The chart exists, Medicare publishes it, and most people read it the wrong way round. Reading down the columns invites the conclusion that the more expensive letters are simply better. Reading across the rows shows what is actually going on: most of the rows are the same for almost every letter, and the decision lives in four of them.
The rows that are the same almost everywhere
Hospital coinsurance and the extra days after Medicare's own benefit runs out, the blood benefit, hospice coinsurance and skilled nursing coinsurance are covered in full by most of the standardised letters, with two exceptions that pay a stated percentage instead. If those rows were all that mattered the choice would barely matter. Reading them first is useful mainly to establish how much of the chart is not the decision.
The four rows that do the work
The Part A deductible, the Part B deductible, Part B excess charges and foreign travel emergency care are where the letters genuinely diverge, and two letters replace the whole question with an annual out-of-pocket limit instead. Those rows are the reason two letters cost different amounts, and because the benefit sets are standardised in federal law they mean the same thing whoever issues the policy, which makes them the only part of a Medigap comparison a reader can do without a quote.
The row whose answer is local
Part B excess charges only arise where providers bill above the Medicare-approved amount, and several states restrict or prohibit that outright. So the letter that covers excess charges is worth more in some states than others, and in a few it is worth very little. That makes this the one row on the chart whose importance a national article cannot tell you, and the state insurance department or the free counselling service is where it gets settled.
Questions people ask about medicare supplement plans chart
Does the chart show prices?
No. It compares what each standardised letter covers. Premiums are set per insurer, per state and per applicant, so no chart could carry them truthfully.
Are the letters really identical between insurers?
The benefit sets are, by federal law. Three states run their own standardisation systems, and Medicare's own pages say so.
Which rows should I look at first?
The deductibles, excess charges and foreign travel rows, plus the out-of-pocket limit on the two letters that carry one. The rest are the same nearly everywhere.
Where is the official chart?
On Medicare.gov, linked below. This page is about how to read it, not a copy of it.