When Is Open Enrollment 2027? Complete US Timeline Guide

ACA (Affordable Care Act) open enrollment 2027 starts on November 1, 2026, and ends on January 15, 2027. But if you’re on Medicare, your window is different. Open enrollment is the only time of the year when you can sign up for a health insurance plan or change your existing plan. In the fall, most Americans have one question in mind: When is open enrollment for health insurance? Understanding open enrollment 2027 helps you compare plans, make changes to your existing plans, avoid coverage gaps, and make confident decisions for the year ahead. 

If you buy your own health insurance via the Affordable Care Act’s Health Insurance Marketplace, you must be aware of when open enrollment is in 2027, because it's the main time to enroll, renew, or switch marketplaces. 

Miss it, and you have to wait until open enrollment in 2028 unless you qualify for a Special Enrollment Period (SEP). For 2027, most states follow the federal schedule, and some states have even extended their deadlines. This 2027 open enrollment guide covers the complete US timeline, what you can sign up for, and when coverage begins. 

TL;DR

• Open enrollment 2027 starts on November 1, 2026, and ends on January 15, 2027, in most states.
• You must enroll by December 15, 2026, for coverage starting on January 1, 2027.
• If you enroll by January 15, 2027, your coverage will start on February 1, 2027.
• Medicare open enrollment for 2027 runs from October 2026 to December 7, 2026. 
• Medicare Advantage’s second window runs from January 1, 2027, to March 31, 2027. 
• State-specific open enrollment dates vary.
• Before November 2026, find your renewal notice and list your doctors and prescriptions.
• Usually, these timelines match federal Marketplace rules from recent enrollment years. The Centers for Medicare and Medicaid Services (CMS) confirms the exact date each fall. 

If You’re in a Rush, Open Enrollment 2027: Key Dates at a Glance

If you don’t have time to read this entire guide, bookmark this table and come back whenever you need it. 

What is Open Enrollment?

Open enrollment is the specific period each year when individuals can enroll in new health insurance plans or make changes to their existing health insurance coverage. During this time period, individuals can:

• Sign up for a new health insurance plan
• Renew or change your existing plan
• Add or remove dependents
• Switch between coverage options

If you miss the open enrollment period, you can only change coverage if you qualify for a special enrollment period. 

When is Open Enrollment for Health Insurance 2027?

Health insurance open enrollment 2027 runs from November 1, 2026, to January 15, 2027, in most states that use the federal health insurance marketplace. It gives you about 10 weeks to pick a plan. 

If you enroll by December 15, 2026, your coverage starts on January 1, 2027. For individuals who enroll between December 16, 2026, and January 15, 2027, coverage starts on February 1, 2027. 

So, if you want zero gap in coverage, you should aim for the December 15 deadline. Don’t wait until the last week.

State-Specific Federal Open Enrollment Period

The table below shows the 2027 OEP dates for the states that use the federal Health Insurance Marketplace. Coverage begins on January 1. 

Some States Have Different Dates

Not every state follows the same calendar. Some states run their own marketplaces and set their own windows. Here are some states that have different dates. 

Source: Link

So, the rule of thumb is to always double-check your state’s exchange website. Don’t assume the federal dates apply to you if your state runs its own marketplace. 

Medicare Open Enrollment 2027 Timeline

Medicare and the ACA Marketplace work on completely different schedules. Medicare’s Open Enrollment Period runs from October 15, 2026, to December 7, 2026. If you make any changes, they will take effect from January 1, 2027. 

During this window, you can:

• Switch from Original Medicare to a Medicare Advantage plan
• Switch from Medicare Advantage back to Original Medicare
• Change your Part D prescription drug plan
• Choose a new Medicare Advantage plan if yours isn't working for you

Medicare Advantage Open Enrollment Period

If you are already in a Medicare Advantage plan, you get a second chance to switch: the Medicare Advantage Open Enrollment Period, from January 1 to March 31, 2027. This window is more limited. 

You can only switch Medicare Advantage Plans or move back to Original Medicare. You can’t use it to join Medicare Advantage for the first time. 

So, remember these two windows: 

• October 15 to December 7: The big window that is open to everyone on Medicare.
• January 1 to March 31: A smaller window, only for people who are already in Medicare Advantage. 

What If You Miss The Open Enrollment Window?

You got busy, forgot, or maybe you just didn’t know the deadline existed. So, what now? 

Outside of open enrollment, you normally can’t sign up for or change ACA Marketplace coverage. The same goes for Medicare’s main window. 

But there is an exception: the Special Enrollment Period (SEP). This opens if you have a qualifying life event, such as

• Losing your job (and your health coverage with it)
• Getting married or divorced
• Having a baby or adopting a child
• Moving to a new state
• Losing other coverage, like a parent's plan when you turn 26

If one of these applies to you, you get 60 days from the event to enroll in a new plan. So, don’t worry if you miss the open enrollment unless you have one of these qualifying events. 

How to Prepare Before Open Enrollment Starts

The best way to avoid this stress is to get ready before the window opens. You should follow this simple checklist:

• Review your current plan - Check whether your premiums are going up or your doctors are still in-network. 
• Compare your options - Look at premiums, deductibles, and what subsidies you might qualify for.
• Know where to shop - Use Healthcare.gov , your state's exchange, or Medicare.gov , depending on your situation.
• Set a reminder - Put the start date and your personal deadline on your calendar now.

Let’s understand what open enrollment looks like in real life with a simple example. 

Ema’s ACA plan renews every year, so here is her simple timeline:

• October 1, 2026 - She reviews her current plan and notices her premium is going up.
• October 20, 2026 - She compares three new plans on the marketplace.
• November 10, 2026 - She chooses a plan and enrolls.
• January 1, 2027 - Her new coverage kicks in, with no gap at all.

Ema didn't wait until the last minute, and she didn't rush. She gave herself a few weeks to think properly and make the right decision.

Open Enrollment 2027 Timeline: Summary

Whenever you’re in doubt, check your own state’s exchange or Medicare.gov for the exact date that applies to you. If you are an insurance agent and want to learn how you can increase lead generation during open enrollment , we have covered it in our latest blog. 

Final Thoughts

Open enrollment dates can be easy to lose track of because there are different windows for Medicare, the Health Insurance Marketplace, and individual states. Once you know your dates, the rest is just a matter of comparing plans and choosing what fits. 

If you’re an insurance agent, staying on top of your client’s deadline is quite challenging, especially when everyone’s enrollment window looks a little different. This is where Textdrip helps. Using Textdrip, insurance agents can set up automatic SMS reminders for each client’s personal enrollment deadline. So, no one misses their window, and no leads go cold. Book a free Textdrip demo to see how easy it is to keep your clients on track this open enrollment 2027 season.