For patients with relapsed or refractory blood cancers, chimeric antigen receptor T-cell therapy (CAR-T) represents a powerful option. But before a single cell is infused, a prior authorization process can determine whether the treatment even begins. New data suggest that where a patient receives care—specifically, which hospital network oversees their case—strongly influences whether that authorization is granted. Denial rates for CAR-T range from roughly 10% at some academic centers to over 30% at smaller community hospitals, according to analyses presented at the 2024 ASCO Annual Meeting. These differences persist even after adjusting for patient age, disease stage, and comorbidities, pointing to structural factors within hospital networks rather than clinical appropriateness alone.

A Two-Tier Approval System Emerges

Academic medical centers and large cancer institutes often have dedicated prior authorization teams that prepare appeals and communicate directly with insurers. These teams know the specific documentation required for CAR-T—such as evidence of prior chemotherapy failure and measurable disease burden—and can submit complete packets quickly. In contrast, community hospitals with fewer resources may lack such specialized staff, leaving physicians to navigate the paperwork themselves. A 2024 survey of oncology practices found that academic centers secured initial approval for CAR-T in a median of 7 days, versus 21 days at community hospitals.

The discrepancy is not simply a matter of patient volume. Even after controlling for the number of CAR-T cases per year, network-level differences remain. A study led by Dr. Justin Bekelman at the University of Pennsylvania analyzed Medicare claims from 2018 to 2023 and found that denial rates varied more by hospital network than by patient demographics. This suggests that institutional processes—such as how thoroughly a hospital documents a patient's disease history—play a major role. As one hematologist put it, “The difference between approval and denial often comes down to how well the hospital tells the patient’s story.”

Patients at smaller hospitals face additional hurdles. Some networks require multiple internal approvals before even submitting to the insurer, adding days or weeks. Others lack electronic health record integration that automatically populates required fields, increasing the chance of clerical errors. The result is a system where a patient’s zip code can influence whether they receive a potentially life-saving therapy within the window of clinical eligibility.

This two-tier system raises equity concerns. Rural patients, who are more likely to be treated at community hospitals, already face longer travel distances for CAR-T infusion centers. When prior authorization delays compound those geographic barriers, the gap widens. A 2022 study in the Journal of Clinical Oncology, “Rural-Urban Disparities in Access to CAR-T Therapy,” found that patients in rural areas waited an average of 35 days from referral to CAR-T infusion, compared to 18 days for urban patients treated at academic centers.

Why Hospital Network Matters for Prior Authorization

Large hospital networks often negotiate contracts with insurers that include more favorable prior authorization terms. For example, some contracts specify that certain high-cost therapies like CAR-T are automatically covered if the hospital is a designated Center of Excellence. Smaller networks may not have such provisions, leaving them subject to standard review processes that are more likely to result in denials. Additionally, large networks can afford to employ staff whose sole job is to track changing coverage criteria across dozens of insurers.

Community hospitals, by contrast, often rely on physicians to handle prior authorizations between patient visits. A 2023 survey by the Medical Group Management Association (MGMA), “Prior Authorization Burden in Oncology Practices,” found that physicians spend an average of 14 hours per week on prior authorization tasks. In oncology, where treatment decisions are time-sensitive, this administrative burden can delay care. One community oncologist reported that a single CAR-T denial required 12 hours of phone calls and appeals to overturn.

Formulary restrictions further complicate matters. Even when a hospital network is part of a larger health system, insurers may limit CAR-T to specific contracted infusion centers. If a patient’s local hospital is not in-network for CAR-T infusion, the insurer may deny the authorization outright, forcing patients to travel or seek care elsewhere. This creates a patchwork of access that depends on both the hospital's network and the patient's insurance plan.

Physicians across settings report that the criteria used by insurers are inconsistently applied. One insurer may require a minimum CD19 expression level on tumor cells, while another does not. Some demand that patients have failed at least two prior lines of therapy, while others accept one. Without standardized criteria, hospitals with more experience in CAR-T are better equipped to anticipate and meet these varying requirements.

