The ACA’s cost-sharing subsidies

Cost-sharing subsidies reduce out-of-pocket spending on Silver plans. Despite lack of federal funding, these benefits remain available to eligible enrollees

Author: Louise Norris | Date Posted: January 15, 2024

ACA cost-sharing subsidies

Key takeaways


The ACA’s premium tax credits have been discussed at length in the media. More than nine out of ten people who had effectuated coverage through the exchanges as of early 2023 qualified for premium subsidies. 1

But there’s another ACA-created health insurance subsidy, known as cost-sharing reductions (CSR, also called cost-sharing subsidies), that 48% of exchange enrollees were receiving as of early 2023. 1 While premium subsidies help pay the cost of the health insurance itself, CSR benefits are available to reduce the out-of-pocket exposure for eligible enrollees.

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As of early 2023, more than 7.5 million exchange enrollees receiving cost-sharing reductions. 1 That was up from about 5.4 million in early 2021, 2 with the increase due in large part to the American Rescue Plan, which has made plans with CSR benefits more affordable (see below for more about the ARP).

Ever since the exchanges went live in the fall of 2013, cost-sharing subsidies have been much less well-understood than premium subsidies. Many people don’t know they exist, even though the federal government spent $7 billion on them in 2017 alone (this was the last year that the federal government funded the cost of CSR, which we’ll also discuss in a moment). This is partly because they don’t show up among the available plans for people who aren’t eligible for them, and also because people who enroll in CSR plans don’t always realize that the plan they’re getting has been enhanced with CSR benefits.

Until late 2017, the benefit subsidization was directly provided by the federal government; since then, the cost of CSR has been added to premiums in most states. This drives up the cost of coverage and thus results in larger premium subsidies, which continue to be directly provided by the federal government. So in a roundabout way, the federal government is still subsidizing a significant portion of the cost of CSR.

Unlike prior years, CSRs were in the media non-stop in 2017, due to President Trump’s ongoing threats to cut off funding, which he ultimately did in October 2017. But confusion about how CSR benefits work—and how they’re still available without federal funding—has remained. So let’s take a look at what these subsidies are, and how they work. (Note that this article is about the ACA’s cost-sharing reductions. But some states have created their own supplemental cost-sharing reductions, which are available in addition to the federal benefits.)

What does health insurance cost-sharing mean?

Cost-sharing refers to the portion of a medical claim that the insured must pay, usually in the form of a deductible, coinsurance, or copay (it does not include premiums, balance billing, or expenses that are not covered by the insured’s policy). Plans sold in the Marketplace/exchange are designated as Platinum, Gold, Silver, Bronze, or catastrophic, depending on their actuarial value, or AV (a measure of the percentage of costs that the plan covers for a standard population). And there are caps on the maximum out-of-pocket costs that any of the plans can impose.

Cost-sharing reduction in a nutshell…

The cost-sharing subsidies are designed to reduce the portion of a claim that an insured will have to pay, and like the premium subsidies, eligibility is based on household income (ACA-specific MAGI). Although premium subsidies can be applied to any of the “metal” plans within the exchange, cost-sharing subsidies are only available on Silver plans.

Although we’ll go into detail in this article in terms of how the cost-sharing subsidies work, all you really need to know is that if your MAGI is no more than 250% of the federal poverty level, and especially if it’s not more than 200% of the poverty level, you need to pay particular attention to the silver plans in the exchange—any cost-sharing subsidies for which you’re eligible will be automatically built into the silver plans.

For enrollments with 2024 effective dates, 250% of the poverty level is $36,450 for a single person and $75,000 for a family of four (note that the prior year’s poverty level numbers are used, and that the limits are higher in Alaska and Hawaii).

Although CSR benefits extend to people with MAGI up to 250% of the poverty level, they’re strongest for people with income that doesn’t exceed 200% of the poverty level (for 2024 coverage, that amounts to $29,160 for a single individual, and $60,000 for a family of four, in the continental U.S.).

People with MAGI between 200 and 250% of the poverty level are eligible for CSR benefits on silver plans, but they may find that the relatively modest benefits aren’t worth the added cost of purchasing a silver plan instead of a lower-cost bronze plan. Or they may find that a gold plan is available for roughly the same price as a silver plan, with better benefits, due to the way the cost of CSR is being added to silver plan premiums in most areas. However, some states offer their own additional cost-sharing reductions that can be beneficial to these enrollees.

Who is eligible for cost-sharing reductions?

