ACA Subsidies in 2027: Why Two Neighbors Can Pay Different Premiums

For 2027, the Affordable Care Act subsidy for Marketplace health insurance, called the premium tax credit, goes back to its original structure unless Congress changes it. The larger credits, known as the enhanced credits, ran from 2021 through 2025 and are gone. The credit is tied to your income compared with the federal poverty line, a yearly figure the government sets by household size, and the old cutoff at 400% of that line is back. For one adult, the cutoff is $63,840 for 2027 coverage, and the limit is higher for larger households. Up to that income you are expected to pay a set share of your income, from 2.15% to 10.22%, toward the benchmark plan, which is the second-cheapest silver plan where you live. The credit pays the rest. One dollar over $63,840 and the credit is zero. The $63,840 is for 2027 plans; the grid below uses 2026 plans, where 400% is $62,600.

That rule is why two neighbors can see very different bills. Below the line, your age and ZIP code change the size of the credit while your cost after the credit usually stays put. Above it, those two facts decide the whole price. Sign-up for 2027 on HealthCare.gov, the federal site Florida uses, starts November 1 and runs to January 15, 2027. Pick a plan by December 15 if you want coverage to start January 1.

How the credit is figured

Three numbers do all the work. The first is the benchmark: the silver plan with the second-lowest price in your area, which HealthCare.gov calls the second lowest cost silver plan, or SLCSP. You do not have to buy it. The second is your expected contribution: a percentage of your yearly household income, set each year by the Internal Revenue Service (IRS). The third is the credit itself, which is the benchmark’s monthly price minus your monthly expected contribution.

Written as a formula, your expected contribution each month is your yearly income times the IRS percentage for that income, divided by 12; the credit is the benchmark’s price minus that amount. You can spend the credit on any plan you pick. If you choose a plan that costs less than the benchmark, such as a bronze plan, the credit still applies in full, up to that plan’s whole premium, and if you choose one that costs more, you pay the difference. Our earlier look at how premiums are set, part of the Healthcare Costs, Decoded series, explains where insurers’ sticker prices come from.

The percentages move every year. For 2027 coverage, IRS Revenue Procedure 2026-26 sets them at 2.15% for incomes under 133% of the poverty line, rising to 10.22% between 300% and 400%. For 2026 coverage, Revenue Procedure 2025-25 set the same range at 2.10% to 9.96%. Each coverage year is measured against the prior year’s federal poverty guideline from the Department of Health and Human Services (HHS), so 2026 plans use the 2025 figure, $15,650 for one person, and 2027 plans use the 2026 figure, $15,960.

A Hillsborough County grid for one adult

To put real prices behind the formula, HeadLines Decoded opened the 2026 qualified health plan county file from the Centers for Medicare and Medicaid Services (CMS), the county-by-county list of individual-market plans for HealthCare.gov states, with data current as of August 4, 2026. We found the benchmark in Hillsborough County, home to Tampa, for one adult at three ages, then ran four incomes through the 2026 IRS table. CMS had not posted 2027 premiums as of October 21, 2026, so every dollar in this grid is a 2026 dollar.

Age	Income (share of 2025 poverty line)	Benchmark premium	Expected contribution	Tax credit	You pay for the benchmark
40	150% ($23,475)	$645	$82	$563	$82
40	250% ($39,125)	$645	$275	$370	$275
40	350% ($54,775)	$645	$455	$190	$455
40	450% ($70,425)	$645	None	$0	$645
50	150% ($23,475)	$902	$82	$820	$82
50	250% ($39,125)	$902	$275	$627	$275
50	350% ($54,775)	$902	$455	$447	$455
50	450% ($70,425)	$902	None	$0	$902
60	150% ($23,475)	$1,370	$82	$1,288	$82
60	250% ($39,125)	$1,370	$275	$1,095	$275
60	350% ($54,775)	$1,370	$455	$915	$455
60	450% ($70,425)	$1,370	None	$0	$1,370

All amounts are monthly and rounded to whole dollars. The grid uses 2026 plans, so the poverty line is $15,650 and 400% is $62,600. Sources: CMS 2026 plan files; IRS Revenue Procedure 2025-25; HHS 2025 poverty guideline. Calculated by HeadLines Decoded, October 21, 2026.

