Doing Nothing Is Still a Decision

Is my coverage still right?

Every autumn, most people on Medicare get a thick envelope, glance at it, decide their plan is fine, and do nothing.

That's a decision. It's just one made without looking.

Your plan changes every year, and it doesn't need your permission. Premiums move. Formularies get rewritten. Networks shrink. Deductibles shift. The plan that was the best available for you two years ago may be a poor fit now, entirely without your involvement.

The window is October 15 through December 7. It doesn't extend.

What actually changed this year

There's a genuine improvement worth understanding, because most people haven't caught up with it.

The Part D coverage gap — the "donut hole" — is gone. It was replaced by something much simpler: a hard annual cap on what you can spend out of pocket on covered drugs.

For 2026 that cap is $2,100. Once your out-of-pocket drug spending reaches it, your plan pays 100% of covered prescriptions for the rest of the calendar year.

For anyone taking expensive medication, that's a substantial protection that didn't exist a few years ago. It means the worst case on prescriptions is now knowable in advance.

Two details that matter:

Your premiums don't count toward the cap. Only what you actually pay for drugs — the deductible and your share of costs — counts. People routinely assume premiums count. They don't.

The cap applies only to drugs covered by your Part D plan. A drug that isn't on your plan's formulary doesn't count toward it at all, and you pay full price. Which brings us to the thing that actually deserves your time.

The formulary check is the whole exercise

Every Part D plan and every Medicare Advantage plan with drug coverage keeps its own list of covered medications, sorted into tiers. That list gets rewritten annually.

Between one year and the next, any of your prescriptions can:

Move to a higher tier, so the same drug costs several times more. Acquire a prior authorization requirement, so your doctor has to justify it before the plan pays. Get a quantity limit. Or come off the list entirely, leaving you paying full retail with nothing counting toward the cap.

None of that is announced in a way most people notice. It arrives in that envelope, in small type.

So the exercise is: take your actual list of medications and check each one against next year's formulary for the plans available to you. Medicare's Plan Finder at medicare.gov does exactly this — you enter your drugs and your pharmacy, and it estimates your total annual cost under each plan.

It takes about twenty minutes and it's the single most valuable twenty minutes in this month.

Compare total cost, not premium

The most common mistake is choosing on the premium alone.

A plan with a $0 premium and the maximum allowable deductible can be an excellent deal for someone taking only generics — and considerably worse for someone on brand-name medication. A plan with a higher premium and a rich formulary can cost far less overall.

The number to compare is annual premium plus deductible plus your actual drug costs under that plan's tiers. Nothing else is a comparison.

One useful piece of arithmetic: with the maximum deductible and standard cost sharing, you reach the out-of-pocket cap once your total drug costs run to roughly $6,500 for the year. Above that, every plan's worst case converges — so the formulary and the tiers matter more than anything else.

If you're on Medicare Advantage

Two extra checks, both annual.

The network. Providers leave Advantage networks every year, and it doesn't make the news. Check that your doctors and your preferred hospital are still in network for next year specifically — not this year.

The out-of-pocket maximum. This is the number that defines your worst year. For 2026 the ceiling on in-network costs is $9,250, though most plans set theirs below that. It's the figure to know before you need it.

The other window, and the door that doesn't reopen

If you're on Medicare Advantage, there's a second window from January 1 to March 31 where you can switch to a different Advantage plan or move to Original Medicare. It's one change, and it's narrower than the autumn window.

But the warning from May applies here and it's the most important thing in this brief.

Moving from Advantage to Original Medicare does not guarantee you can buy a supplement. Your guaranteed-issue window for Medigap was the six months after your Part B started. Outside of that, in most states, insurers can medically underwrite you — and decline.

So the switch isn't symmetrical. Going from Original Medicare to Advantage is generally easy. Coming back can leave you on Original Medicare with no supplement and no annual cap on what you spend.

A handful of states require ongoing guaranteed issue. Most don't. If you're considering the move, find out which kind of state you're in first.

Also this month

October is when several numbers get published for next year.

The Social Security cost-of-living adjustment is announced — for 2026 it was 2.8%. Worth noting that the Part B premium increase frequently absorbs a meaningful share of it, so the net increase in your deposit is usually smaller than the headline.

Next year's contribution limits and income thresholds are published too. If you're near a threshold, that's the month you find out where next year's line sits.

If you're under 65

Marketplace open enrollment runs November 1 through January 15, and this year it matters more than usual.

The enhanced subsidies expired, and the hard cutoff at 400% of the federal poverty level is back — roughly $62,600 for a single person and $84,600 for a couple. One dollar over and the credit is zero.

Which means your enrollment decision and your income planning are the same decision. Set your projected income for the application deliberately, and revisit it if anything changes during the year. May's month has the detail.

What October is for

Twenty minutes at medicare.gov with your actual drug list and your actual pharmacy.

Confirm your doctors are in network for next year. Note your plan's out-of-pocket maximum. Compare total annual cost rather than premium.

Then either switch or consciously decide not to. Both are fine. Doing nothing because you never opened the envelope is the one to avoid.

December 7. It doesn't move.