10 Essential PBM Terms Every Requestor Should Know Before Selecting a PBM

If your organization is beginning to evaluate a Pharmacy Benefit Manager (PBM), the vocabulary can feel like a barrier before procurement even begins.

For health plans, coalitions, unions, specialty pharmacies, employer groups, and procurement teams, referred to as requestors moving forward, selecting a PBM may involve unfamiliar pricing benchmarks, clinical controls, network arrangements, and contract definitions. A proposal can look complete and professional while still being difficult to evaluate if the reader does not understand the terms behind the numbers.

This is one reason PBMs can feel complicated to compare. A requestor may see terms such as rebate, formulary, Maximum Allowable Cost, spread pricing, or prior authorization throughout a bid or contract, but each term affects a different part of the pharmacy benefit.

The good news is that requestors do not need to learn every detail of PBM operations before beginning an evaluation. They do need to understand the PBM terms that can materially affect cost, member access, service expectations, and contract performance.

Here are ten of the most important PBM terms to know before reviewing an offering, issuing a Request for Proposal (RFP), or entering contract discussions.

1. Plan Sponsor

A plan sponsor is the organization financially responsible for providing or funding the prescription drug benefit for covered individuals. A plan sponsor may be a self-funded employer, an insurance company, a union health plan, or another entity responsible for prescription drug costs under a pharmacy benefit plan.

This term matters because the plan sponsor is typically the organization whose financial and operational interests the PBM arrangement is expected to support.

Not every requestor is necessarily a plan sponsor. For example, a procurement team, advisor, or other organization may participate in evaluating PBM offerings without directly bearing the prescription drug costs. Understanding this distinction is important when reviewing contracts, reporting responsibilities, guarantees, and pricing arrangements.

In a PBM bid or contract, look for: Which entity is identified as the plan sponsor, which responsibilities belong to that organization, and whether the reporting and financial terms are designed around its needs.

2. Formulary

A formulary is the list of prescription drugs covered or preferred under a pharmacy benefit plan, along with the conditions that may apply to coverage.

A formulary can influence which drugs members can access easily, which drugs carry lower or higher cost sharing, and whether certain drugs require additional approval or clinical steps before they are covered.

Formularies are often organized into tiers. A preferred generic medication may be placed on a lower-cost tier, while a non-preferred brand medication may be placed on a higher-cost tier. Some drugs may not be included at all, except through an exception process.

When comparing PBMs, requestors should not evaluate a formulary only as a list of covered medications. The formulary can affect member disruption, clinical flexibility, rebate arrangements, specialty drug strategy, and total pharmacy benefit cost.

In a PBM bid or contract, look for: Whether the formulary is standard or customizable, how formulary changes are communicated, what exception processes apply, and how the PBM explains the relationship between formulary placement, cost, and member access.

3. Rebate

A rebate is a post-sale price concession or payment associated with the purchase, dispensing, or use of prescription drugs. In PBM arrangements, rebates are often negotiated with drug manufacturers and may be tied to formulary placement, utilization, volume, market share, or other contractual conditions.

Rebates are one of the PBM terms most likely to attract attention because they can materially affect the financial value of an arrangement. But a large rebate guarantee does not automatically mean a proposal offers the lowest overall cost or the best fit for the requestor.

A requestor needs to understand how rebates are defined, whether they are passed through, how they are reconciled, what exclusions apply, and whether the arrangement creates tradeoffs elsewhere, such as formulary design or drug mix.

In a PBM bid or contract, look for: The definition of rebate, any guaranteed amounts, the timing of payments, retained amounts or administrative fees, exclusions, reconciliation methods, and the reporting needed to verify performance.

4. Maximum Allowable Cost (MAC)

Maximum Allowable Cost (MAC) generally refers to the maximum reimbursement amount established for certain prescription drug products, often generic or multi-source medications.

In plain language, a MAC list can help determine how much a pharmacy is reimbursed for dispensing a covered drug. This matters because pharmacy reimbursement and requestor cost are related, but they are not always the same figure.

MAC pricing may affect pharmacy participation, member access, generic drug economics, pharmacy appeals, and the overall pricing model offered by a PBM. Different PBMs may use different MAC lists, update schedules, appeals processes, or pricing methodologies.

For a requestor new to PBM evaluation, MAC can be difficult because it sounds like a single price when it is really part of a broader reimbursement framework.