Take the 50-year-old at 250% and work it through. Income is 2.5 times $15,650, or $39,125. The 2026 percentage at exactly 250% is 8.44%, so the expected contribution is $39,125 times 8.44%, or $3,302 a year, which is $275 a month. The benchmark costs $902 a month at that age. The credit is $902 minus $275, or $627, and this buyer’s net cost for that plan is $275.

A note for anyone checking our work. Under a Treasury Department regulation, 26 CFR 1.36B-3, silver plans are ranked only on the part of the premium that pays for the essential health benefits the law requires, so extras such as adult vision coverage are set aside first. In Hillsborough the benchmark is a Florida Blue myBlue Silver plan with adult vision, and CMS’s plan attributes file counts 99.41% of its listed price as essential benefits.

Look at any one income and the net cost is identical for all three ages, $275 a month at 250% for example, because the credit grows to absorb the higher premiums insurers charge older adults.

Income just over 400% of poverty

The jump is sharpest at the line itself. At exactly 400% of the 2025 guideline, or $62,600, a 60-year-old in Hillsborough owes 9.96% of income toward the benchmark, which comes to $520 a month. With one more dollar of income the same plan costs $1,370 a month. That is $850 more each month, or $10,200 over a year. At 450%, the full benchmark takes 23% of that person’s $70,425 income.

A 40-year-old crossing the same line goes from $520 to $645, a jump of $125 a month. The jump exists at every age and is steeper at 60, because that person’s benchmark lists at more than twice the 40-year-old’s price.

The American Rescue Plan Act of 2021 dropped the 400% limit and rewrote the table, and the Inflation Reduction Act of 2022 kept that version through 2025. Under that version the most anyone owed toward the benchmark was 8.5% of income, however much they earned, compared with 9.96% in 2026, and people up to 150% of poverty paid nothing. Section 36B of the tax code limited the table to tax years beginning before January 1, 2026.

Six households, one change each

Each row below changes one thing and holds everything else still, using CMS prices for Hillsborough and the IRS table for each year. The last two columns give the monthly cost of the benchmark plan after the credit, per CMS and IRS figures.

Household	The one thing that moved	Monthly cost before the change	Monthly cost after the change
Age 40 at 250%, from 2025 into 2026	The enhanced credit formula ended	$126	$275
Age 60 at 450%, from 2025 into 2026	The 400% limit came back	$480	$1,370
Age 60 in 2026	Income rose from 350% to 450%	$455	$1,370
Two neighbors at 250% in 2026	Age: one is 40, the other 60	$275	$275
A 60-year-old above the line, 2026	County: Hillsborough, then Orange	$1,370	$1,444
One adult at 250%, moving to 2027	New IRS table and poverty guideline	$275	$288

Take the first row. That 40-year-old’s credit went up, from $363 to $370 a month, because the benchmark price rose 32%, from $489 to $645. The bill still more than doubled, because the share of income the person was expected to pay jumped from 4% to 8.44%. A different plan also became the benchmark, an Ambetter Health silver plan in 2025 and the Florida Blue plan in 2026, so even a household that kept its own plan saw its credit change. CMS’s plan year 2026 fact sheet, published October 30, 2025, projected a lower share covered as well: for a 50-year-old earning twice the poverty level, credits would cover 81% of a benchmark premium for 2026, down from 93% in 2025.

The county row shows what ZIP code does above the line. Orange County’s 2026 benchmark for a 60-year-old, a Health First silver plan, was $74 a month higher than Hillsborough’s.

The plan you pick changes the bill too. Hillsborough’s cheapest 2026 bronze plan for a 60-year-old listed at $1,060 a month, which is $35 less than the $1,095 credit for that age at 250%. Its deductible, the amount you pay for most care before the plan starts sharing costs, was $10,125. Drug coverage also differs from plan to plan, and our next installment covers drug prices (Story coming Mon, Nov 2 at 9:00 AM).

The 2027 numbers already set

Insurers’ 2027 prices have not been published by CMS. When we checked on October 21, the agency had not posted a 2027 version of that county file or a 2027 plans and prices fact sheet. The Peterson-KFF Health System Tracker, reviewing insurers’ proposed 2027 rates in an analysis updated August 3, 2026, found a median proposed increase of 15% across 276 insurers, and it noted that the filings were preliminary.

