Medicare Part D

That fall envelope from your Part D plan? Don't toss it.

In Bolingbrook, the mail that lands in Part D members' boxes each September is easy to mistake for junk. It isn't. The Annual Notice of Change, or ANOC, is the single document that tells you what your drug plan will look like on January 1, 2027 — and what to do before the December 7 deadline if you don't like what you see.

Drug plans are allowed to change their formularies (the list of covered drugs) from one year to the next. A medication that sat on a low tier in 2026 can move up a tier, require prior authorization, or come with a new quantity limit in January 2027. The ANOC is where those changes are spelled out, side by side with what you have today.

What the ANOC actually is

The ANOC is a plain-language document your Part D or Medicare Advantage plan is required to send each fall. It lays out what is changing for the coming plan year: the premium, the deductible, the pharmacy network, and — the part that matters most for many readers — the drug list.

If you take even one prescription regularly, the ANOC is worth 20 minutes of your time. Read it with your current pill bottles in front of you.

Four ways a drug's coverage can shift

Plans use a handful of tools, sometimes called utilization management, to shape how drugs are covered. Any of them can appear (or disappear) between plan years:

• Tier changes. Formularies group drugs into tiers, usually 1 through 5. A drug that moves from a lower tier to a higher one generally costs the member more out of pocket.
• Prior authorization. The plan requires your prescriber to get approval before the drug is covered. New PA rules can appear on drugs that had none the year before.
• Step therapy. The plan asks you to try one drug (often a lower-cost alternative) before it will cover another.
• Quantity limits. The plan caps how much of a drug it will cover in a given time period — for example, a set number of pills per month.

A drug can also be removed from the formulary entirely, though plans must give advance notice and follow federal rules when they do.

How to read your ANOC in 20 minutes

Start with the section that compares this year's costs and rules to next year's. Then:

1. Make a list of every prescription you fill, including doses. 2. Find each one in the plan's 2027 formulary (usually included or linked in the ANOC packet). 3. For each drug, note the tier, and check for the letters PA (prior authorization), ST (step therapy), or QL (quantity limit). 4. Compare that to what you have today.

If anything important changes — a drug moves to a higher tier, or a new restriction appears — you have options during the Annual Enrollment Period, October 15 through December 7.

The Bolingbrook picture

Bolingbrook is in Will County, where Medicare beneficiaries generally have a wide range of stand-alone Part D plans and Medicare Advantage plans that include drug coverage. Availability and specifics are set at the county level, not the city level, so two neighbors on the same street see the same menu of choices. What differs is which plan fits which person's drug list — which is exactly why the ANOC comparison matters.

You can compare plans available in your ZIP code using the official Plan Finder at medicare.gov, which lets you enter your prescriptions and see how each plan would treat them in 2027.

2027 rules worth knowing

A few program-wide facts to keep in mind as you read your ANOC:

• The Part D out-of-pocket cap is $2,400 in 2027 (it is $2,100 in 2026). Once you hit it, you pay nothing for covered drugs the rest of the year.
• The maximum Part D deductible is $615, though plans may set it lower.
• The old coverage gap (the "donut hole") was eliminated in 2025. Part D now has three phases.
• The Medicare Prescription Payment Plan lets you spread your drug costs across the calendar year in monthly installments, at no added cost. You have to opt in.
• If your income is above $109,000 (single filer, based on 2024 tax return), an IRMAA surcharge is added to your Part D premium.

What if you're mid-treatment on January 1?

New members and continuing members whose drugs are dropped or restricted are generally entitled to a transition fill — usually a one-time, roughly 30-day supply of the affected drug early in the plan year. That gives you time to work with your prescriber on either a formulary exception request or a switch to a covered alternative. Ask your plan how its transition policy works; the rules are federal, but the process is plan-by-plan.