In a PBM bid or contract, look for: Who maintains the MAC list, how frequently it is updated, whether it applies to the requestor’s pricing, what pharmacy appeal process exists, and whether the PBM clearly distinguishes what the requestor pays from what the pharmacy receives.

5. Average Wholesale Price (AWP)

Average Wholesale Price (AWP) is a published prescription drug pricing benchmark that has historically been used in pharmacy reimbursement and contract pricing formulas.

Despite its name, AWP should not automatically be interpreted as the actual average price paid by pharmacies to acquire a drug. It is a benchmark, and its usefulness depends on how it is used in the pricing arrangement.

A PBM proposal might express certain discounts as “AWP minus” a percentage. For example, a proposal could describe retail brand pricing through a discount off AWP. That number may be important, but it should not be reviewed in isolation. The requestor still needs to understand dispensing fees, rebates, specialty drug terms, network arrangements, exclusions, and the benchmark used for different drug categories.

AWP is useful to understand because it may appear prominently in pricing exhibits while not representing the final net cost to the requestor.

In a PBM bid or contract, look for: Which products or channels use AWP-based pricing, what discount is applied, whether dispensing fees are separate, what exclusions exist, and how AWP-based terms interact with rebate and specialty drug arrangements.

6. Wholesale Acquisition Cost (WAC)

Wholesale Acquisition Cost (WAC) is a manufacturer list price for a drug sold to wholesalers or direct purchasers, before certain discounts, rebates, or other price reductions are applied.

WAC may appear in a PBM contract or pricing exhibit as a reference point for certain drug pricing arrangements, particularly where another benchmark is unavailable or where specialty or limited-distribution drug terms require a different approach.

Like AWP, WAC is not automatically the final cost paid by a requestor or member. It is a reference price. A complete evaluation needs to consider what fees, discounts, rebates, contractual adjustments, or service arrangements apply alongside it.

For new requestors, the important lesson is simple: a pricing benchmark is not the same thing as net cost. A strong PBM comparison requires understanding both the benchmark and the adjustments layered around it.

In a PBM bid or contract, look for: Where WAC applies, whether pricing is expressed as WAC plus or minus an adjustment, what products are included, and whether the benchmark is being used consistently across competing proposals.

7. Claims Adjudication

Claims adjudication is the process used to evaluate and process a pharmacy claim when a prescription is presented for coverage.

When a member goes to a pharmacy, the claim is submitted electronically and evaluated against benefit rules. The process may determine whether the member is eligible, whether the drug is covered, what cost sharing applies, whether utilization management requirements exist, whether the pharmacy is in network, and what payment or rejection response is returned.

Claims adjudication is central to member experience because it is where the benefit becomes real. A contract can describe strong service and broad capabilities, but members experience the pharmacy benefit when a prescription successfully processes or when a claim is delayed, rejected, or requires further action.

Requestors should understand how PBMs manage claims processing, accuracy, system availability, rejected claims, customer support, and reporting.

In a PBM bid or contract, look for: Claims accuracy guarantees, processing standards, system availability, reporting capabilities, rejected-claim support, real-time edits, and responsibilities for resolving member or pharmacy issues.

8. Spread Pricing

Spread pricing is a pricing arrangement in which the amount paid by the plan sponsor to the PBM for a prescription is greater than the amount reimbursed by the PBM to the pharmacy for that same prescription, with the difference retained according to the arrangement.

Spread pricing is not simply a vocabulary issue. It is a contract design issue. Some requestors may consider arrangements involving spread pricing, while others may prefer a model that separately identifies administrative compensation or pharmacy reimbursement.

The important point is not to assume that any one term tells the entire story. Requestors need to understand how the PBM is compensated, whether spread pricing applies, where it applies, what reporting is provided, and how the financial model compares with other offerings.

This is also why PBM comparison can become difficult. Two proposals may use different compensation structures even when both appear competitive at a high level.

In a PBM bid or contract, look for: Whether spread pricing is permitted, prohibited, disclosed, or limited; how pharmacy reimbursement relates to requestor charges; and what audit or reporting rights help the requestor verify the arrangement.

9. Prior Authorization (PA)

Prior Authorization (PA) is a utilization management requirement under which approval must be obtained before coverage is provided for certain prescription drugs or uses.

