When John D., a 58-year-old with rheumatoid arthritis in Ohio, finally got a biosimilar approved by his state Medicaid plan in early 2026, he had already spent two years paying out of pocket for a drug that private insurers covered within months of its 2023 FDA approval. His story is not unusual. Across the United States, patients with the same diagnosis can face dramatically different out-of-pocket costs and access timelines depending solely on whether their insurance is a private plan or a state Medicaid program. The gap is baked into the system's design.

The Same Diagnosis, Two Different Cost Ceilings

A patient covered by a large commercial insurer in 2025 might see a monthly specialty drug copay capped at $150, thanks to a plan design that limits out-of-pocket spending. Meanwhile, a Medicaid beneficiary in the same state could be charged over $800 for the identical medication, because many state Medicaid programs do not have an out-of-pocket maximum for prescription drugs. Federal law permits this disparity. The Affordable Care Act set annual out-of-pocket limits for private plans, but it did not extend the same requirement to Medicaid fee-for-service or managed care plans.

Patient advocacy groups have documented at least a dozen cases this year alone where Medicaid enrollees faced bills exceeding $1,000 per month for drugs that private insurers covered with a modest copay. The Kaiser Family Foundation reported in 2025 that roughly 40% of state Medicaid programs had no cap on prescription drug cost-sharing, compared with 100% of private marketplace plans. The result is a two-tier system where financial protection is a function of insurance type, not medical need.

Some states have moved to close the gap. California and New York now cap Medicaid drug copays at $250 per month, but the majority of states have not followed. The federal government could mandate a uniform out-of-pocket maximum for all public plans, but such legislation has stalled in Congress. Without it, the disparity will persist, leaving low-income patients to choose between medication and other necessities.

Prior Authorization as a Wealth Filter

Prior authorization—the process insurers use to approve expensive drugs before they are dispensed—functions differently across payer types. Commercial plans approve roughly 85% of prior authorization requests for specialty drugs, often within 48 hours, using automated algorithms that check formulary status and patient history. In contrast, Medicaid programs deny nearly 40% of such requests, according to a 2025 analysis by the American Medical Association. The denial rate for high-cost biologics is even higher, approaching 50% in some states.

Physicians report spending hours each week on appeals paperwork for Medicaid patients, time that could otherwise go to clinical care. A family medicine doctor in rural Michigan told STAT in early 2026 that she devotes roughly three hours per week to prior authorization appeals for her Medicaid patients, compared with less than one hour for those with private insurance. The delays are also longer: 2 to 4 weeks is common for Medicaid, while private insurers often respond within 1 to 3 days.

The burden falls hardest on patients with chronic conditions who need consistent access to therapy. A missed approval can mean a gap in treatment that leads to disease progression, hospitalizations, and higher overall costs. Some private insurers now use artificial intelligence to predict which drugs will be approved, reducing administrative friction. Medicaid programs, constrained by older IT systems and state budget pressures, rarely have such tools. Prior authorization thus becomes a wealth filter, slowing or blocking care for those who rely on public insurance.

Formulary Design: Who Gets the Newest Drugs

Formulary design—the list of drugs a plan covers—reveals another layer of disparity. Private plans typically include 90% of FDA-approved drugs within six months of market entry, according to a 2025 report from IQVIA. State Medicaid formularies, by contrast, lag by an average of 18 months. The delay stems partly from the negotiation process: state programs must obtain rebates from manufacturers, and those negotiations favor high-volume brand-name drugs over newer therapies. For rare conditions, the lag can be even longer, with some orphan drugs never added to public formularies.

The consequences are tangible. A patient with multiple sclerosis may have access to a new oral disease-modifying therapy through a private plan in 2024 but wait until 2026 for the same drug to appear on a state Medicaid list. During that gap, patients may rely on older, less effective treatments or face high out-of-pocket costs through manufacturer patient assistance programs—but those programs are unevenly available and often require income documentation that can be a barrier for low-income enrollees.

