Open Enrollment and Your GLP-1 Coverage: How to Compare Plans Before You Switch
Medicare, Marketplace, and employer open enrollment windows overlap every fall. Here's what to actually check on a plan's formulary before you pick it for the year ahead.
- ✓Medicare Open Enrollment runs October 15 – December 7 each year for coverage starting January 1; Marketplace Open Enrollment generally runs November 1 – January 15.
- ✓Employer open enrollment windows are set individually — check with HR or your benefits portal for your specific dates.
- ✓A plan “covering” your GLP-1 and covering it without a new prior authorization are two different questions — check both before you enroll.
- ✓A prior authorization approved under your current plan generally does not carry over to a new plan, even with the same insurer.
- ✓If your current Medicare plan is changing for next year, your insurer must send an Annual Notice of Change (ANOC) by the end of September — read it before assuming your coverage stays the same.
- ✓A lower premium isn’t automatically the better deal if it comes with a higher specialty-drug tier or a reset PA process.
- ✓Outside open enrollment, you generally need a Special Enrollment Period (job loss, move, other qualifying event) to change plans.
Why Open Enrollment Matters More When You Take a GLP-1
For a lot of people, open enrollment is a five-minute task: confirm the plan renews automatically, maybe glance at the premium, move on. That shortcut is riskier if you’re on a GLP-1 prescription, because these medications are frequently brand-name only, commonly require prior authorization, and sit on specialty or high cost-sharing tiers on many formularies. A plan that looks similar to your current one on price can differ substantially on whether it covers your specific medication, at what tier, and with what process attached — and open enrollment is the window where you have the standing to actually compare and switch, without needing a qualifying life event.
The Overlapping Enrollment Windows, and Which One Applies to You
- Medicare Open Enrollment (Annual Enrollment Period): October 15 through December 7 each year, with changes taking effect January 1. This is when Medicare beneficiaries can switch Part D prescription drug plans, switch between Medicare Advantage and Original Medicare, or change Medicare Advantage plans.
- ACA Marketplace Open Enrollment: generally November 1 through January 15 in most states that use the federal Marketplace (some state-run marketplaces set their own dates). This applies if you buy your own coverage rather than getting it through an employer or Medicare.
- Employer open enrollment: dates are set by each employer, typically sometime in the fall, and often run for a shorter window than the government programs above. Check your HR department or benefits portal for your specific dates — there’s no single federal date that applies to every employer plan.
These windows can overlap on your calendar even though they govern completely different types of coverage — it’s worth confirming which one (or ones) actually apply to your situation before you start comparing plans.
What to Check on a Plan Before You Pick It
- Is your specific medication on the formulary at all? Search the plan’s drug list by the exact brand name you take — GLP-1 medications in the same class aren’t interchangeable on a formulary the way generics often are.
- What tier is it on? Specialty and top tiers usually carry higher coinsurance or copays than lower tiers. A plan that technically covers your drug on its highest tier can still leave you with a large monthly cost.
- Does it require prior authorization or step therapy? Being listed on a formulary doesn’t mean automatic coverage — many plans require a new PA request, and some require you to try and fail a different medication first (step therapy) even if you’re already stable on your current one.
- Is your specialty pharmacy in-network? Some plans route specialty medications through a specific specialty pharmacy. If your current pharmacy isn’t in that network, switching plans can also mean switching where you fill.
- What’s the deductible and out-of-pocket structure for specialty tiers specifically? A plan’s overall deductible number doesn’t always tell you what a specialty-tier drug will actually cost you before and after that deductible is met.
Using the Official Plan Comparison Tools
For Medicare, the Medicare Plan Finder at Medicare.gov lets you enter your specific medications and pharmacy to see estimated costs and formulary status across plans available in your area — it’s built specifically to answer the formulary-and-cost question rather than requiring you to read each plan’s drug list PDF by hand. For Marketplace plans, HealthCare.gov’s formulary lookup works similarly during your state’s enrollment window. For an employer plan, your benefits portal or HR department can usually provide plan-specific formulary documents — ask directly for the drug list (formulary) for each plan option, not just a benefits summary, since summaries often don’t list individual drug tiers.