Prior authorization may be used to support appropriate use, evaluate clinical criteria, manage safety concerns, or ensure that coverage aligns with the plan’s benefit design. For members and prescribers, however, PA can also affect how quickly a medication is accessed.

For requestors, prior authorization should be evaluated from both a clinical and operational perspective. It may help manage utilization, but the details matter: which drugs require PA, how requests are submitted, how quickly decisions are made, how exceptions are handled, and what support is available to prescribers and members.

A PBM proposal that discusses prior authorization only in broad terms may not give a requestor enough information to assess member impact.

In a PBM bid or contract, look for: Drug categories subject to PA, clinical review criteria, decision turnaround times, appeal or exception pathways, reporting, and support for members and prescribers.

10. Step Therapy

Step therapy is a utilization management approach that may require a member to try one medication before coverage is approved for another medication, typically when the first option is expected to be clinically appropriate and more cost effective.

Step therapy is sometimes described as a “step edit” or “fail first” requirement. The purpose is generally to guide initial treatment toward appropriate preferred options before moving to alternatives that may be more costly or otherwise reserved for particular clinical situations.

Like prior authorization, step therapy is not inherently positive or negative in every context. Its effect depends on clinical design, exception processes, member population, therapeutic category, and how quickly medical necessity issues can be resolved.

Requestors should understand how step therapy affects access, how exceptions are reviewed, and whether the PBM can report on member experience and clinical outcomes related to these programs.

In a PBM bid or contract, look for: Which drug classes are subject to step therapy, required steps, exception criteria, prescriber support, turnaround times, member communication, and reporting.

A Real-World Inspired Scenario: How PBM Terms Show Up in a Proposal

Imagine a growing organization that is evaluating PBM services for the first time. Its leadership wants predictable prescription drug spending, accessible pharmacy options, and a manageable member experience.

The organization receives two PBM proposals.

The first proposal highlights a strong rebate guarantee and attractive AWP-based discounts. It also includes a standard formulary, a MAC pricing methodology for generic drugs, prior authorization for selected high-cost medications, and step therapy in several therapeutic categories.

The second proposal uses a different formulary, references WAC for certain specialty medications, identifies whether spread pricing applies, and provides different claims adjudication guarantees and member support commitments.

Neither proposal can be judged by one headline number.

A higher rebate may be connected to a different formulary. A deeper AWP discount may not capture the full net-cost picture. A MAC methodology may affect pharmacy reimbursement and network experience. Prior authorization and step therapy may affect member access. Claims adjudication standards may affect day-to-day service. Spread pricing terms may change how the requestor understands PBM compensation.

This is why understanding PBM terms matters before a requestor reaches contract negotiation.

Without a working vocabulary, a requestor may compare marketing claims or isolated numbers. With a working vocabulary, the requestor can ask stronger questions:

• What is actually covered under the formulary?
• How are rebates defined and reconciled?
• Which pricing benchmarks apply to which drugs?
• Does spread pricing occur under this arrangement?
• How do MAC terms affect reimbursement and reporting?
• How do prior authorization and step therapy affect members?
• What claims adjudication guarantees protect service quality?
• Which organization is financially responsible as the plan sponsor?

These are not technical questions for the sake of sounding informed. They are practical questions that reveal how a PBM offering may work in the real world.

These 10 PBM Terms Are Only the Beginning

These ten terms are not a complete PBM glossary. They are a practical starting point for requestors beginning to evaluate pharmacy benefit offerings.

The PBM industry has an extensive vocabulary covering pricing, rebates, formularies, networks, specialty pharmacy, clinical management, audits, guarantees, reporting, implementation, contracting, and member service. Terms that appear routine to experienced PBM professionals can materially affect the cost, access, accountability, and long-term performance of an arrangement.

That is why requestors should not treat PBM terminology as background reading. Definitions shape comparison. The meaning of a rebate, pricing benchmark, formulary rule, utilization management requirement, or compensation model can change how an offering should be evaluated.

A requestor does not need to master every PBM term before beginning the process. But it should have enough working knowledge to identify what matters, ask informed questions, and recognize when two proposals that sound similar may operate very differently in practice.

Rapid Request will continue publishing educational resources that explain the terminology, pricing structures, procurement challenges, and evaluation questions requestors encounter when engaging PBMs.

For now, these ten terms provide a strong foundation: understand the language first, then compare the offering behind it.