Insulin Cap and IRA Impact: What the $35 Limit Means for Diabetes Costs in 2026

How the Inflation Reduction Act Changed Insulin Pricing

The IRA's insulin provision, codified under Section 11407 of the Inflation Reduction Act of 2022, imposed a mandatory $35 monthly copay ceiling on all Part D and Part B insulin products for Medicare enrollees beginning January 1, 2023 [1]. Before this law, roughly 3.3 million Medicare Part D beneficiaries used insulin, and the median out-of-pocket cost ranged from $54 to $70 per month depending on plan design, according to analysis from the Kaiser Family Foundation [2].

The cap applies per insulin product per 30-day supply. A Medicare patient prescribed both a long-acting basal insulin and a rapid-acting mealtime insulin pays a maximum of $70 combined per month ($35 each). Deductibles no longer apply to insulin under Part D, a detail that saved beneficiaries an estimated $734 million in the first calendar year according to Congressional Budget Office projections [3].

The law did not set a ceiling for commercially insured or uninsured patients. That gap prompted separate action from manufacturers and from state legislatures. As of May 2026, 25 states and the District of Columbia have passed their own insulin price cap statutes covering state-regulated commercial plans [4].

Manufacturer Price Cuts and Voluntary Caps

Market pressure from the IRA triggered voluntary pricing changes that expanded the $35 ceiling beyond Medicare. Eli Lilly announced in March 2023 that it would cap out-of-pocket insulin costs at $35 for all patients with commercial insurance and cut the list price of Humalog (insulin lispro) by 70%, from $274.70 to $82.41 per vial, with a further reduction to $66.40 effective January 2024 [5]. Lilly also introduced Insulin Lispro, an authorized generic, at $25 per vial.

Novo Nordisk followed in January 2024 by capping patient costs at $35 per month for all of its insulin products (Novolog, Levemir, Fiasp, NovoLog Mix 70/30) regardless of insurance status and reducing the list price of several older insulins by up to 75% [6]. Sanofi cut the list price of Lantus (insulin glargine) by 78% to $78 per vial, effective January 2024, and committed to a $35 copay cap for all commercially insured Lantus users [7].

These voluntary commitments matter because the IRA alone left roughly 27.6 million Americans with diabetes who are not on Medicare without a federal price ceiling [8]. The manufacturer caps partially close that gap for insured patients but still rely on pharmacy benefit manager (PBM) pass-through economics.

The Cost of Insulin in 2026: Where Prices Stand Now

Average out-of-pocket insulin costs have dropped substantially. A Health Affairs study published in April 2025 found that mean monthly out-of-pocket spending among Medicare Part D insulin users fell from $57.30 in 2022 to $24.80 in 2024, a 56.7% reduction [9]. The remaining cost below $35 reflects patients using only one insulin or switching to lower-tier products.

For commercially insured patients, the IQVIA Institute reported that average insulin net prices (after rebates) declined 41% between 2022 and 2025, with the sharpest drops among rapid-acting analogs [10]. Here is what common insulin formulations cost at list price as of Q1 2026:

• Humalog (insulin lispro) 100 units/mL vial: $66.40 (Lilly list price)
• Insulin lispro authorized generic vial: $25.00
• NovoLog (insulin aspart) FlexPen 5-pack: $119.60 (Novo Nordisk)
• Lantus (insulin glargine) SoloStar 5-pack: $92.00 (Sanofi)
• Novolin R (OTC regular insulin) vial: $24.88 (ReliOn at Walmart)
• Basaglar (insulin glargine biosimilar) KwikPen 5-pack: $98.00 (Lilly)

List price is not the same as what you pay. The $35 copay cap (federal for Medicare, voluntary for many commercial plans) means most insured patients pay significantly less than list. Uninsured patients can access manufacturer programs. Lilly's Insulin Value Program provides any Lilly insulin for $35 per month without insurance verification [5]. Novo Nordisk's Patient Assistance Program covers eligible uninsured patients at no cost, requiring household income below 400% of the federal poverty level [6].

What the $35 Cap Does Not Cover

The $35 ceiling is specific to insulin drug products. It does not apply to other diabetes medications, devices, or supplies. This creates meaningful cost gaps for patients who need comprehensive glycemic management.

Continuous glucose monitors (CGMs) are covered under Medicare Part B as durable medical equipment for beneficiaries using insulin, but they carry a separate 20% coinsurance obligation. The average retail cost of a Dexcom G7 system runs approximately $300-$400 per month without insurance, while the FreeStyle Libre 3 costs roughly $150-$200 per month at retail [11]. The IRA included provisions to expand CGM access, and CMS finalized coverage for all insulin-treated Medicare beneficiaries (not just those on intensive regimens) beginning in 2024 [12].

Insulin pump supplies, including infusion sets and reservoirs, fall under Part B or Part D depending on the pump type. The IRA Part D redesign capped total out-of-pocket spending at $2,000 annually starting in 2025, which provides indirect relief for patients with high cumulative costs across insulin, supplies, and other prescriptions [3].

GLP-1 receptor agonists prescribed for type 2 diabetes (semaglutide, tirzepatide, dulaglutide) are not insulin products and are not covered by the $35 cap. These can cost $900-$1,200 per month at list price. However, the IRA's broader Part D redesign provisions, including the elimination of the coverage gap ("donut hole") and the $2,000 annual out-of-pocket maximum, do reduce the total financial exposure for patients on multiple diabetes medications [13].