The Affordable Care Act introduced cost-sharing reductions (CSR) as a means of keeping health care costs (as opposed to just insurance premiums) affordable for people with modest incomes. The American Rescue Plan (ARP) made significant changes to how premium subsidy eligibility and amounts are determined, but didn’t change the rules regarding cost-sharing reductions.

CSR benefits are available to enrollees with MAGI between 100% and 250% of the federal poverty level (in states that have expanded Medicaid, which includes the majority of the country, enrollees are eligible for Medicaid with incomes up to 138% of the poverty level; cost-sharing subsidy eligibility starts above that point).

For coverage effective in 2024, 250% of FPL is equal to $36,450 for a single person, and $75,000 for a family of four. This chart shows the MAGI amounts that apply for other household sizes, and those numbers will apply for any plans with a 2024 effective date. For premium subsidies and CSR eligibility, the prior year’s poverty level numbers are always used, so 2023 poverty level numbers are used to calculate eligibility for financial assistance on 2024 health plans.

Until October 2017, HHS reimbursed insurance carriers directly to cover the cost of cost-sharing subsidies, and unlike the premium subsidies, cost-sharing subsidies do not have to be reconciled when insureds file their taxes. Cost-sharing subsidies are automatically incorporated into Silver plans when eligible enrollees shop for plans through the exchanges. Although the federal government is no longer reimbursing insurers for the cost of providing cost-sharing reductions (including the special cost-sharing reductions that are available for American Indians and Alaska Natives), the availability of the benefits themselves has not changed. Anyone who is eligible for cost-sharing subsidies can still receive them.

How do cost-sharing reductions affect out-of-pocket maximums?

The first aspect of CSR reduces the maximum out-of-pocket exposure on a silver plan for households with incomes between 100 and 250% of the federal poverty level. This subsidy was originally intended for enrollees with incomes up to 400% of poverty level, but HHS later ruled that the subsidy would end at 250% of the poverty level.

For 2024 coverage, the unsubsidized out-of-pocket maximum for an individual is $9,450, and the limit is $18,900 for a family 3 (these limits will decrease to $9,200 and $18,400, respectively, in 2025). 4

But for enrollees who are CSR-eligible and who pick a silver plan, the maximum out-of-pocket is lower. (See Table 1 in this CMS guidance for the 2024 plan year). These plans only appear on the exchange websites for applicants who qualify for them. For those who aren’t eligible for CSR, the silver plans will have their regular out-of-pocket maximum (ie, up to $9,450 for an individual in 2024):

How do cost-sharing reductions affect actuarial value?

The second aspect of cost-sharing subsidies works by increasing the actuarial value (AV) of the plan. Under the ACA (aka Obamacare), all Silver plans have an actuarial value of roughly 70%. The plan designs vary and there are different ways that the AV target can be achieved. But the basic idea is that a Silver plan will cover roughly 70% of medical bills across a standard population. But this varies considerably when we look at it on a per-enrollee basis (ie, for insureds with low claims, the carrier will end up paying less than 70% of their costs, but for enrollees with very high claims, the insurer will end up paying much more than 70% of their total costs).

For eligible enrollees, this aspect of cost-sharing subsidies increases the AV of a Silver plan to between 73% and 94%. AV is increased based on income. For enrollees with household MAGI between:

In addition, American Indians and Alaska Natives with MAGI under 300% of the poverty level are eligible for plans with zero cost-sharing.

Cutting through the confusion

There’s plenty of confusion around the cost-sharing subsidies, a lot of which stems from misconceptions about how out-of-pocket maximums and actuarial value differ. To understand the cost-sharing subsidies, it helps to think of the reduction in out-of-pocket maximum as a safety net that’s there to catch you in a worst-case scenario. If you have a claim that’s large enough to cause you to reach your out-of-pocket maximum, the cost-sharing subsidies will make the burden easier to bear by reducing the maximum amount that you would have to pay.

A lot of people don’t meet their out-of-pocket maximum most years. But they may have several smaller expenses throughout the year, and the costs can still be difficult to manage. That’s where the AV-increasing aspect of cost-sharing subsidies comes in. It reduces the insured’s portion of expenses right from the start, even if the out-of-pocket maximum is not reached.

So an insured with a household MAGI of 140% of FPL who picks a Silver plan would end up with a policy that covers an average of 94% of costs (across all enrollees), instead of a policy that covers 70% of costs. For this person, the out-of-pocket maximum in 2024 is also reduced by 67% (from the regular maximum out-of-pocket of $9,450 to the adjusted maximum out-of-pocket of $3,150, keeping in mind that plans can offer out-of-pocket limits that are lower than those amounts). That aspect of the cost-sharing subsidies would be beneficial if and when the claims exceeded $3,150.

