The Direct Answer: Work the Checklist in Order
Most people lose money during open enrollment in one of two ways: they auto-renew without reading what changed, or they pick a plan on the premium alone. Both mistakes are avoidable. The checklist below is the order that matters, because each step feeds the next: the ANOC tells you what changed, the drug run tells you what your drugs cost under each option, the doctor check kills plans that fail your non-negotiables, and the total-cost comparison picks the winner.
Start with the calendar. The dates do not move.
The 2027 Open Enrollment Calendar
- By September 30, 2026: your current plan mails the Annual Notice of Change (ANOC). If you threw it away, request another copy from your plan.
- October 1, 2026: 2027 plan details become visible on medicare.gov/plan-compare.
- October 15, 2026: open enrollment opens. You can join, switch, or drop Medicare Advantage and Part D plans.
- December 7, 2026: open enrollment closes. This is a hard deadline.
- January 1, 2027: new coverage takes effect.
- January 1 to March 31, 2027: the Medicare Advantage open enrollment period, for people already in an Advantage plan who want to switch plans or return to Original Medicare. It does not help everyone, so do not plan around it.
Step 1: Read Your ANOC Like a Contract
The Annual Notice of Change is the most important mail your plan sends you all year. It is also the most ignored. Open it and look for five things: the 2027 premium, the deductible, the drug formulary (which drugs are covered and in which tier), the provider network, and the out-of-pocket maximum. Plans change formularies and networks every year. The plan you joined is not necessarily the plan you are renewing into.
If any of your regular drugs moved to a higher tier or off the formulary, that alone can be worth more than the premium difference between plans. Circle it.
Step 2: Run Your Exact Drug List Through Plan-Compare
This is the step that separates a real comparison from a guess. Go to medicare.gov/plan-compare, enter your ZIP, your exact drugs with dosages, and your preferred pharmacy. The tool shows your estimated total annual drug cost under each plan, including tiers.
Two numbers matter here. First, the Part D out-of-pocket cap for 2026 is $2,100 per year: once your covered drug spending hits it, you pay $0 for covered drugs the rest of the year. If you take expensive drugs, this cap is your biggest protection. Second, the maximum Part D deductible for 2026 is $615. Both figures come from the Inflation Reduction Act changes, and both are verified CMS numbers, not estimates.
Step 3: Confirm Your Doctors for 2027
If you are in or considering a Medicare Advantage plan, confirm that every doctor and specialist you actually see is in-network for 2027. Networks change. Do this for each plan you are considering, not just the one you have now. Out-of-network care under most Advantage plans costs you the full bill or is not covered at all.
With Original Medicare plus Medigap, this step barely matters: you can see any doctor who accepts Medicare nationwide. That is one of the main things the higher Medigap premium buys.
Step 4: Compare Total Annual Cost, Not the Premium
The monthly premium is the least informative number on the page. Compare two numbers for each option: a quiet year (premiums plus your routine costs) and a rough year (premiums plus the plan's out-of-pocket maximum). Medicare Advantage often wins the quiet year and loses the rough year. Original Medicare plus Medigap Plan G costs more every month but barely moves between the two: after the $283 Part B deductible, Plan G pays nearly all cost-sharing.
Use our Medicare cost calculator for the annual estimate, then read our Advantage vs Medigap cost scenarios guide for the quiet-year and rough-year walkthrough. If you want the comparison personalized to your situation, the AI Medicare Advantage vs Medigap explainer does it from your inputs.
Step 5: Check the Underwriting Question Before You Switch Paths
This is the step people learn about one year too late. If you are thinking of leaving Medicare Advantage for Original Medicare plus Medigap, know this: in most states, Medigap insurers can use medical underwriting once your one-time Medigap open enrollment window (at 65, when you first enroll in Part B) has passed. That means they can charge you more or deny you based on health.
A few states have birthday rules or broader guaranteed-issue rights that protect you. Check your state's rules before you disenroll from Advantage. Do not give up a guaranteed-issue right you cannot get back.
Step 6: Make Sure Late Penalties Do Not Apply to You
If you delayed Part B or Part D because you had employer coverage, confirm that coverage counted as creditable. The penalties for getting this wrong are permanent: Part B costs 10% more for every full 12-month period you were late, for life, and Part D costs 1% of the base premium per month late, for life. One phone call to your former employer's benefits office or to 1-800-MEDICARE settles it.
