When the federal $35 insulin copay cap took effect for Medicare Part D in 2023, policymakers and patient advocates celebrated a rare bipartisan win against rising drug costs. Yet for millions of Americans with private insurance or no coverage at all, the pharmacy counter still tells a different story. A vial of analog insulin can carry a list price above $300, and even with a capped copay, the path to that price runs through deductibles, coinsurance, and formulary rules that vary by plan, employer, and state. For some patients, the monthly cost of staying alive with type 1 or type 2 diabetes still rivals what a family spends on food.

The Copay Cap That Didn't End the Sticker Shock

The Inflation Reduction Act's $35 monthly cap on insulin for Medicare Part D beneficiaries took effect in January 2023. For the roughly 3.3 million Medicare enrollees who use insulin, that cap delivered immediate relief at the pharmacy counter. But Medicare covers only a fraction of the 8.4 million Americans who use insulin. The majority get coverage through employer-sponsored plans, the individual marketplace, Medicaid, or none at all.

For those in commercial plans, the cap often does not apply. The federal limit extends to Medicare and, in some cases, to plans sold on the Affordable Care Act exchanges, but many large employer plans are self-funded, meaning the employer itself bears the insurance risk. Self-funded plans are governed by federal law, not state insurance mandates, and they are not required to cap insulin copays. According to the Kaiser Family Foundation, roughly 60% of covered workers were in self-funded plans as of 2023, and those plans are free to set their own cost-sharing structures.

Even when a plan does cap copays, the cap typically applies only after the patient has met their deductible. A high-deductible health plan with a $3,000 deductible means the first several hundred dollars of insulin costs come entirely out of pocket. For a patient who fills a 30-day supply each month, the deductible phase can stretch for months, and the annual reset means the cycle repeats every January.

The gap between policy promise and real cost shows up in patient surveys and clinical anecdotes. Endocrinologists report seeing patients who skip doses, stretch vials, or switch to older human insulin to save money. A 2021 study in the Annals of Internal Medicine found that one in five insulin users reported rationing their supply, and the practice was more common among those with high-deductible plans.

Why a $35 Cap Can Still Mean $300 at the Pharmacy

The arithmetic of insulin pricing starts with the list price, which is set by manufacturers and has risen steadily for decades. For a typical analog insulin like insulin lispro or insulin glargine, a single vial can list at $300 or more, and a monthly supply often requires two to three vials, depending on the patient's dose. Some patients use pen devices that cost even more per unit.

Insurance plans negotiate rebates with manufacturers through pharmacy benefit managers (PBMs), but those rebates are tied to the list price, not to what the patient pays. A plan might negotiate a net price of $150 per vial after rebates, but the patient's cost-sharing is often calculated on the list price or a negotiated rate that is still far above the net. For a patient in the deductible phase, the full negotiated price, often several hundred dollars, is charged directly.

Even after the deductible is met, coinsurance, a percentage of the drug's cost, can leave a patient with a $60 to $100 copay for a 30-day supply, well above the $35 cap. Only plans that have voluntarily adopted the cap or are required to by state law will charge the lower amount. A patient with a high-deductible plan and no employer-sponsored cap can easily face $300 or more in out-of-pocket costs for a single month of insulin.

For the uninsured, the situation is starker. Without any insurance negotiation, patients are charged the full list price, which for some analog insulins exceeds $500 per month. Some manufacturers offer patient assistance programs that cap out-of-pocket costs for qualifying individuals, but eligibility rules are strict, applications are lengthy, and many patients fall into a coverage gap where they earn too much to qualify but too little to afford the drug.

The Formulary Labyrinth: Step Therapy and Prior Authorization

Even when a patient has insurance that covers insulin, the coverage is not automatic. Many plans require step therapy, a process that forces a patient to try a lower-cost or preferred drug before the plan will cover a more expensive one. For insulin, this often means trying a human insulin like NPH before an analog insulin like glargine, even if the prescribing clinician believes the analog is medically necessary.

