Pharmacy Benefit Manager Transparency: What Mid-Market Employers Should Demand From Their Drug Plan

Every time one of your employees fills a prescription, a pharmacy benefit manager sits in the middle of that transaction collecting a fee, retaining a share of drug manufacturer rebates, and in some contract structures, profiting from the spread between what it pays the pharmacy and what it bills your plan. Most mid-market employers know they have a pharmacy benefit manager embedded in their health coverage. Far fewer understand how that manager earns its income, what that means for your total drug spend, or what leverage you have as a plan sponsor to demand better terms. For employers with 50 to 500 employees, pharmacy costs now represent 20 to 30 percent of total health plan spend. A systematic transparency review of your PBM contract and plan design, combined with targeted formulary changes, routinely recovers 12 to 20 percent of that cost line without reducing the coverage your employees receive.

How Pharmacy Benefit Managers Generate Revenue and Why It Matters for Your Plan

Understanding what you are actually paying for when you pay pharmacy benefit management fees requires looking at all three revenue streams operating simultaneously in most traditional contracts. The fee line on your PBM invoice is rarely the full picture of what the manager is earning from your plan.

Retained Rebates

Drug manufacturers pay rebates to pharmacy benefit managers in exchange for favorable formulary placement. When a drug appears in the preferred tier of your formulary, it gets prescribed more often, which generates more volume for the manufacturer. The manufacturer passes a portion of that volume benefit back to the PBM as a rebate. In a traditional retained-rebate model, the PBM keeps all or most of that payment. In a pass-through model, the entire rebate flows to your plan as a credit against drug costs.

For mid-market employers, the difference between a retained-rebate model and a pass-through model can represent several hundred dollars per employee per year in pharmacy cost. The formulary decisions that drove the rebates were made in part based on rebate income potential rather than purely on which drugs are most cost-effective for your population. This is the core conflict at the heart of retained-rebate contracting.

Spread Pricing

In a spread pricing model, the PBM reimburses the pharmacy one amount for a prescription and bills your plan a higher amount, keeping the difference as margin. The plan sponsor typically never sees the reimbursement rate paid to the pharmacy, only the amount billed to the plan. In a pass-through or transparent pricing model, the employer sees both numbers and the PBM earns only the disclosed administrative fee.

Spread pricing is more common in government-administered programs than in mid-market employer plans, but it is not absent from the commercial market. Your contract should specify which pricing model applies and whether the employer has the right to audit the pharmacy reimbursement rates. Absence of explicit audit rights in a contract is a meaningful red flag worth addressing at the next renewal.

Administrative and Clinical Management Fees

The explicit per-member-per-month administrative fee is the most visible element of PBM compensation. It covers claims adjudication, member services, reporting, and pharmacy network management. In a pass-through model where rebates and spread go to the employer, this fee is the PBM's primary revenue source. In a retained-rebate model, this fee is often lower on its face, creating the appearance of cost efficiency while the retained rebates represent the real compensation to the manager.

When comparing PBM proposals, the total cost of ownership requires netting rebate credits against administrative fees and pharmacy reimbursement rates. A proposal with a lower administrative fee but a retained-rebate model may cost significantly more in total than a proposal with a higher fee and full pass-through. This comparison is not possible without obtaining comparable data on expected rebate income under each structure.

The Pass-Through Pricing Decision

The pass-through versus retained-rebate decision is the single highest-impact choice you make in PBM contracting. For most mid-market employers who have not renegotiated their PBM arrangement in the past three years, transitioning to a pass-through model at the next renewal produces a measurable net cost reduction in the first year.

Pass-through pricing creates transparency on three fronts. First, you see the exact rebate your formulary generates because 100 percent of it flows to your plan as a credit. Second, you see the actual pharmacy reimbursement rates because the PBM charges you those rates directly rather than billing a marked-up amount. Third, the PBM compensation is limited to its disclosed administrative fee, which makes the relationship more auditable and easier to benchmark against the market at each renewal.