But the increased AV is beneficial even in the case of less expensive claims, as it keeps deductibles and copays lower than they would otherwise be.

Although eligibility for subsidies is based on other factors in addition to income, households with MAGI up to 250% of FPL are virtually always eligible for premium subsidies as well as both cost-sharing subsidies. This goes a long way toward making health insurance and health care more affordable and accessible.

What happened when the Trump administration cut off funding for CSR?

There was legal uncertainty surrounding cost-sharing subsidies starting in 2014, but it took on new importance under the Trump administration. In 2014, House Republicans (including Tom Price, who was then a U.S. Representative from Georgia, but left his seat to briefly lead HHS under the Trump Administration, before resigning in September 2017) brought a lawsuit against the Obama administration, alleging that billions of dollars in funding for the cost-sharing subsidies had never been allocated by Congress, and was thus being distributed illegally by HHS (Nicholas Bagley, University of Michigan Law School professor, explained that the lawsuit was not without merit).

In 2016, a district court judge sided with House Republicans, ruling that the cost-sharing subsidies were illegal and could not continue. The ruling was stayed, however, to allow the Obama administration to appeal, which they did. Throughout that process, cost-sharing reduction money continued to flow from HHS to health insurers across the country.

Once Trump won the presidency, the issue took on a new urgency, given the GOP’s efforts to eliminate the ACA. For the first several months of Trump’s presidency, the lawsuit over cost-sharing subsidies was pended. But in October 2017, the Trump administration announced that CSR funding would end immediately. That meant that insurers would not receive reimbursement from the federal government for CSR benefits provided in the final quarter of 2017 and beyond.

Trump’s announcement came after insurers had finalized their rates for 2018. But most insurers had already anticipated the elimination of CSR funding, and had priced their plans for 2018 accordingly, adding the cost of CSR to premiums. In most states where the assumption had been that CSR funding would continue, insurers scrambled to revise their 2018 premiums in October 2017 (just days before the start of open enrollment), adding the cost of CSR to the rates.

Insurers in most states ultimately ended up adding the cost of CSR to their silver plan premiums for 2018. The Kaiser Family Foundation had previously estimated that without cost-sharing reduction funding, rates on silver plans would increase by an additional 19% in 2018, on top of the rate increases that would have applied if CSR funding had continued.

With few exceptions, insurers generally opted to continue to participate in the Marketplaces (exchanges), despite the elimination of CSR funding. Some insurers had opted earlier in 2017 to exit the exchanges for 2018, and the uncertainty over CSR funding was generally cited as a reason for the exits. However, the official elimination of CSR funding did not result in an additional exodus of insurers from the exchanges.

And because the cost of CSR has mostly been added to silver plan rates since 2018, premium subsidies are much larger than they were before 2018, and are disproportionately large compared with the cost of non-silver plans. For enrollees who received premium subsidies in 2021, the average subsidy amount (before the ARP boosted subsidies significantly) was $486/month; in 2017, it was $373/month. Not all of that increase was due to the handling of CSR costs, but a significant portion of it was.

(Subsidies got even larger in 2022, due to the American Rescue Plan, which took effect mid-way through 2021; the average subsidy amount as of early 2022 was $508/month, and as of early 2023, the average subsidy amount was $527/month. 1 )

The larger premium subsidies are beneficial to all enrollees who get premium subsidies—not just those who get CSR benefits. So in a roundabout way, the federal government is still funding CSR. They’re just doing so via larger premium subsidies, instead of directly reimbursing insurers.

Do all marketplace insurers add the cost of CSR to silver plan premiums?

There is some state-to-state variation in terms of how this is handled, but the answer is mostly yes. “Silver loading” (adding the cost of CSR to silver plan premiums) is by far the dominant strategy being used by insurers across the country.

In August 2018, HHS issued guidance on the issue, actively encouraging states to promote on-exchange-only silver loading. Quite a few states took that approach for 2018, but even more did so for 2019, including North Dakota, Delaware, Vermont, and Colorado, where insurers weren’t allowed to silver load at all for 2018. West Virginia joined them for 2022, leaving only Indiana and Mississippi where a broad load approach is still required as of 2024. (In DC, the cost of CSR is still not being added at all, but very few enrollees in DC receive CSR benefits, so the cost is negligible.)

Texas and New Mexico have recently led the way in pricing reforms by requiring marketplace insurers to set prices for silver plans based on the fact that most silver plans actually have actuarial values (AV) of 87% or 94% — as opposed to the standard silver plan AV of 70% — because most people who enroll in silver plans are eligible for strong CSR. This has resulted in larger subsidies, and thus a decrease in the number of people who select bronze plans and an increase in the number of people who are eligible for zero-premium gold plans (since the silver plans are priced higher than gold plans, given their higher realistic actuarial value; that means subsidies based on the cost of the second-lowest-cost silver plan can often cover the full price of a gold plan).