Step therapy can delay effective treatment by weeks. A patient who does not respond well to human insulin may need to document that failure, wait for a new prescription, and then appeal if the plan denies coverage. Each step adds time and paperwork, and during that period the patient's glucose control can deteriorate, increasing the risk of short-term complications like hypoglycemia or hyperglycemia, and long-term damage to the eyes, kidneys, and nerves.

Prior authorization is another barrier. Even when a drug is on the formulary, the plan may require the prescriber to submit documentation justifying the use of a specific brand or dosage. The form can take 30 to 60 minutes to complete, and a busy clinician may not have the staff to chase down every approval. Delays of several days are common, and during that time the patient may run out of medication.

Administrative burden falls disproportionately on community clinics and small practices, which often lack dedicated prior authorization teams. A 2022 survey by the American Medical Association found that physicians spend an average of two hours per week on prior authorization tasks, and nearly a third reported that prior authorization led to a serious adverse event for a patient. For insulin, a delay of even a few days can be dangerous.

Hospital Consolidation and the Pharmacy Benefit Middlemen

The drug pricing system that produces these high out-of-pocket costs is shaped in part by consolidation across the healthcare industry. Over the past two decades, hospital systems have merged and acquired physician practices, concentrating market power in a handful of large networks. These systems often have their own specialty pharmacies and negotiate contracts with PBMs that bundle drug purchases with other services.

Pharmacy benefit managers, the middlemen that administer drug benefits for insurers, have also consolidated. Three PBMs, CVS Caremark, Express Scripts, and OptumRx, control more than 80% of the market. They negotiate rebates from manufacturers in exchange for placing drugs on preferred formulary tiers. The rebates are often substantial, but they are calculated as a percentage of the list price, which gives manufacturers an incentive to keep list prices high.

The result is a system where the list price of insulin rises, the rebate grows, and the net price to the health plan may stay flat or even decline. But the patient's cost-sharing, whether a copay or coinsurance, is often based on the list price or a higher negotiated rate, not the net price after rebates. That means patients see the sticker shock of rising list prices without the benefit of the rebates that their premiums are supposedly paying for.

Consolidated hospital systems and PBMs argue that their scale allows them to negotiate lower net prices, and there is evidence that some large systems achieve net prices below what smaller purchasers pay. But those savings rarely translate into lower patient out-of-pocket costs. A 2023 report from the Department of Health and Human Services found that patient cost-sharing for insulin increased by 50% between 2014 and 2019, even as net prices to insurers fell.

State-Level Patchwork: Who's Protected and Who Isn't

In the absence of a broad federal mandate, many states have enacted their own insulin copay caps. As of late 2024, at least 25 states and the District of Columbia had passed laws capping monthly copays for insulin, typically at $25, $35, or $50. These laws apply to plans regulated by the state, which includes individual and small-group plans, and in some states, fully insured large-group plans.

But a significant portion of the insured population is not protected by these laws. Self-funded employer plans, which cover a majority of workers at large companies, are exempt from state insurance regulation under the Employee Retirement Income Security Act (ERISA). That means a state copay cap may not apply to a worker at a large corporation, even if that worker lives in a state with a cap.

Federal employees and members of some unions are also exempt, as their plans are governed by federal law or collective bargaining agreements that may not include a cap. The result is a patchwork where a patient's protection depends on the type of plan they have, the state they live in, and the employer's willingness to adopt a cap voluntarily.

Even in states with caps, the protection only applies to copays, not to the deductible phase. A patient in a high-deductible plan may still pay the full negotiated price until the deductible is met, and the cap does not apply to that amount. Some state laws have attempted to close this gap by requiring that the cap apply regardless of deductible, but enforcement and clarity vary widely.

The Real-World Arithmetic: Insulin vs. Groceries

For a patient with type 1 diabetes, a typical monthly insulin supply can easily cost $500 or more at list price. Even with a capped copay of $35, the deductible phase can add thousands of dollars in upfront costs. The average monthly grocery bill for a single person in the United States, as estimated by the U.S. Department of Agriculture, ranges from roughly $300 to $400, depending on the food plan. For many patients, insulin costs more than food.