The counterargument for retained-rebate models is that the PBM formulary management incentives, when properly designed, can push manufacturers toward more aggressive rebate offers in exchange for preferred placement. In theory, a skilled PBM operating on a retained-rebate basis can extract larger rebates than a pass-through manager because its own income depends on it. In practice, this benefit rarely accrues to mid-market employers at a scale that offsets the transparency advantage of knowing what you are actually paying.

A meaningful test is to ask your current PBM for a side-by-side comparison of your actual plan costs under your current contract structure versus what they would be under a pass-through model with equivalent formulary and network terms. A manager unwilling to provide this comparison is a meaningful signal about contract transparency overall.

Formulary Design and Drug Category Prioritization

Your formulary is the list of drugs covered under your health plan and the tier each drug is assigned to, which determines what your employees pay out of pocket. Formulary design directly influences both total plan cost and employee satisfaction, and the two are not inherently in conflict. A well-designed formulary can lower total drug spend by directing utilization toward cost-effective alternatives while maintaining high coverage quality for employees.

Preferred Drug Lists and Tier Structure

Most employer formularies use a three-tier or four-tier structure. Generic drugs occupy the lowest-cost tier, preferred brand drugs occupy the second tier, and non-preferred brand and specialty drugs occupy higher tiers with higher member cost-sharing. The formulary design decisions that matter most for employer cost are which drugs appear in which tier and whether lower-cost alternatives exist at the same therapeutic level.

Generic substitution is the most straightforward cost lever. When a brand drug patent expires and a generic equivalent becomes available, moving member cost-sharing incentives toward the generic can reduce per-claim cost significantly. Brand drugs that still command preferred-tier placement after a generic becomes available are either generating substantial rebates for the PBM or were not reviewed at the most recent formulary update.

Therapeutic alternatives are a more complex formulary lever. Two drugs in the same drug class may produce equivalent clinical outcomes at meaningfully different costs. Formulary tier placement that favors the lower-cost therapeutic equivalent, when supported by clinical evidence, can reduce drug spend without reducing treatment quality. This is an area where working with a pharmacy consultant or benefits advisor who can review your actual utilization data against current therapeutic equivalence evidence adds real value.

Specialty Drug Management

Specialty drugs are the fastest-growing cost category in employer pharmacy benefits. These drugs treat complex or chronic conditions including autoimmune disorders, oncology, and neurological diseases. A single specialty drug can cost tens of thousands of dollars per patient per year, and specialty utilization for even a small employer population can dominate the pharmacy cost line.

Several management strategies exist for specialty drug costs. Site-of-care programs direct specialty drug administration to lower-cost outpatient infusion centers or home infusion settings rather than hospital outpatient departments, which can reduce per-infusion cost by 30 to 50 percent for some drug categories. Specialty pharmacy carve-outs channel specialty prescriptions through a specialty pharmacy vendor with better negotiated rates than the retail network. Patient assistance program coordination helps employees qualify for manufacturer-sponsored assistance programs that reduce the plan direct drug cost.

The prerequisite for all of these strategies is knowing which specialty drugs are in your current utilization. A monthly pharmacy report from your PBM that breaks out specialty spend by drug category is the starting point. If your PBM does not provide this level of reporting as a standard deliverable, requesting it is a reasonable first step before evaluating specialty management programs.

Step Therapy and Prior Authorization as Cost Controls

Step therapy and prior authorization are clinical management programs that affect which drugs get prescribed and when. Employers who understand how these programs work in their plan can use them as meaningful cost controls. Employers who accept whatever defaults their PBM or carrier sets at plan implementation rarely get the full cost benefit these programs can provide.

Step therapy requires that a patient try a less expensive drug first before the plan covers a more expensive alternative in the same therapeutic class. The clinical rationale is that many patients respond well to first-line drugs, and the higher-cost option should be reserved for those who do not. The cost rationale is that reducing utilization of high-cost drugs that are not clinically superior to lower-cost alternatives for most patients meaningfully reduces drug spend over time.

Step therapy can create friction when it requires a patient who has already established effective treatment on a higher-tier drug to restart on a first-line drug before the plan will continue coverage. Most plans include an exceptions process for established patients and for clinical situations where step therapy would create patient harm. The design of this exceptions process affects both cost outcomes and employee satisfaction.

