When the Medicare premium is announced, and the month-long gap it creates
Two numbers decide what lands in a January payment. They are announced about a month apart by two different agencies, and for that month the arithmetic is deliberately incomplete.
The gap between the two announcements
about a month
The cost-of-living adjustment lands with the September Consumer Price Index in mid-October. The following year’s Part B premium lands in mid-November.
- Adjustment announced
- mid-October14 October 2026 this year
- Premium announced
- mid-Novemberabout a month later
- First payment affected
- January 2027
- Open enrolment
- 15 Oct – 7 Decstraddles both
The two-step calendar
| When | What is published | What can be computed |
|---|---|---|
| Through the summer | Monthly Consumer Price Index releases | A projection of the adjustment, with the assumption stated |
| Mid-October | September index, then the adjustment and programme parameters | The gross benefit for the coming year, exactly |
| Mid-October to mid-November | Nothing further on the premium | Gross only. A net figure would require guessing the premium, and this site does not |
| Mid-November | Part B premium, deductible and income-related brackets | The net payment, exactly |
| January | — | The first payment carrying both changes |
Why the gap is uncomfortable
The adjustment is the headline and the premium is the thing that decides how much of it survives. In 2026 the 2.8% adjustment added +$56 a month to a $2,000 benefit; the premium increase of +$18 took 31.96% of it back. Between the two announcements, everyone knows the first number and nobody knows the second.
That is also the window in which most bad estimates get published. A premium figure invented in late October has no data behind it — the actuarial rate that produces it is not public until CMS publishes it.
What this site does in that window
Class B pages render the 2027 gross benefit with the assumption printed alongside it, and state explicitly that the 2027 Part B premium has not been announced. The 2026 net figure is shown for comparison. The 2027 premium is never estimated, and the record for it stays marked as pending until the Federal Register notice exists.
Where the numbers come from
The premium, deductible and bracket tables on this site are read from the annual Federal Register notice — the legally operative text — retrieved through govinfo. That choice is practical as well as principled: cms.gov blocks automated retrieval outright, and PDF mirrors of CMS fact sheets have been observed to parse into plausible, well-formed and entirely wrong tables carrying figures from an earlier year. A wrong table that parses cleanly is worse than one that fails.
22 years of Part B premiums are published here, each with its own notice. The full series.
The enrolment window sits across both
Medicare’s annual enrolment period runs from 15 October to 7 December — opening the day after the adjustment is typically announced and closing weeks after the premium is. For most of it, one of the two numbers that determine next year’s payment is public and the other is not.
The 2027 adjustment itself is not decided yet: 0 of the three third-quarter months are published. The projection, with each assumption stated.
Common questions
When will the 2027 Medicare Part B premium be announced?
CMS has announced the following year’s Part B premium, deductible and income-related brackets in mid-November in recent years, published formally in the Federal Register shortly afterward. Treat mid-November as the expected window rather than a fixed date.
Why is it a month after the COLA?
They are separate determinations by separate agencies on separate data. The adjustment needs the September Consumer Price Index; the premium needs the actuarial rate for the coming year, which is a projection of programme costs. Neither depends on the other, and the premium calculation is the slower of the two.
Can I estimate my 2027 net payment now?
Not honestly. The gross figure can be projected from published index data with the assumption stated. The premium cannot be projected at all from public data, so a net figure would be a guess wearing a calculation’s clothes. This site publishes gross and says so.
Does the premium announcement change the COLA?
No — except at the very bottom of the benefit range, where the hold-harmless provision caps the premium increase at the beneficiary’s own dollar adjustment. In a near-zero adjustment year that interaction can hold the premium down for most beneficiaries and push it up sharply for the minority not protected.
Related
- COLA timingmid-October
- Part B premiums22 years
- 2027 projectiongross only
- The net raisethe study
- IRMAA bracketsannounced together
- Part A coststhe same notice week
Sources and freshness
- Federal Register — Medicare Program; Medicare Part B Monthly Actuarial Rates, Premium Rates, and Annual Deductible Beginning January 1, 2026 — verified 10 August 2026
- BLS — Consumer Price Index release schedule — verified 10 August 2026
Figures effective 1 January 2026. Page figures last verified against the sources above on 10 August 2026. Corrections: the correction log · support@inventum.com.au