Consider a hypothetical patient on a high-deductible plan with a $3,000 deductible. In January, they fill a 30-day supply of insulin that costs $400 at the negotiated rate. They pay the full $400, and continue to do so until they have met the deductible. If the monthly cost is $400, the deductible is met after about seven and a half months. For those first seven months, the patient pays $2,800 out of pocket for insulin alone.

After the deductible, coinsurance kicks in, often 20% to 30% of the negotiated price. At a 25% coinsurance rate, the monthly cost drops to $100, but that is still three times the $35 cap. Only if the plan has adopted the cap does the patient pay $35, and many plans do not.

Patients respond to this arithmetic in ways that clinicians see every day. Some skip doses to make a vial last longer, which can lead to dangerous blood sugar swings. Others switch to older, cheaper human insulin, which requires more careful timing and can be less predictable. A 2023 study in JAMA Internal Medicine found that insulin rationing was associated with a 30% higher risk of diabetic ketoacidosis, a life-threatening complication.

What Would Actually Close the Gap

Extending the $35 cap to all plans, not just Medicare, is the most direct step. A federal mandate would override the state patchwork and cover the majority of Americans with private insurance. Such a policy would need to address the deductible phase, perhaps by requiring that the cap apply from the first fill of the year, not just after the deductible is met.

Banning deductibles for essential chronic medications like insulin is another option. Some plans already offer zero-deductible coverage for preventive drugs, and a similar approach for insulin would eliminate the upfront cost barrier. The trade-off is that premiums might rise slightly, but the reduction in emergency room visits and hospitalizations from uncontrolled diabetes could offset those costs.

Requiring transparent formularies and fast appeals would reduce the administrative burden that delays care. A standardized prior authorization form, with a 24-hour turnaround requirement, would help patients and clinicians alike. Some states have already implemented electronic prior authorization, and expanding those programs nationally would simplify the process.

Negotiating prices directly with manufacturers, as the federal government now does for Medicare, could lower list prices for everyone. The Inflation Reduction Act allowed Medicare to negotiate prices for a small set of drugs, and insulin was included in the first round. Extending that authority to all purchasers, or allowing states to negotiate on behalf of their residents, would reduce the list price that drives patient cost-sharing.

Simplifying patient assistance programs would also help the uninsured and underinsured. A single, national application, with clear income thresholds and automatic renewal, would reduce the burden on patients who are already struggling. Some manufacturers have voluntarily expanded their programs, but eligibility remains restrictive.

Each of these steps has political and logistical hurdles. A federal cap on all plans would face opposition from insurers and PBMs, who argue that cost-sharing is necessary to encourage appropriate use. But insulin is not a discretionary drug; it is a life-sustaining medication. The argument that high copays discourage overuse does not apply to a drug that every patient with type 1 diabetes needs in the same dose every day.

Reasonable people disagree on the best policy mix. Some prefer to strengthen the Affordable Care Act's essential health benefits to include insulin coverage with no deductible. Others advocate for a public option that would set a single, low price. Still others argue that the market should be left alone, and that patient assistance programs are sufficient. The evidence, however, suggests that the current system leaves a meaningful minority of patients with costs that force trade-offs between insulin and other necessities.

The gap between the promise of copay caps and the reality at the pharmacy counter is a reminder that policy wins at the federal level do not automatically reach every patient. For the millions who still pay hundreds of dollars a month for insulin, the question is not whether caps are a good idea, but why they apply to some and not others. Until the coverage gap is closed, the arithmetic of insulin vs. groceries will continue to shape the lives of people with diabetes.

This article is for informational purposes only and does not constitute medical, legal, or financial advice. If you or someone you know is struggling to afford insulin, speak with a healthcare provider or contact a patient assistance program for guidance.