Prior authorization requires the prescribing physician to obtain pre-approval for a drug before the plan will cover it. This is most commonly applied to high-cost brand drugs, specialty drugs, and drugs with significant abuse potential. A well-designed prior authorization program adds a clinical review step that reduces utilization of drugs for which the clinical evidence does not support the specific patient situation. An overly broad prior authorization program creates unnecessary administrative friction for common prescriptions and erodes employee confidence in the benefit.

The calibration of both step therapy and prior authorization programs should be reviewed at each renewal. If your current plan has not been reviewed in three or more years, the program may not reflect current formulary composition, current evidence on therapeutic equivalence, or changes in your employee population utilization patterns.

Audit Rights and What They Make Possible

Audit rights in your PBM contract allow you to verify that the pricing, rebates, and administrative terms you were quoted are what you are actually receiving. Without audit rights, your ability to confirm contract compliance is limited to reviewing the reports the PBM provides, which it produces and controls.

A meaningful audit clause specifies what records you can access, how far back the audit can reach, who bears the cost of the audit process, and what remedies apply if the audit reveals discrepancies. Many standard PBM contracts include audit rights in name but restrict access to aggregate data rather than claim-level detail, which limits the ability to identify specific pricing variances.

Request audit rights that cover: actual pharmacy acquisition cost data for a representative sample of claims, rebate documentation that confirms the amounts remitted versus what was generated, administrative fee reconciliation that confirms per-member-per-month charges against enrolled member counts, and network access confirmation that enrolled employees had access to the network tiers specified in the contract.

Employers who conduct even an informal audit at renewal consistently report finding discrepancies between contracted terms and actual plan charges. These discrepancies are not always material, but they are common enough that building audit rights and exercising them periodically is standard practice for self-funded employers and should become standard practice for mid-market employers in any funding model.

How Mid-Market Employers Renegotiate PBM Contracts

Timing the Renegotiation

PBM contracts typically run one to three years. Renegotiation opportunities are clearest at contract renewal, but mid-term renegotiations are possible when enrollment changes significantly, when a competing proposal creates leverage, or when a material error in contract performance is identified through an audit. If your current contract expires within the next 12 months, beginning the competitive review process now allows time to evaluate alternatives without pressure.

The most effective renegotiations use a formal request-for-proposal process that invites proposals from multiple managers. The existence of competing proposals creates specific pricing benchmarks that your current manager must respond to if they want to retain the account. Without this competitive pressure, renegotiation typically produces incremental improvements rather than structural changes.

What to Request in the Contract

Several contract terms deserve explicit attention in any renegotiation. Pass-through pricing that guarantees 100 percent of manufacturer rebates to the plan should be a baseline request rather than an aspirational target. Ingredient cost guarantees that set a maximum spread between the drug acquisition cost index and your plan reimbursement rate provide protection against spread pricing. Administrative fee caps that limit per-member-per-month charges for specific years of the contract prevent fee escalation between renewals.

Performance guarantees are an underused contract tool for mid-market employers. A well-negotiated PBM contract can include financial performance guarantees tied to generic dispensing rate, formulary compliance rate, and administrative accuracy. If the manager does not meet the guaranteed performance levels, the employer receives a credit against future fees. These guarantees create accountability for the clinical management programs you are paying for and provide a remedial mechanism if performance falls short.

Use the Benefits Savings Strategy Builder to model the net cost impact of moving from your current contract structure to a pass-through model with an assumed rebate credit and administrative fee. The output gives you a baseline expectation to test proposals against and a specific savings figure to present to leadership when making the case for investing time in a full PBM review.

What Improved PBM Terms Are Worth Over a Multi-Year Plan

The case for investing in PBM transparency and renegotiation looks different when you calculate the compound effect over three to five years. A mid-market employer spending $400,000 per year on pharmacy benefits who recovers 15 percent through improved terms generates $60,000 in savings in year one. Over four years with trend-adjusted spend growth, the cumulative savings from that single contract improvement can reach $275,000 to $350,000 without any change to the coverage employees receive.

This is the financial scale of a PBM improvement that most mid-market employers have not yet captured. The largest employers captured these savings years ago by building internal pharmacy expertise or retaining pharmacy consulting firms. Mid-market employers are in a transition period where the data and tools to do the same evaluation are now accessible without an internal pharmacy team or a major consulting engagement.