The Cost of Denial: Delays and Worse Outcomes

For patients with aggressive hematologic malignancies, every week of delay can allow disease progression. A study published in Blood Advances in 2024 found that patients who experienced a prior authorization denial for CAR-T had a median delay of 28 days compared to those with initial approval. During that time, 12% of patients became ineligible for CAR-T altogether due to worsening organ function or rapid disease growth. Among those who eventually received therapy, overall survival was significantly lower in the delayed group.

Bridge therapy—chemotherapy or targeted agents given while awaiting CAR-T—is often less effective than the intended treatment. In some cases, bridge therapy itself can cause toxicity that delays CAR-T further. One retrospective analysis from MD Anderson Cancer Center reported that patients who required bridge therapy had a higher rate of hospitalization and a lower likelihood of achieving complete remission after CAR-T infusion. The added cost of bridge therapy, often not fully covered, can also strain patients financially.

Rural patients face a double burden: not only are they more likely to experience denial-related delays, but they also have limited access to clinical trials or alternative therapies if CAR-T is denied. A 2025 report from the Rural Health Research Gateway, “Barriers to Cancer Care in Rural Communities,” noted that rural Medicare beneficiaries with lymphoma were 40% less likely to receive CAR-T than their urban counterparts, even after adjusting for disease severity. Prior authorization denials contributed to this disparity.

The emotional toll is also significant. Patients and families describe the authorization process as a second diagnosis—a period of uncertainty that compounds the anxiety of cancer. For those who are ultimately denied, the sense of having a treatment dangled and withdrawn can be devastating. Some patients pursue appeals, but the legal process is slow and rarely successful without institutional support.

Insurer Policies Drive the Disparity

Medicare Advantage plans, which now cover roughly half of all Medicare beneficiaries, have been shown to have higher prior authorization denial rates for cancer therapies than traditional Medicare. A 2024 analysis by the Kaiser Family Foundation, “Medicare Advantage Prior Authorization Denials for Cancer Treatments,” found that Medicare Advantage plans denied 18% of prior authorization requests for CAR-T, compared to 8% under traditional Medicare. The reasons for denial often included “not medically necessary” or “insufficient documentation,” even when clinical guidelines supported the request.

Some insurers require step therapy—trying a less expensive treatment before CAR-T—even when evidence suggests the alternative is unlikely to work. For patients with multiply relapsed disease, this can mean weeks on an ineffective drug while their cancer progresses. Professional societies, including the American Society of Hematology, have publicly opposed step therapy for CAR-T, arguing that it contradicts established treatment pathways.

Coverage criteria for CAR-T are not always publicly available. Insurers may update their policies without notice, leaving hospitals to discover changes only when a claim is denied. A 2023 investigation by ProPublica, “The Hidden Rules of Insurance Denials,” found that several large insurers had internal guidelines that were more restrictive than those published on their websites. This lack of transparency makes it difficult for hospitals to prepare accurate submissions.

Denial rates for CAR-T vary widely by insurer. Some plans with a high market share in certain regions have been reported to deny over 30% of initial requests, while others approve more than 90%. These differences are not explained by patient mix alone. Hospitals that treat a high proportion of patients from a particular insurer may become adept at meeting that insurer's criteria, but smaller networks lack the volume to develop such expertise.

How Hospitals Game the System

In response to high denial rates, some hospital networks have developed strategies to pre-authorize patients before they meet full clinical criteria. For example, a patient with early relapse may be submitted for CAR-T authorization even before they have exhausted all alternative therapies, so that approval is in hand when needed. This practice, sometimes called “proactive authorization,” can reduce delays but may also lead to denials if the insurer deems the request premature.

Peer-to-peer reviews—where the treating physician speaks directly with an insurer’s medical director—are another tool. These conversations can overturn denials in about 40% of cases, according to a 2025 study in JAMA Network Open. However, the success of peer-to-peer reviews depends heavily on the physician’s familiarity with the evidence and the insurer’s willingness to listen. Community oncologists, who may handle only a few CAR-T cases per year, are at a disadvantage compared to academic specialists who present such cases regularly.