In most states, the cost of CSR is added only to on-exchange Silver plans. Separate off-exchange-only silver plans are available in many areas, without the cost of CSR added to their premiums. This provides an alternative for people who want to buy a silver plan but who don’t qualify for premium subsidies, since they have to pay full-price for their plan and the option without the cost of CSR added to the premiums is more affordable. (But note that far fewer people are ineligible for premium subsidies now, thanks to the ARP’s elimination of the “subsidy cliff.” This will continue to be the case through at least 2025) In addition, since the cost of CSR is then added to a smaller total number of plans (since it’s not added to the plans that are only sold outside the exchange), the additional amount that’s added to each plan is larger, resulting in even bigger premium subsidies for everyone who qualifies for premium subsidies.

Enrollees can still get CSR benefits, and premium subsidies are much larger than they would have been if CSR funding had continued

CSR benefits are still fully available to eligible enrollees who select Silver plans, and cost-sharing reduction benefits are available to American Indians and Alaska Natives enrollees. In short, nothing has changed about eligibility for cost-sharing subsidies. But rather than the federal government directly reimbursing insurers for the cost of CSR, the cost is now almost universally being added to silver plan premiums.

Since premium subsidy amounts are based on the cost of silver plans (specifically, the benchmark silver plan in each area), premium subsidies are much larger than they would otherwise have been (as noted above, average subsidy amounts were about 30% larger in 2021 than they were in 2017; a significant portion of the increase was due to silver loading that went into effect in most states in 2018 or 2019). Even before the American Rescue Plan made subsidies much more robust, enrollees with modest incomes in many parts of the country were eligible for free bronze plans — or even free gold plans, in some cases — after their premium subsidies are applied (with the American Rescue Plan in place, even more enrollees are eligible for free bronze, gold, or silver plans).

According to a Kaiser Family Foundation analysis, there were already 4.5 million uninsured Americans who could get FREE bronze plans for 2021, after the premium subsidies were applied. That was about 16% of the total uninsured population in the US. And again, the American Rescue Plan significantly increased the number of people eligible for a premium-free plan, including premium-free Silver plans. After the ARP was implemented, an updated Kaiser Family Foundation analysis found that at least 6 million uninsured Americans were eligible for premium-free coverage in the marketplace.

Although deductibles are high on bronze plans, all plans include free preventive care, and coverage for non-preventive care with a high deductible is certainly better than no coverage at all. Keep in mind that insurance companies tend to have negotiated rates that are far below the amounts that doctors and hospitals bill. If an in-network provider bills $2,000 and your insurer’s approved amount is $750, you only have to pay $750, even if you have a high deductible and are thus responsible for paying the full bill. This is an often-overlooked benefit of having health insurance, even if the deductible seems impossibly high.

It’s important to understand that many of those 6 million people might be better served by picking a Silver plan if they’re eligible for cost-sharing reductions, and the American Rescue Plan makes it much more realistic for them to do so. This is particularly true if their MAGI doesn’t exceed 200% of the poverty level ($29,160 for a single person in 2023), since the most robust CSR benefits are available for people with income up to 200% of the poverty level. Yes, the Silver plan will have higher premiums, but it will also provide more robust coverage than a free Bronze plan. But if you’re uninsured and simply can’t afford the premium for a Silver plan, enrolling in a free Bronze plan is far preferable to remaining uninsured.

What do I need to know about CSR pricing if I don't qualify for premium subsidies?

People who don’t get premium subsidies have to pay the higher premiums that include the cost of CSR, but in most states, this only applies if they select a silver plan (but note that most people do qualify for premium subsidies, especially with the American Rescue Plan and Inflation Reduction Act in place). And in states where the cost of CSR is added only to on-exchange plans, lower-cost off-exchange silver plans are available to people in this situation. California led the way on this approach, but numerous other states also adopted it.

It’s worth noting here that although adding the cost of CSR only to on-exchange silver plans does serve to protect consumers, it may have also placed some people with variable income in a tricky situation. Enrollees who want a silver plan and aren’t eligible for premium subsidies will often find that silver plans are cheaper off-exchange, due to the cost of CSR being added to the on-exchange silver plans. But before 2020, if that person signed up for an off-exchange plan, they couldn’t switch to an on-exchange plan if their income dropped mid-year to a subsidy-eligible level (before 2020, a drop in income was not a qualifying event if you were not already enrolled in a plan through the exchange).