The Health Funding Projector models total health plan cost trajectories including pharmacy trend, which gives you a baseline projection of where your pharmacy costs are heading under current contract terms versus what an improved contract could produce. For self-funded and captive employers, the pharmacy cost improvement flows directly to the employer annual claims position, affecting captive distributions and stop-loss renewal pricing in addition to the direct premium impact.

For employers reviewing their overall benefits cost structure and considering self-funded or captive arrangements as part of the solution, the pharmacy contract is often the most immediate cost lever available regardless of funding model. A fully insured employer who renegotiates PBM terms at the next renewal captures savings within the current plan year. The transition to a transparent pharmacy contract does not require a funding model change, though a funding model that provides detailed claims reporting makes ongoing pharmacy management significantly more effective.

Related Reading

For additional context on pharmacy benefits and health plan cost management:

• Captive Insurance Annual Distributions: How Mid-Market Employers Earn Back Health Plan Profits
• Employer Health Plan Cost Benchmarking: Setting Renewal Expectations With Industry Data
• Stop-Loss Insurance for Self-Funded Employers: A Practical Guide
• Mid-Year Health Plan Changes: When Employers Can Switch Coverage and What the Process Requires

Frequently Asked Questions

How do I know if my current PBM contract uses a retained-rebate or pass-through model?

Review the contract compensation section for language describing rebate treatment. A pass-through contract will explicitly state that 100 percent of manufacturer rebates are credited to the plan. A retained-rebate contract will describe the PBM right to retain rebates or will list a guaranteed rebate-per-script that caps what the employer receives. If the contract language is ambiguous or absent on this point, ask your broker or the PBM directly for written clarification. The response will tell you quickly whether the manager is comfortable with transparency on this question.

What size employer can realistically negotiate pass-through pricing?

Employers with 50 or more enrolled members can access pass-through pricing, though the terms available to employers with 50 to 150 employees may differ from those available to employers with 200 or more. Group purchasing arrangements and benefits consulting firms that aggregate employer volume can provide smaller employers access to pass-through models that would not be individually negotiable. At renewal, it is always worth requesting a pass-through proposal explicitly, even if your current enrollment is below 100, because the competitive landscape has shifted in employers favor over the past several years.

Can my company conduct a PBM audit without damaging the relationship?

A PBM that responds negatively to a routine audit request is providing useful information about how the relationship will develop. Reputable managers expect to be audited and maintain the records and processes to support audit inquiries. Frame the audit as a standard renewal review rather than an accusation of wrongdoing, use an independent pharmacy consultant if you want an external party to conduct it, and give the PBM a reasonable timeline to respond. In most cases, managers who have been performing within contract terms welcome the audit as an opportunity to demonstrate compliance. If the manager response creates obstacles to audit access, escalate to your broker and document the interaction for use in the renewal negotiation.

What is a reasonable generic dispensing rate benchmark for a mid-market employer plan?

Generic dispensing rates above 85 percent are achievable and represent a reasonable baseline for mid-market employer plans. Rates below 80 percent often indicate formulary design issues, pharmacy network gaps, or prescriber patterns that could be addressed through plan design changes without reducing coverage quality. Your PBM should report your current generic dispensing rate as part of standard quarterly or annual reporting. If this metric is not included in your current reports, requesting it is a straightforward first step in identifying where formulary improvements are possible.

How does improving PBM terms interact with moving to a self-funded or captive funding model?

PBM renegotiation and funding model changes are independent decisions that can be made sequentially or simultaneously. Employers who move to a self-funded arrangement gain access to claim-level pharmacy data that makes ongoing PBM management more effective, because you can see exactly which drugs your employees are using and how much the plan is paying for each claim. Employers who remain fully insured can still negotiate PBM contract terms through their carrier agreement if the plan uses the carrier PBM arrangement, or through a standalone PBM contract if the pharmacy benefit is carved out. The carrier integration question is worth clarifying with your benefits advisor before beginning any PBM renegotiation, since the contract structure differs depending on whether you are negotiating with a carrier or directly with an independent manager.