Rebate negotiations also create perverse incentives. Medicaid programs are required by federal law to obtain the best price available, which can lead them to favor drugs with large rebates rather than those with the best clinical evidence. A 2024 study in Health Affairs found that in 12 states, the top five drugs by spending were all brand-name biologics with rebates exceeding 50%, even when cheaper biosimilars were available. Private plans, with more flexibility, often switch to biosimilars quickly to lower costs, a move that also benefits patients through lower copays.

Hospital System Consolidation Worsens the Divide

The consolidation of hospital systems over the past decade has compounded these disparities. In 20 states, a single health system now controls more than 50% of the market, reducing competition and giving insurers less leverage in rate negotiations. Private insurers, however, can still negotiate lower rates with large systems by steering patients to preferred facilities. Medicaid programs have no such leverage; they are required to accept any willing provider, and large systems often refuse to contract with Medicaid at all, or limit the number of beds available to public plan enrollees.

A 2025 study in Health Affairs directly linked hospital consolidation to widening access gaps for Medicaid patients. The study found that after a merger, a system's flagship hospital typically maintained full access for privately insured patients while routing Medicaid patients to underfunded community clinics with longer wait times and fewer specialists. The result is a two-tier clinical experience: private patients receive care at the main hospital with the newest equipment and shorter appointment intervals, while Medicaid patients are seen at satellite sites with fewer resources.

Physicians working in these systems report that they often prescribe the same drug for both groups but face different administrative barriers. A rheumatologist at a consolidated system in Texas told the author that she writes the same prescription for a biologic for all her patients, but those on Medicaid wait an average of three weeks longer for approval and often receive a different formulation than those with private insurance. The drug itself is the same, but the experience of getting it is not.

A Patient’s Two-Year Wait for a Biosimilar

John D.'s case, mentioned at the start, illustrates the human cost of these systemic gaps. Diagnosed with rheumatoid arthritis in 2022, he was initially prescribed a costly biologic that his commercial insurance covered with a $50 copay. When he lost that coverage in 2023 and enrolled in Ohio Medicaid, his monthly out-of-pocket cost for the same drug jumped to $600. His doctor recommended switching to a biosimilar that had been approved by the FDA in mid-2023 and was quickly added to most private formularies. But Ohio Medicaid did not add the biosimilar to its formulary until early 2026.

During the 30-month gap, John paid over $6,000 out of pocket for the original biologic, relying on a manufacturer coupon program that covered part of the cost but required him to reapply every three months. He missed two doses when the paperwork lapsed, leading to a flare that required a hospitalization. The Kaiser Family Foundation has documented similar stories from at least a dozen states, with patients reporting delays of 18 to 24 months for biosimilars and other newer therapies.

John's story is not a case of a single state being negligent. The lag is built into the Medicaid formulary update process, which typically happens annually and is subject to legislative approval in some states. Manufacturers have limited incentive to negotiate with state programs early, since they can sell the branded drug at a higher price to the private market. The result is a predictable pattern: private patients get the new therapy quickly; public patients wait and pay more.

Policy Levers That Could Close the Gap

Several policy proposals aim to narrow these disparities. A federal out-of-pocket cap for public plans was introduced in Congress in 2025, modeled on the private market limit, but it has not advanced. The Centers for Medicare and Medicaid Services (CMS) is reviewing a rule that would require state Medicaid programs to add new FDA-approved drugs to formularies within six months, mirroring the timeline of private plans. Industry groups have pushed back, arguing that states need flexibility to manage budgets.

State-level drug affordability boards, now active in eight states, have started to set upper payment limits for high-cost drugs, which could reduce the price gap for public plans. Colorado's board, for example, capped the price of several biologics in 2025, leading to lower copays for Medicaid enrollees. Transparency mandates for rebate amounts, passed in four states, have also shown promise by revealing which drugs are being favored for financial rather than clinical reasons.