If Your Current Plan Is the One Changing
Open enrollment isn’t only relevant if you’re actively shopping — your current plan can change under you even if you do nothing. Medicare Part D and Medicare Advantage plans are required to send an Annual Notice of Change (ANOC) by the end of September, describing changes to costs, coverage, provider networks, service area, and the formulary for the coming year. Read it specifically for your GLP-1 medication’s tier and PA status — a plan that covered your drug this year can move it to a higher tier or add a new PA requirement for next year without switching plans being your choice at all. If you find your current plan is changing in a way that affects your coverage, our guide on what to do when your insurance changes covers the steps to take before the new terms take effect.
A Caveat: When Switching for a Lower Premium Isn’t the Better Deal
It’s tempting to treat open enrollment as a simple price-shopping exercise, and for people without an expensive prescription, that’s often fine. It’s a different calculation if you’re already stable on a GLP-1 with an approved prior authorization. A prior authorization is generally tied to a specific plan and plan year — switching plans, even to a cheaper one from the same insurer, commonly means starting the PA process over with your new plan, which takes time and isn’t guaranteed to approve on the same terms. A modest premium saving that comes with weeks of PA processing, a higher specialty-drug copay, or a forced pharmacy switch can cost more in total than staying on a slightly pricier plan that already has your medication approved and your pharmacy relationship intact. Run the comparison on total expected cost and hassle, not premium alone, before you switch a working setup.
If You’re Choosing Between Employer Plan Options
Many employers offer more than one plan tier (for example, a high-deductible plan alongside a PPO). The formulary and specialty-drug tier structure can differ between these options even though they’re offered by the same employer and, often, administered by the same insurer. Ask your HR department for the specific drug formulary for each plan option — not just the summary of benefits and coverage — and confirm prior authorization requirements for your specific medication under each one before you enroll.
Special Situations That Change the Timeline
If you’re navigating a job loss rather than a routine annual renewal, the mechanics and deadlines are different — you’ll generally be choosing between COBRA and a Marketplace Special Enrollment Period on a strict 60-day clock, not the fall open enrollment window described above. See our guide on GLP-1 coverage after losing your job for how that decision works. If you’re aging into Medicare and weighing Part D coverage for the first time, our guide on the Medicare GLP-1 Bridge program covers how that temporary coverage differs from a standard Part D prior authorization.
A Pre-Decision Checklist
- Confirm which enrollment window applies to you (Medicare, Marketplace, or employer) and its exact dates.
- Read your current plan’s Annual Notice of Change (if applicable) for next year’s formulary and tier changes.
- Search each plan option’s formulary by your medication’s exact brand name, not just its drug class.
- Note the tier and whether prior authorization or step therapy is required for each option.
- Confirm your specialty pharmacy is in-network for any plan you’re considering switching to.
- Compare total expected annual cost — premium plus specialty-tier cost-sharing — not premium alone.
- If switching, alert your prescriber’s office early so a new PA request can be submitted before your old coverage ends.
Frequently Asked Questions
When is open enrollment if I take a GLP-1 medication?
It depends on your coverage type. Medicare Open Enrollment runs October 15 – December 7. Marketplace Open Enrollment generally runs November 1 – January 15. Employer windows are set by each employer — check with HR.
What should I check on a new plan’s formulary before switching?
Whether your specific medication is listed, what tier it’s on, and whether prior authorization or step therapy is required. Coverage and easy coverage are different questions.
Does my current prior authorization carry over if I switch plans?
Generally no — expect to need a new PA request with the new plan, and build in time for it to process.
Is switching plans during open enrollment always worth it for a lower premium?
Not automatically. Factor in tier placement, PA reset, and pharmacy network changes, not just the premium.
What if I miss my open enrollment window?
You generally need a Special Enrollment Period, triggered by an event like job loss or a move, to change plans outside the standard window.