About Advantage Index

We publish the Medicare plan data the government already publishes, arranged by county, so that it can be read. That is the whole of it.

What this is not

• Not affiliated with Medicare, CMS, or any insurance plan. Nobody here is connected to the federal government or to any insurer, and nothing on this site is endorsed by either.
• Not an insurance agent or broker. We are not licensed to sell insurance, we cannot enrol you in anything, and we are not paid by any plan or agency for what you do after you leave. There is no quote tool and no enrolment form on this site, by design.
• Not advice. Which plan suits you depends on your doctors, your prescriptions, your health and your finances. None of that is in the data and none of it is knowable from here.
• Not the complete picture. We publish what CMS publishes: price, out-of-pocket maximum, star rating, service area, enrolment, sanctions. What a plan actually covers, which doctors are in its network and which drugs are on its formulary are not on these pages. For all of it, and to enrol, use Medicare.gov or call 1-800-MEDICARE, free, 24 hours a day.

Where every figure comes from

All of it is published by the Centers for Medicare & Medicaid Services, is in the public domain as a work of the federal government, and is reproduced here without alteration. We calculate nothing.

• Premiums, deductibles, out-of-pocket maximums, star ratings, sanctions, service areas — the Medicare Advantage and Part D landscape file, republished by CMS through the year.
• How many people chose each plan in each county — the monthly enrolment file by contract, plan, state and county.
• How many people in a county are eligible for Medicare, and how many are in an Advantage plan — the monthly state/county penetration file.
• What happens to each plan next year — the Part C and D plan crosswalk, published each October.
• Star ratings domain by domain — the Part C and D star ratings data tables.

Three things we will not do to a number

These are the ways data like this is usually made to mislead, and we have written the site so that it cannot.

• An absent figure is shown as absent, never as zero. CMS suppresses any enrolment count of ten or fewer to protect privacy — about 94% of that file. We show “fewer than 11”, because “0” would say nobody in your county chose that plan, which is both false and the opposite of what suppression means.
• A plan with no star rating is not a nought-star plan. CMS marks new plans “too new to be measured”. We print the reason, not a number.
• A county CMS leaves out is said to be left out. CMS withholds a whole state from the monthly enrolment file when its county codes have changed and its own records have not caught up. Those counties keep their plan pages and are shown as having no published enrolment share.

Corrections

If something here is wrong, tell us and we will fix it or remove it — see contact. Where our figure disagrees with CMS, CMS is right and we have a bug.

Published by Ospan, Nevada, USA. Effective 2026-09-17.