriate. You can learn more about the standards we follow in producing accurate, unbiased content in our editorial policy.

Healthcare.gov. "The Marketplace in Your State."
Healthcare.gov. "Health Coverage for American Indians & Alaska Natives."
Medicare.gov. "Joining a Plan."
Healthcare.gov. "A Quick Guide to the Health Insurance Marketplace."
Healthcare.gov "Medicaid & CHIP Coverage."
Centers for Medicare and Medicaid Services. "Short-Term, Limited-Duration Insurance and Independent, Noncoordinated Excepted Benefits Coverage (CMS-9904-F) Fact Sheet."
Alliance of Health Care Sharing Ministries. "By the Numbers."

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