Social Security COLA Calculator
Your benefit before the COLA, and how Medicare is paid
Your result will appear here
Fill in the fields on the left and this updates as you type.
Know what this estimate is based on
- Jurisdiction
- General mathematical model
- Scope and limitations
- Educational estimate only. Confirm the assumptions, current rules, fees, and rounding that apply to your situation before making a decision.
- Source links checked
- Jul 30, 2026
Built and regression-tested by Smart Tools Lab. It has not been individually reviewed by a licensed financial, tax, or legal professional.
How to use
- 01
Find your monthly benefit before the COLA: the gross amount for November 2025, paid in December 2025, before Medicare is taken out. It appears on the notices SSA sends and in your online Social Security account.
- 02
Enter 1 if Medicare Part B comes out of your Social Security check, or 0 if you pay Medicare directly or Medicaid or a state pays it for you.
- 03
If you pay an income-related surcharge (IRMAA) on Part B, open Advanced options and enter it. The 2.8% COLA and the $185.00 and $202.90 Part B premiums are already filled in from SSA and CMS.
- 04
Read the change in your deposit, then the new gross benefit, the Part B increase and the share of the COLA the premium took back.
- 05
Check the hold-harmless stat: it says whether the rule protects your check, whether it would only matter at a smaller benefit, or why it does not cover you.
Formula
New benefit = benefit before the COLA × (1 + COLA), rounded down to the dime. COLA added = new benefit − benefit before the COLA. Deposit = benefit − Part B premium − any IRMAA surcharge, rounded down to the whole dollar; if Part B is not deducted, the deposit is the benefit rounded down to the dollar. Hold harmless, when the premium is deducted and no IRMAA is paid: if the 2026 deposit at the full premium would fall below the 2025 deposit, the 2026 premium becomes the new benefit − the 2025 deposit, never below the 2025 premium and never above the full 2026 premium. Part B increase = 2026 premium charged − 2025 premium. Share of the COLA taken = Part B increase ÷ COLA added. Effect over a year = change in the monthly deposit × 12. The page assumes any IRMAA surcharge was the same in 2025. 2027 estimate = average CPI-W for July and August 2026 ÷ the July to September 2025 average − 1.
Example
A retiree's benefit is $2,000.00 before the COLA, and Part B comes out of the check. The 2.8% COLA makes it $2,000.00 × 1.028 = $2,056.00, already a whole dime, so $56.00 more. In 2025 the deposit was $2,000.00 − $185.00 = $1,815. In 2026 it is $2,056.00 − $202.90 = $1,853.10, paid as $1,853. The deposit rises $38 a month, $456 over the year, and the $17.90 premium rise took 32.0% of the COLA. Hold harmless is not needed, because it binds only below a benefit of about $639.29. At a $600.00 benefit it does: the COLA makes $616.80, the full premium would cut the deposit from $415 to $413, so the premium is held to $201.80 and the deposit stays at $415.
Definitions
- COLA
- The cost-of-living adjustment SSA applies to Social Security benefits each year, equal to the rise in the third-quarter average CPI-W, rounded to the nearest tenth of a percent. For 2026 it is 2.8%.
- CPI-W
- The Consumer Price Index for Urban Wage Earners and Clerical Workers, a BLS index that covers a narrower group of households than CPI-U. The law ties the Social Security COLA to it.
- Part B standard premium
- The monthly premium most people pay for Medicare Part B, which covers doctor visits and outpatient care: $202.90 in 2026 and $185.00 in 2025, per CMS.
- Hold-harmless provision
- Section 1839(f) of the Social Security Act: for people whose Part B premium is deducted from their benefit and who pay no IRMAA, a premium increase cannot make the Social Security deposit smaller than the year before.
- IRMAA
- The income-related monthly adjustment amount, a surcharge on Part B (and Part D) premiums for people whose income two years earlier was above a threshold. In 2026 the first Part B tier adds $81.20 a month above $109,000 of income for a single filer or $218,000 for a joint return.