Your side of the math is already fixed. When the benchmark costs more than your expected contribution, your net cost for it equals that contribution, whatever the premium turns out to be. For 2027, one adult earning 150% of the 2026 guideline ($23,940) will owe $86 a month toward it. At 250% ($39,900) the figure is $288; at 350% ($55,860) it is $476, and at 400% ($63,840) it is $544. Every age in the 2026 Hillsborough grid had a benchmark above those amounts, so for adults aged 40 to 60 in that county these should be the net 2027 prices for the benchmark plan.

Before you enroll, work out your expected 2027 income against the poverty guideline ($15,960 for one person), then find the matching percentage in Revenue Procedure 2026-26. Applied to your yearly income and spread over 12 months, that percentage is what the benchmark costs you each month once the credit is applied.

Where the law stands on October 21

The enhanced credits expired at the end of 2025. On January 8, 2026, the House passed H.R. 1834 by a vote of 230 to 196. The American Hospital Association reported that the bill would extend the enhanced credits for three years and that 17 Republicans joined Democrats in voting for it. Congress.gov shows the bill placed on the Senate calendar on February 10, 2026, and lists no Senate vote since.

CMS reported on March 27, 2026, that 23.1 million people selected or were automatically re-enrolled in a plan for 2026 through HealthCare.gov and the state-run exchanges. That count is taken at sign-up. KFF, counting people actually enrolled, reported on October 6, 2026, that enrollment fell from 21.8 million in 2025 to 19.2 million in 2026, and that what people paid in premiums after credits rose 58% on average.

For HealthCare.gov states, CMS said in a July 27, 2026, statement that open enrollment will begin November 1, 2026, and end January 15, 2027. Fierce Healthcare reported that a federal judge in Maryland vacated a shortened 2027 enrollment period in City of Columbus v. Kennedy and that HHS has appealed to the 4th Circuit, so the dates could still change.

A worksheet for when your income changes

The monthly credit is an advance, based on your own estimate of the year’s income, and the final amount is settled on the federal tax return you file the next spring. Starting with tax year 2026, the One Big Beautiful Bill Act, signed July 4, 2025, removed the cap that once limited how much of an excess advance credit people under 400% had to repay. Any excess now comes back in full.

Say a 40-year-old in Hillsborough signed up expecting to earn $23,475 and received $563 a month in advance credit for 2026. If the year ends at $39,125 and nothing was reported, the credit that person qualified for was $370 a month, or $4,440 for the year. That is $6,756 received against $4,440, and $2,316 owed when taxes are filed. Crossing 400% is harsher. A 60-year-old who started the year at 350% and ended it at 450% would owe back every advance dollar, $10,980 for a full year at $915 a month, because above the line there is no credit for any month.

Keep these numbers on one sheet, and update it the day something changes:

• Your old yearly income estimate and your new one.
• Household size, meaning the people on your federal tax return.
• The benchmark premium. After the year ends, Form 1095-A shows it, and HealthCare.gov’s tax tool can look it up.
• The monthly premium of the plan you chose.
• The advance credit paid to your insurer each month now.
• The date your income changed, and how many months of the year remain.

With those, multiply the new income by the percentage the IRS table gives for that income (for 2027, between 2.15% and 10.22%) and divide by 12. If the new income is above 400%, stop there, because the new credit is zero. Subtract that from the benchmark to get the new monthly credit. The gap between the old credit and the new one, times the months you have already received it, is roughly what you would owe if nothing were reported. HealthCare.gov tells enrollees to update an application as soon as possible when income or household size changes, and the IRS says to report those changes as they happen during the year, since they can cause you to owe tax. You can update online or by calling the Marketplace at 1-800-318-2596.

About this information. This article explains how health care costs and coverage rules work. It is general information. Nothing here is medical, insurance, legal, tax or financial advice. We do not recommend any plan or product. Prices and rules change, so check any figure with the source named here, your plan or a licensed professional before you make a decision. No insurer, hospital, drug company or health plan named in this article paid for it or reviewed it before publication.

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