For self-employed people, who have variable income, or who might simply lose their job or have their hours reduced mid-year, this presented a potential conundrum: Should you enroll in the lower-price off-exchange silver plan, knowing that if your income were to drop mid-year, you wouldn’t be able to get premium subsidies? Or should you enroll in the higher-price on-exchange plan, knowing that if your income were to drop during the year, you’d be able to start getting subsidies at that point (or claim them on your tax return)?

There was no easy answer to this, but it’s an issue that HHS addressed for 2020 and future years. Starting in 2020, people with off-exchange coverage (including those who take advantage of lower-cost silver plans outside the exchange) who experience an income change that makes them subsidy-eligible are allowed to switch to an on-exchange plan at that point.

Note that although HealthCare.gov planned to offer this special enrollment period starting in 2020, they made it optional for state-run exchanges—so there’s no guarantee that all of the state-run exchanges offer this special enrollment period. For reference, the details of this special enrollment period are outlined here.

Despite CSR defunding, the federal government is still picking up most of the tab via larger premium subsidies

Enrollment in the exchanges for 2018 ended up being nearly as high as 2017’s enrollment, despite an open enrollment period that was half as long. Although there was considerable consternation in 2017 that the elimination of CSR funding could result in a mass exodus of insurers from the exchanges and a destabilized individual market, that did not come to pass.

For 2019, there was an influx of insurers joining the exchanges in many states, and that trend continued for 2020, for 2021, and for 2022. It continued again for 2023, but there were also some high-profile insurer exits for 2023. For 2024, there was a combination of insurer exits and entries, but more entries than exits overall.

Exchange enrollment and overall average premiums remained very steady after CSR funding was eliminated. Enrollment hit record highs in 2022 and again in 2023, when more than 16 million people signed up for coverage during open enrollment. For 2024, a significant new record high was reached even before the enrollment period ended, with more than 20 million people enrolled by mid-December. 5

Because insurers and state regulators were anticipating the loss of CSR funding (or reacted swiftly after it was officially eliminated), the cost of CSR has been adequately incorporated into the premiums insurers collect. And because it is generally added to silver plan premiums, on which premium subsidies are based, premium subsidies for nearly everyone eligible for them (which is considerably larger than the number of people who get cost-sharing subsidies) are much larger than they would have been if the federal government had continued to fund CSR directly.

The overall result is that the federal government is really still funding CSR, via larger premium subsidies rather than direct reimbursement. And more people end up benefiting, since premium subsidies extend to households earning up to 400% of the poverty level (or even higher, from 2021 through at least 2025), whereas CSR benefits stop at 250% of the poverty level.

There was some talk towards the end of 2017 about reviving the Alexander-Murry bill that would allocate federal funding for CSR, but this would no longer be as helpful as it would have been in mid-2017, as the CSR funding situation has been resolved in a way that ends up being more beneficial for exchange enrollees. In other words, most enrollees are better off with the federal government NOT funding CSR. And in most states, people who aren’t eligible for premium subsidies can generally pick an off-exchange plan or a non-silver plan to avoid paying the added cost to cover CSR; they’re not better off, but they’re also not any worse off.

Louise Norris is an individual health insurance broker who has been writing about health insurance and health reform since 2006. She has written dozens of opinions and educational pieces about the Affordable Care Act for healthinsurance.org.

  1. Effectuated Enrollment: Early 2023 Snapshot and Full Year 2022 Average . Centers for Medicare and Medicaid Services. Published 2023. ⤶⤶⤶⤶
  2. Effectuated Enrollment: Early 2021 Snapshot and Full Year 2020 Average . Centers for Medicare and Medicaid Services. Published 2021. ⤶
  3. Premium Adjustment Percentage, Maximum Annual Limitation on Cost Sharing, Reduced Maximum Annual Limitation on Cost Sharing, and Required Contribution Percentage for the 2024 Benefit Year. Centers for Medicare and Medicaid Services. December 2022. ⤶⤶⤶
  4. Premium Adjustment Percentage, Maximum Annual Limitation on Cost Sharing, Reduced Maximum Annual Limitation on Cost Sharing, and Required Contribution Percentage for the 2025 Benefit Year. Centers for Medicare and Medicaid Services. November 15, 2023. ⤶⤶⤶
  5. Under the Biden-Harris Administration, Over 20 Million Selected Affordable Health Coverage in ACA Marketplace Since Start of Open Enrollment Period, a Record High . Centers for Medicare and Medicaid Services. January 2024. ⤶