Good to know
How Social Security's cost-of-living adjustment is set
Social Security benefits rise automatically each year under a formula written into the Social Security Act, so no one decides the COLA; it is calculated. The measure is the Consumer Price Index for Urban Wage Earners and Clerical Workers, CPI-W, which the Bureau of Labor Statistics publishes every month alongside the more familiar CPI-U. The law compares the average CPI-W for July, August and September of the current year with the same three-month average from the last year a COLA took effect. The percentage increase is rounded to the nearest tenth of a percent. If prices did not rise, or the rounded increase is zero, there is no COLA that year, and benefits do not fall. For 2026 the numbers were straightforward. According to SSA, the third-quarter average CPI-W was 308.729 in 2024 and 317.265 in 2025. The increase, (317.265 − 308.729) ÷ 308.729, rounds to 2.8%. The underlying monthly figures from BLS were 316.349 for July 2025, 317.306 for August and 318.139 for September. The adjustment applies to benefits for December 2025, which are paid in January 2026, so the first larger check arrives in the new year. Supplemental Security Income payments rose by the same 2.8% from January 2026. On this page's example, a $2,000.00 monthly benefit becomes $2,056.00, $56.00 more. CPI-W and CPI-U usually move together, but they are not identical. CPI-W is built from the spending of households that earn most of their income from clerical or wage jobs, a narrower group than CPI-U covers, and its weights differ as a result. Retirees often spend more of their budget on health care and housing than the households CPI-W describes, which is why the COLA can feel smaller than the inflation retirees see. The COLA is still one of the few sources of retirement income that rises with prices by law every year.
Where the Medicare Part B premium comes in
For most people who receive Social Security and are enrolled in Medicare, the Part B premium is taken out of the benefit before it is deposited. So the question that matters for a household budget is not how much the benefit rose, but how much the deposit rose once Medicare took its share. The Centers for Medicare and Medicaid Services set the 2026 standard Part B premium at $202.90 a month, up $17.90 from $185.00 in 2025, in its fact sheet of 14 November 2025. The annual Part B deductible rose to $283 from $257. On this page's example, the 2.8% COLA adds $56.00 to a $2,000.00 benefit and the premium rise takes $17.90 of it, 32.0%. The deposit goes from $1,815 to $1,853, up $38 a month and $456 over the year. The premium rise is the same dollar amount for everyone who pays the standard premium, while the COLA is a percentage of the benefit, so the premium takes a larger share of a smaller check. At a 2.8% COLA, the COLA only covers the $17.90 rise for benefits above about $639. Higher-income beneficiaries pay more. The income-related monthly adjustment amount, IRMAA, adds a surcharge based on the modified adjusted gross income on a tax return from two years earlier. For 2026 the first tier adds $81.20 a month, for a total premium of $284.10, when that income is above $109,000 for a single filer or $218,000 on a joint return, and higher tiers add more. People who pay IRMAA see the same $17.90 rise in the standard part of their premium, and they lose the protection described in the next section. Anyone whose premium is paid some other way, by billing or by a state Medicaid program, receives the whole COLA in the deposit but still faces the higher premium through that other route.
The hold-harmless rule, and who it leaves out
Section 1839(f) of the Social Security Act, often called the hold-harmless provision, prevents a Medicare premium increase from shrinking a Social Security check. The statute sets three conditions. The person must have been entitled to Social Security benefits for November and December of the prior year. The Part B premium for December and January must have been deducted from those benefits. And the premium must not be raised by the income-related adjustment. When all three hold, the Part B premium cannot rise by more than the amount that would push the December benefit, paid in January, below the November benefit after the premium. In practice this protects people with small benefits, because only for them can a COLA be smaller than the premium increase. On this page's alternate example, a $600.00 benefit rises 2.8% to $616.80, a $16.80 COLA. With the full $202.90 premium, the deposit would fall from $415 to $413. Hold harmless stops that, holding the premium to $201.80 so the deposit stays at $415. The protected person gets no increase in the deposit, but no cut either. With a $2,000.00 benefit the rule never comes into play, because the $56.00 COLA covers the $17.90 rise several times over. Several groups are not protected and pay the full increase. People who pay IRMAA are excluded by the statute. People whose premium is not deducted from Social Security are excluded, which includes those who pay Medicare directly and people with Medicaid whose premium is paid by their state. People who were not already receiving benefits with the premium deducted at the end of the prior year, such as new enrollees, do not meet the November and December test. On the page, the same $600.00 benefit with the first-tier IRMAA surcharge gives a deposit that falls from $333 to $332, $12 over the year, because nothing caps the premium.