Step 7: Book a Free SHIP Counselor Early
State Health Insurance Assistance Programs (SHIP) provide free, unbiased Medicare counseling in every state. The counselors do not sell insurance and take no commissions. They will walk through your ANOC, your drugs, and your options with no sales pitch.
Book early in open enrollment because appointments fill up. Bring your Medicare card, your complete drug list with dosages, your ANOC, and your doctors' names. Our AI Medicare decision companion builds a one-page printable report of your situation, the verified figures, and your personalized guidance that you can hand the counselor.
Step 8: Enroll by December 7 and Confirm in Writing
Make the change through medicare.gov, 1-800-MEDICARE, or the plan directly, and get written confirmation with the effective date of January 1, 2027. If you disenroll from a plan, confirm the end date too, so you do not end up double-covered or uncovered in January. Keep the confirmation with your ANOC.
Verified 2026 CMS Figures Referenced Above
These are the current national figures announced by CMS in November 2025. 2027 figures arrive in November 2026. Verify anything plan-specific at medicare.gov, because your plan's numbers control.
- Part B premium: $202.90/month (standard; higher earners pay more through IRMAA)
- Part B deductible: $283/year
- Part A deductible: $1,736 per benefit period
- Part D maximum deductible: $615
- Part D out-of-pocket cap: $2,100/year
- Medigap Plan G: pays nearly all cost-sharing after the $283 Part B deductible
7 Mistakes That Cost Real Money
- Auto-renewing without reading the ANOC. Your plan's 2027 version can have a different formulary, network, and premium. Doing nothing is a choice.
- Shopping on premium alone. A $0 premium plan with a high out-of-pocket maximum and your drugs on a bad tier is the most expensive plan you can buy.
- Skipping the drug run. Tiers change yearly. Five minutes on plan-compare with your exact drugs beats an hour of brochure reading.
- Assuming your doctors are still in-network. Networks change. One out-of-network surgery wipes out years of premium savings.
- Leaving Advantage for Medigap without checking underwriting. In most states you cannot count on getting back into Medigap later at a good price.
- Ignoring the Part D cap. The $2,100 out-of-pocket cap is the strongest protection expensive-drug users have. Know whether your plan honors it the way you expect.
- Waiting until December to book SHIP. Free counselors are busiest the last two weeks. Early November gets you a real appointment.
Frequently Asked Questions
When is Medicare open enrollment for 2027 coverage?
October 15 through December 7, 2026. Changes take effect January 1, 2027. The Medicare Advantage open enrollment period (January 1 to March 31) is a limited second chance for people already in an Advantage plan, not a substitute for the main window.
What is the Annual Notice of Change and when does it arrive?
Your plan must mail it by September 30 each year. It lists exactly what changes for next year: premium, deductible, drug formulary, and provider network. Read it before open enrollment, because the 2027 version of your plan may differ from the one you joined.
What should I check during Medicare open enrollment?
In order: your ANOC, your exact drug list on medicare.gov/plan-compare, your doctors' 2027 network status, total annual cost (quiet year and rough year), Medigap underwriting rules if you are switching paths, and a free SHIP appointment before you decide. The AI Medicare decision companion walks through all of this from your answers.
What happens if I do nothing during Medicare open enrollment?
If you are in Original Medicare, nothing changes. If you are in an Advantage or Part D plan, you are usually auto-renewed into next year's version, which can have different premiums, drugs, and doctors. Review the ANOC even when you plan to stay put.
Is SHIP counseling really free?
Yes. State Health Insurance Assistance Programs counsel in every state, free and unbiased, with no insurance sales. Find yours through medicare.gov or by searching for your state's SHIP. Bring your drug list, your ANOC, and your doctors' names. Appointments fill up, so book early.
Should I switch from Medicare Advantage to Medigap?
Maybe, but check underwriting first. In most states, leaving Advantage for Medigap after your initial open enrollment window means insurers can underwrite you: higher prices or denial based on health. Our how-to-choose guide walks through the full tradeoff, and the decision companion personalizes it.
Does Medicare cover dental, vision, and hearing?
Original Medicare does not routinely cover them. Many Advantage plans bundle limited dental, vision, and hearing benefits. If these matter to you, price them into the comparison rather than discovering the gap at the dentist.
What is the Part D out-of-pocket cap?
$2,100 per year for 2026. Once your covered drug spending reaches the cap, you pay $0 for covered drugs for the rest of the year. It is the single biggest drug protection the Inflation Reduction Act added.