Medicaid expansion itself could be tied to minimum formulary standards. Some advocates propose that states receiving enhanced federal matching funds must maintain formularies that include all drugs approved in the past 12 months, with exceptions only for safety concerns. This would create a uniform baseline across states, though it would raise costs for states that currently have limited formularies. The trade-off is real: faster access to new drugs means higher short-term spending, even if it reduces long-term complications and costs.

The Role of Manufacturer Coupons and Patient Assistance Programs

Manufacturer coupons and patient assistance programs (PAPs) offer a partial workaround for some patients, but they introduce their own inequities. Private insurers often allow the use of copay coupons, which can reduce a patient's out-of-pocket cost to as little as $5 per month for a specialty drug. However, many state Medicaid programs prohibit the use of manufacturer coupons, citing anti-kickback laws or concerns about driving up overall drug spending. A 2025 survey by the National Association of Medicaid Directors found that 32 states explicitly ban coupon use in their Medicaid managed care plans, leaving enrollees to pay full copays or seek alternative assistance through PAPs.

PAPs themselves are unevenly accessible. They typically require income verification, proof of insurance denial, and reapplication every few months—a process that can be daunting for patients with limited health literacy or unstable housing. A study published in the Journal of the American Medical Association in 2024 estimated that fewer than one in five eligible Medicaid patients actually enrolls in a PAP, largely due to administrative hurdles. For those who do succeed, the assistance may cover only a portion of the cost, and some programs exclude the newest, most expensive drugs. Thus, while coupons and PAPs help some, they do not close the systemic gap; they merely patch it for the most persistent or well-supported patients.

Counterarguments: Why Some Defend the Current System

Not all stakeholders view the disparity as unjust. Some state budget officials argue that Medicaid programs must prioritize cost containment to serve the largest possible number of enrollees. A slower formulary update process, they contend, allows states to negotiate deeper rebates and avoid paying premium prices for drugs whose long-term value is unproven. For example, a 2025 analysis by the National Association of State Budget Officers noted that states that delayed adding certain high-cost biologics saved an average of 15% on drug spending compared with states that added them immediately. These savings, in theory, can be redirected to other services such as primary care or mental health.

Another argument is that private plans have stronger incentives to manage drug costs because they compete for enrollees on the basis of premiums and out-of-pocket limits. Medicaid programs, by contrast, operate under fixed budgets and cannot easily raise premiums or drop coverage. Proponents of the status quo claim that forcing Medicaid to match private formularies would lead to higher taxes or reduced benefits elsewhere. However, critics counter that this reasoning ignores the long-term costs of delayed treatment—hospitalizations, disability, lost productivity—which often exceed the savings from delayed formulary inclusion. A 2024 study in the New England Journal of Medicine estimated that for every dollar saved by delaying a biologic for rheumatoid arthritis, the health system incurs roughly $2.30 in additional costs over the next three years due to flares and complications.

What Clinicians and Patients Can Do Now

While policy changes take time, clinicians and patients have practical options. Before prescribing a new drug, physicians can check state drug assistance programs, which often provide free or discounted medications to low-income patients. Many states have such programs but they are underutilized. Using generic or biosimilar alternatives when available can also reduce out-of-pocket costs, though clinicians must navigate the same formulary restrictions as their patients.

Documenting denials systematically is essential for appeals and for advocacy. Some nonprofit patient resource centers, such as the Patient Advocate Foundation, can help patients navigate the appeals process and find manufacturer coupons. Clinicians can also push their clinic leadership to negotiate direct rebates with manufacturers, a strategy that some large health systems have used to secure lower prices for their Medicaid patients.

The disparities described here are not inevitable. They are the product of a fragmented system that treats insurance type as a proxy for clinical need. Until federal or state policy imposes uniform standards, patients like John D. will continue to pay the price—in dollars, in delayed care, and in worsened health. The evidence is clear, but the political will to act remains uncertain.

This article is for informational purposes only and does not constitute professional medical or legal advice. Readers should consult their healthcare provider or insurance plan for guidance specific to their situation.