Hold harmless: where the Part B increase gets capped
Section 1839(f) of the Social Security Act does something narrow and useful: where the Part B premium is withheld from a Social Security payment, the premium increase cannot be larger than that person’s dollar cost-of-living adjustment. The net payment cannot fall year over year.
2026 break-even monthly benefit
$639.29
Below roughly this amount, the 2.8% adjustment produces less than the +$18 premium increase, and the cap binds.
- Premium increase
- +$18$185.00 to $202.90
- Adjustment
- 2.8%for 2026
- Break-even benefit
- $639.29continuous arithmetic
- Integer boundary
- $643$642 still binds
The break-even, and the boundary that is not quite the same thing
The continuous arithmetic is simple: divide the premium increase of +$18 by the adjustment of 2.8% and you get $639.29. That is the benefit at which the dollar adjustment exactly equals the premium increase.
The integer boundary sits a little higher, and this is the kind of detail that separates a computed answer from an asserted one. Monthly benefit amounts are floored to the whole dollar before anything compares them. A $642 benefit becomes $659 — an increase of +$17, still short of $17.90, so the cap binds. A $643 benefit becomes $661 — an increase of +$18, which clears it. The real boundary is between those two dollars, not at $639.29.
What the cap actually does, at three amounts
| Monthly benefit | Dollar adjustment | Premium without the cap | Premium charged | Net payment |
|---|---|---|---|---|
| $500 | +$14 | $202.90 | $199.00 | $315 |
| $600 | +$16 | $202.90 | $201.00 | $415 |
| $700 | +$19 | $202.90 | $202.90 | $516 |
On the 46-rung benefit ladder this site publishes, 2 rungs are protected: $500 and $600. That list is computed from the year’s own figures every build. It is never hardcoded, because the break-even moves with both the adjustment and the premium increase — in a year with a small adjustment it can move up the ladder by hundreds of dollars.
Four ways to lose the protection
- You pay an income-related adjustment. Hold harmless does not apply to anyone in an IRMAA tier, at any income level. The brackets are here.
- You are new to Medicare that year. There is no prior-year payment to protect, so there is nothing to hold harmless against.
- Your premium is not withheld from a Social Security payment. If you pay Medicare directly, the provision has nothing to attach to.
- You are not drawing Social Security yet. Same reason.
A note on how this is calculated here
The dollar adjustment used for the cap is the difference between the two floored monthly benefit amounts — what SSA actually compares — not the unfloored percentage increase. On a $600 benefit that is the difference between a capped premium of $201.00 and $201.80, and the floored figure is the correct one.
Common questions
Does hold harmless cap the premium or the increase?
The increase. The premium is capped at the prior year's standard premium plus the beneficiary's own dollar cost-of-living adjustment — so the protected premium is different for every benefit amount, and it rises each year rather than freezing.
Who is not protected?
Four groups. Anyone paying an income-related adjustment; anyone new to Medicare that year; anyone whose premium is not withheld from a Social Security payment; and anyone not yet drawing Social Security. The protection attaches to the withholding, not to the person.
Did hold harmless suppress the 2026 standard premium?
No. The 2.8% adjustment was large enough that only benefits below about $639.29 a month were affected, which is a small part of the population and nowhere near enough to shift the standard premium the way a near-zero adjustment year does.
How many people does it protect?
This site does not publish a number. The Federal Register notice gives no estimate, and the secondary sources contradict each other by millions. The break-even benefit amount is derived arithmetic and is safe to publish; a headcount is not.
Related
- Part B premiumsevery year
- IRMAA bracketsblocks the protection
- When the premium exceeds the checkthe bottom
- Your amountcalculator
- The 2026 COLA2.8%
- SSIno premium deducted
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
- Federal Register — Medicare Program; Medicare Part B Monthly Actuarial Rates, Premium Rates, and Annual Deductible Beginning January 1, 2025 — verified 10 August 2026
- SSA Office of the Chief Actuary — Cost-of-Living Adjustments — 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