Rounding, your notice, and an early look at 2027
The numbers on an SSA notice rarely match a simple percentage, and rounding is the main reason. SSA's Program Operations Manual, section RS 00601.020, sets two rules for benefits computed since mid-1982. A monthly benefit that is not a multiple of ten cents is rounded down to the next lower dime. The final monthly benefit, after deductions such as the Part B premium, is then rounded down to the next lower whole dollar. On the example, $2,000.00 × 1.028 is exactly $2,056.00, but $2,056.00 less the $202.90 premium is $1,853.10, which is paid as $1,853. That is why a deposit can rise by a dollar more or less than the COLA minus the premium increase would suggest. There is a second reason a notice can differ slightly from this page. SSA applies the COLA to the primary insurance amount behind your benefit and then recomputes the benefit, with its reductions for early claiming or its credits for delay, rather than multiplying the benefit itself. The difference is usually a dime or a dollar. Your notice, or your online Social Security account, is the authority. Looking ahead, the 2027 COLA will be set the same way, from the July to September 2026 average of CPI-W against the 2025 average of 317.265. Two of the three months are already published. BLS reported CPI-W of 327.104 for July 2026 and 328.481 for August 2026. Their average is 3.3% above the 2025 figure, and if September comes in at August's level the COLA would round to 3.4%. Treat both as estimates: September's figure is released in October 2026, and SSA announces the COLA shortly after. The 2027 Part B premium is set separately by CMS, which announced the 2026 premium on 14 November 2025, so the net effect on a deposit will not be known until both are published.
Frequently asked questions
How much is the 2026 Social Security COLA?
2.8%, starting with benefits for December 2025 that were paid in January 2026. SSA sets it from the Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W): the July to September average rose from 308.729 in 2024 to 317.265 in 2025, 2.8% rounded to the nearest tenth. On this page's example a $2,000.00 benefit becomes $2,056.00, $56.00 a month more.
How much of my COLA does the Medicare Part B premium take?
CMS set the 2026 standard Part B premium at $202.90 a month, up $17.90 from $185.00 in 2025 (fact sheet of 14 November 2025). On a $2,000.00 benefit the COLA adds $56.00, so the premium rise takes 32.0% of it. The deposit goes from $1,815 to $1,853, up $38 a month and $456 over the year. The smaller the benefit, the bigger the share the premium takes.
What is the hold-harmless provision?
A rule in section 1839(f) of the Social Security Act that stops a Part B premium increase from shrinking your Social Security deposit. It applies if you received benefits for November and December of the prior year, your premium for December and January was deducted from them, and you pay no income-related surcharge. On a $600.00 benefit the COLA makes $616.80; with the full $202.90 premium the deposit would fall from $415 to $413, so the premium is held to $201.80 and the deposit stays at $415. At a 2.8% COLA and a $17.90 rise, the rule only binds below a benefit of about $639.
Why doesn't my deposit rise by exactly 2.8%?
Because of SSA's rounding and the premium. Under SSA's Program Operations Manual (RS 00601.020), a benefit that is not a multiple of 10 cents is rounded down to the dime, and the payment after the Medicare premium is rounded down to the whole dollar. $2,056.00 less $202.90 is $1,853.10, which is paid as $1,853. SSA also applies the COLA to the primary insurance amount behind your benefit, so your notice can differ from this page by a dime or a dollar.
Who does not get hold-harmless protection?
People who pay an income-related surcharge (IRMAA) on Part B, people whose premium is not deducted from their Social Security check, including those whose premium Medicaid or a state pays, and people who were not already receiving benefits with Part B deducted at the end of 2025, such as new enrollees. They pay the full increase. On a $600.00 benefit with the first-tier $81.20 surcharge, for example, the deposit falls from $333 to $332, $12 over the year, because the $17.90 premium rise is more than the $16.80 COLA.
What will the 2027 COLA be?
Nobody knows until SSA announces it in October 2026, after September's CPI-W is released. An early estimate is possible: July and August 2026 CPI-W came in at 327.104 and 328.481, an average 3.3% above the July to September 2025 average of 317.265. If September lands at August's level, the COLA would be 3.4%. Treat both figures as estimates.
If I pay Medicare directly, what does the COLA leave me?
Your whole COLA arrives in the deposit, but the premium rise comes out of your budget instead, and hold harmless does not protect you. On a $2,000.00 benefit the deposit rises from $2,000 to $2,056, and after paying $17.90 more for Part B you are $38.10 a month better off, $457.20 over the year.