Insulin needles and syringes may or may not be covered depending on plan formulary design. A 2023 analysis in Diabetes Care found that supply costs add an average of $12-$18 per month to insulin therapy [14]. Some states include supplies in their insulin copay cap laws, but the federal IRA statute does not.

Impact on Insulin Rationing and Health Outcomes

Insulin cost barriers have direct clinical consequences. A 2019 CDC analysis estimated that 1.3 million U.S. adults with diabetes rationed insulin due to cost, associated with a 2.3-fold increase in emergency department visits for hyperglycemic crises [15]. A Yale study published in Annals of Internal Medicine found that insulin underuse due to cost was associated with a 0.5% higher mean HbA1c and a 1.85 times higher odds of diabetic ketoacidosis hospitalization over 12 months [16].

Early evidence suggests the IRA cap is reducing rationing behavior. NORC at the University of Chicago surveyed Medicare beneficiaries in late 2024 and found self-reported insulin rationing fell from 17.4% to 8.9% in the first 18 months after the $35 cap took effect [17]. A separate analysis published in JAMA Internal Medicine showed that monthly insulin fills among Part D beneficiaries increased 5.8% in the first year post-cap, consistent with improved adherence rather than new prescribing [18].

The Endocrine Society's 2024 position statement noted that while the $35 cap was "a meaningful step toward insulin affordability," it called for extending the federal cap to all payer types and for addressing non-insulin cost barriers that continue to drive diabetes management gaps [19].

"The $35 cap removed a major obstacle, but patients still face costs for glucose monitoring, syringes, and comorbidity medications that can exceed $200 per month in aggregate," said Dr. Robert Gabbay, Chief Scientific and Medical Officer of the American Diabetes Association, in a 2024 ADA policy statement [8].

GoodRx, Discount Cards, and Generic Insulin Options

For patients without insurance or with high-deductible plans, discount programs remain an important backstop alongside the manufacturer caps. GoodRx reports typical discount prices for a 10 mL vial of insulin lispro (generic Humalog) between $30 and $55 at major chain pharmacies, depending on location [20]. Generic insulin glargine (Semglee, available as both a branded biosimilar and interchangeable biosimilar) can be found for $45-$75 per 5-pen box through discount platforms.

Over-the-counter (OTC) insulin remains available without a prescription at Walmart under the ReliOn brand. ReliOn Novolin R (regular), Novolin N (NPH), and Novolin 70/30 are priced at approximately $25 per vial. These older human insulin formulations have slower onset and less predictable pharmacokinetics compared to analog insulins and carry a higher risk of hypoglycemia, according to the American Diabetes Association's Standards of Care [21]. They are not interchangeable with rapid-acting or long-acting analogs without physician-guided dose adjustment.

Mark Cuban's Cost Plus Drugs offers insulin lispro 100 units/mL vials at a transparent markup model, with prices in the $30-$40 range. The 340B Drug Pricing Program also provides substantially discounted insulin to qualifying federally qualified health centers and safety-net hospitals [22].

How the Part D Redesign Amplifies Insulin Savings

The IRA restructured Medicare Part D in phases. The $35 insulin cap took effect in 2023. The elimination of the 5% catastrophic-phase coinsurance began January 2024. The $2,000 annual out-of-pocket maximum took effect January 2025 [3]. For a patient using two insulin products plus a CGM and oral diabetes medications, the $2,000 cap provides a hard ceiling that did not previously exist.

Before the IRA, Medicare Part D had no out-of-pocket maximum. Patients in the catastrophic phase still owed 5% of drug costs. For a patient with annual insulin and diabetes supply costs exceeding $10,000, that 5% coinsurance alone could total $500 or more. The combination of the $35 insulin cap and the $2,000 total cap means a Medicare beneficiary's maximum annual insulin spend is now $420 (12 months x $35) per product, and their total Part D drug spending across all medications cannot exceed $2,000 [13].

CMS data indicates that approximately 1.5 million Medicare enrollees would have exceeded the $2,000 threshold under the old cost-sharing structure, collectively saving an estimated $7.4 billion annually [23].

What to Expect: Pending Legislation and Pricing Trends

Several bills introduced in the 119th Congress would extend the $35 federal cap to commercial insurance and the uninsured, though none have reached a floor vote as of May 2026. The Insulin Price Reduction Act (S. 225) and the INSULIN Act (H.R. 648) both propose applying the $35 ceiling to all payer types at the federal level [4].

Biosimilar competition continues to expand the insulin market. The FDA has approved six insulin biosimilars as of May 2026, including interchangeable designations for Semglee (insulin glargine) and Rezvoglar (insulin glargine) [24]. Greater biosimilar uptake is expected to push net prices lower through formulary competition, independent of legislative caps.

The IRA also introduced inflation-based rebate penalties for Part D drugs whose list prices rise faster than CPI-U beginning in 2023. For insulin manufacturers, this means raising list prices above the rate of general inflation triggers mandatory rebates to Medicare, creating a structural disincentive against future price increases [13].

For patients managing diabetes costs today: verify your specific plan's insulin formulary tier, check whether your insurer has adopted the $35 voluntary cap, and contact the manufacturer's patient assistance program directly if you are uninsured. The NeedyMeds database (needymeds.org) and the ADA's Insulin Help page (insulinhelp.org) maintain updated directories of every available program.