The Annual Notice of Change is the most important letter you will ignore

Some time in September, a thick envelope arrives from your Medicare Advantage or Part D plan. Most people put it on the pile. It is called the Annual Notice of Change, and it is the plan telling you, in writing and in advance, exactly how it is going to be different on 1 January.

It is the single most useful document in Medicare and it is read by almost nobody.

Why it exists

Advantage and Part D plans are annual contracts. Networks, formularies, copays, deductibles, extra benefits and the maximum out-of-pocket can all change with the new plan year. CMS requires the plan to disclose those changes before the Annual Enrollment Period opens on 15 October, so that you have three weeks to read it and eight to act on it.

The timing is deliberate. The document lands before the window opens because it is meant to inform what you do in the window.

Fifteen minutes, five questions

You do not need to read all of it. Find these five things.

1. Is my monthly premium changing? Usually stated on the first or second page, with this year’s figure next to next year’s.

2. Is the maximum out-of-pocket changing? On an Advantage plan this is your worst case for in-network Part A and B care. If it has moved upward, your exposure has moved with it.

3. Are my drugs still covered, on the same tier? The notice includes a summary of formulary changes. Check each of your prescriptions individually. A tier change is a price change.

4. Are my doctors still in the network? The notice will say whether there have been significant provider changes, but it will not list every departure. If a specialist matters to you, ring their office in October and ask directly.

5. Have the extra benefits changed? Dental allowances, over-the-counter cards, hearing aid benefits and transport benefits are the most volatile part of an Advantage plan and the least regulated.

What to do with the answers

If nothing material has changed and you were happy this year, do nothing. Doing nothing is a legitimate outcome and your plan renews automatically.

If something has changed and you are not happy, you have until 7 December to move, with the change taking effect on 1 January. Inside that window you can switch between Original Medicare and Advantage in either direction, change Advantage plans, or join, change or drop a Part D plan.

If you are in an Advantage plan and only realise in February, you still have the Medicare Advantage Open Enrollment Period from 1 January to 31 March — one move, to a different Advantage plan or back to Original Medicare with a standalone Part D plan. It runs one way only: you cannot use it to move from Original Medicare into Advantage.

The trap in a quiet year

The years people get caught are the years nothing was wrong in October. Delphine’s rheumatologist left the network on 1 January; in October there had been nothing to react to. She had the Advantage Open Enrollment Period and used it, but she used it under time pressure rather than with a shortlist.

Reading the notice does not prevent that entirely — a network can change after the notice goes out. It does mean you are choosing from a position of information rather than from a position of surprise.

One filing habit

Keep the last two Annual Notices of Change. When a plan’s premium or maximum out-of-pocket has moved in the same direction three years running, that is a trend rather than an event, and it is worth acting on before the fourth.