Legal appeals are rare but can be effective. Under Medicare, patients have the right to an expedited appeals process for life-threatening conditions. However, only a small fraction of denials are appealed, partly because patients and clinicians are unaware of the option or lack the resources to pursue it. A 2024 report from the Government Accountability Office found that fewer than 5% of Medicare Advantage denials for cancer treatments were appealed, and of those, about half were overturned.

Hospital consolidation may paradoxically reduce patients' bargaining power. When a large health system acquires a community hospital, the newly merged entity may adopt the insurer contracts of the larger partner, which could include more restrictive formularies. Alternatively, consolidation can give the system more leverage to negotiate better prior authorization terms. The net effect depends on the specific market and contracts, but patients may not see a benefit if the system prioritizes cost containment over access.

Policy Fixes on the Horizon

The Centers for Medicare & Medicaid Services (CMS) has proposed rules to streamline prior authorization for cell and gene therapies, including CAR-T. A 2025 proposed rule would require Medicare Advantage plans to respond to standard prior authorization requests within 7 days and expedited requests within 72 hours, down from current averages of 14 and 5 days respectively. The rule also mandates that plans publicly post their coverage criteria and denial reasons.

Bipartisan legislation in Congress, the Improving Seniors’ Timely Access to Care Act, would require electronic prior authorization processes for Medicare Advantage plans and establish real-time tracking. The bill passed the House in 2024 but stalled in the Senate. If enacted, it could reduce the administrative burden on hospitals and speed up approvals. Similar bills have been introduced in several states, with California and New York passing laws that require faster turnaround for cancer drug authorizations.

Some experts argue that the real solution lies in eliminating prior authorization for certain high-value, time-sensitive treatments altogether. A 2023 white paper from the Brookings Institution proposed that CAR-T and other cell therapies be exempt from prior authorization when administered at accredited centers. Insurers have resisted, citing cost concerns—CAR-T can cost US$400,000 or more per infusion—but proponents note that delays often lead to more expensive hospitalizations and worse outcomes.

Transparency is a common thread in many proposed fixes. If insurers were required to publish their clinical criteria and denial rates by hospital, hospitals could better prepare and patients could make informed choices. Some states, including Texas and Massachusetts, have begun collecting and publishing prior authorization data for cancer therapies, though the data remain incomplete. Real-time data sharing between insurers and hospitals could also flag missing information before a denial occurs.

What This Means for the Practicing Clinician

For clinicians who refer patients for CAR-T, understanding their hospital network’s denial rate is a first step. Some hospitals publish this data internally; others may share it upon request. Knowing which insurers are more likely to deny can help in setting patient expectations and planning alternative timelines. Building relationships with the hospital’s utilization management team can also streamline the process—a quick call to a prior authorization specialist can clarify documentation requirements before submission.

Documentation is critical. When writing a prior authorization request, clinicians should explicitly state the urgency and include all required clinical details: number of prior therapies, dates of relapse, measurable disease, and performance status. Using standardized templates that match insurer criteria can reduce errors. Some electronic health records now offer prior authorization modules that auto-populate fields, but these are not yet widespread.

Social workers and patient navigators can play a key role in supporting patients through the process. They can help patients understand their insurance benefits, identify whether an appeal is warranted, and connect them with legal aid if needed. For patients facing delays, social workers can also arrange bridge therapy or clinical trial options. A 2025 study in the Journal of Oncology Practice found that practices with dedicated navigation teams had 30% shorter prior authorization times for CAR-T.

Finally, clinicians should advocate for policy changes at the institutional and state levels. Joining hospital committees that negotiate insurer contracts, testifying at state hearings, or participating in professional society advocacy can push for more transparent and timely authorization processes. The disparities in CAR-T access are not inevitable—they are the product of a fragmented system that can be reformed. But until those reforms arrive, the burden falls on clinicians and patients to manage the current system as best they can.

This article is for informational purposes only and does not constitute medical or legal advice. Always consult with a qualified healthcare provider regarding your individual situation.