Behind every prescription you fill, a company you have probably never heard of is pulling the strings on what you pay. A PBM in healthcare stands for pharmacy benefit manager, and these intermediaries process nearly every prescription claim in the United States. Three companies control roughly 80 percent of the market, yet most patients cannot name a single one. Understanding what PBMs do, and how they profit, is essential to making sense of American drug pricing.
What PBMs Actually Do
Pharmacy benefit managers serve as middlemen between health insurers, drug manufacturers, and pharmacies. Their core functions include negotiating drug prices with manufacturers, building formularies that determine which drugs plans cover, processing prescription claims at the point of sale, and managing pharmacy networks.
When you hand your insurance card to a pharmacist, the PBM’s system processes the transaction in real time. It checks your coverage, applies your copay, and tells the pharmacy how much it will be reimbursed. This entire exchange happens in seconds, but the business arrangements behind it are enormously complex. For a foundational overview, our PBM explainer covers the basics in detail.
The Big Three: Market Concentration
Three PBMs dominate the industry. CVS Caremark (owned by CVS Health), Express Scripts (owned by Cigna), and OptumRx (owned by UnitedHealth Group) together manage pharmacy benefits for approximately 270 million Americans. According to KFF, this concentration raises concerns about market power and its effects on drug pricing, pharmacy reimbursement, and patient access.
Each of these PBMs is vertically integrated with a health insurer and either a pharmacy chain or a healthcare delivery system. CVS Health owns both the PBM (Caremark) and the pharmacy chain (CVS Pharmacy), plus the insurer Aetna. Cigna owns Express Scripts. UnitedHealth Group owns OptumRx alongside UnitedHealthcare insurance and Optum’s medical practices. Critics argue this integration creates conflicts of interest. Proponents say it drives efficiency.
How PBMs Influence Drug Prices
Rebates sit at the center of the PBM pricing controversy. Drug manufacturers pay rebates to PBMs in exchange for favorable formulary placement. A manufacturer might offer a 40 percent rebate on a $500 drug to ensure it lands on a preferred tier, giving it an advantage over competitors.
The question of who benefits from these rebates is fiercely debated. PBMs say they pass most rebate savings to plan sponsors in the form of lower premiums. Critics, including the FTC, have found that a significant portion of rebate revenue is retained by PBMs or flows in ways that do not reduce the patient’s out-of-pocket cost at the pharmacy counter. When your copay is based on the drug’s list price rather than the net price after rebates, you pay more than you would in a transparent pricing system.
Spread Pricing
Spread pricing is another revenue mechanism. A PBM charges a health plan one price for a drug and reimburses the pharmacy a lower price, keeping the difference. For example, the PBM might charge the plan $100 for a generic medication and reimburse the pharmacy $30, pocketing a $70 spread. This practice has been documented extensively in state audits, particularly in Medicaid managed care programs. According to NCSL, multiple states have banned or restricted spread pricing in their Medicaid programs after audits revealed the extent of the practice.
PBMs and Formulary Design
Your formulary, the list of drugs your plan covers and the tier each drug sits on, is designed by the PBM. Formulary decisions blend clinical evidence with financial considerations. A Pharmacy and Therapeutics (P&T) committee of physicians and pharmacists evaluates drugs for safety and efficacy. But the final tier placement also reflects the rebates and discounts the PBM has negotiated.
This creates a dynamic where a clinically equivalent drug with a higher rebate may receive preferred status over a competitor that costs less at the pharmacy counter. The patient may end up paying more because the PBM’s incentive structure favors the higher-list-price drug with the bigger rebate. According to a report from the Congressional Budget Office, reforming rebate structures could shift costs between different parts of the healthcare system in complex ways.
Impact on Independent Pharmacies
Independent pharmacies bear a disproportionate burden of PBM practices. A PBM in healthcare sets the reimbursement rates pharmacies receive, and independent pharmacists have reported that reimbursements frequently fall below their acquisition costs for certain drugs. This phenomenon, sometimes called underwater reimbursement, forces pharmacies to fill prescriptions at a loss.
Network adequacy rules require PBMs to maintain sufficient pharmacy access, but the terms of participation can be take-it-or-leave-it. According to the National Community Pharmacists Association, pharmacy closures have accelerated in recent years, with PBM reimbursement practices cited as a contributing factor. Rural communities are especially vulnerable, as the loss of an independent pharmacy may leave residents without any nearby access to prescription services.
Regulatory Landscape
PBM regulation is evolving rapidly at both the state and federal level. At least 40 states have enacted some form of PBM legislation, ranging from licensing requirements to transparency mandates. Common provisions include requiring PBMs to report aggregate rebate data, banning spread pricing in state-funded programs, and establishing appeals processes for pharmacies that dispute reimbursement rates.
Federal action has been slower but is gaining momentum. The FTC launched a major investigation in 2022, and its interim report raised serious concerns about anticompetitive practices. Bipartisan legislation in Congress has proposed requiring PBMs to pass rebates directly to patients at the point of sale, which would fundamentally reshape how patients experience drug pricing.
For more on how policy developments affect your prescription costs, explore our healthcare policy guide.
How PBMs Affect You Directly
Even if you never interact with your PBM directly, their decisions shape your healthcare experience in concrete ways. The drugs on your formulary, the copay you pay, the pharmacy where you can fill your prescription, and whether your medication requires prior authorization are all determined or heavily influenced by your PBM.
Practical steps you can take include checking your formulary before your doctor prescribes a new medication, asking about therapeutic alternatives when a drug is on a high tier, using preferred pharmacies to minimize copays, and requesting 90-day mail order supplies for maintenance medications. These actions work within the PBM system to reduce your costs without requiring systemic change.
Frequently Asked Questions
What does PBM stand for in healthcare?
PBM stands for pharmacy benefit manager. These companies manage prescription drug benefits on behalf of health insurers, employers, and government programs. For a comprehensive explanation, see our article on PBM meaning.
Are PBMs good or bad for patients?
The answer depends on perspective. PBMs reduce costs for plan sponsors through rebate negotiation and utilization management. However, critics argue that PBM practices can increase out-of-pocket costs for patients and limit pharmacy access. The debate is ongoing and heavily influenced by industry stakeholders.
Can I choose my own PBM?
Generally, no. Your employer or insurer selects the PBM as part of the health plan. You can influence this indirectly by choosing between health plan options during open enrollment, if your employer offers multiple options with different PBMs.
How do PBMs make money?
PBMs generate revenue through retained rebates, spread pricing, administrative fees charged to plan sponsors, and pharmacy dispensing through their own mail order and specialty pharmacies. The exact revenue mix varies by company and contract.
Why are PBMs controversial?
Controversy centers on transparency, market concentration, and the alignment of PBM incentives with patient interests. The FTC and multiple Congressional committees have examined whether PBM practices contribute to high drug prices rather than reducing them.
Understanding the System You Are In
A PBM in healthcare is an unavoidable part of the American prescription drug system. While you cannot choose or replace your PBM, you can navigate the system more effectively by understanding how it works. Know your formulary, use preferred pharmacies, and do not accept a coverage denial without exploring the appeals process. The more informed you are about PBM mechanics, the better positioned you are to minimize your costs and maximize your coverage. For related topics, read our guides on what PBM means and the CVS Caremark PBM.