Pharmaceutical costs are the fastest-growing line item in most employer health plans, and small to mid-sized businesses often feel powerless against annual double-digit increases. You’re not imagining it—drug costs are outpacing general medical inflation, and if you’re a smaller employer, you’re likely paying more per prescription than larger companies with better negotiating leverage.
PEOs offer a structural advantage here. By pooling employee counts across their entire client base, they can access pharmacy benefit managers (PBMs) typically reserved for large employers, negotiate formulary strategies that individual companies can’t touch, and deploy specialty drug management programs that would be cost-prohibitive on your own.
But here’s the thing: not all PEOs approach pharmacy benefits the same way. Some treat it as an afterthought bundled into your health plan. Others use it as a strategic lever to actually contain costs. The difference between a well-structured pharmaceutical strategy and a generic one can mean tens of thousands of dollars annually—sometimes more, depending on your employee count and health profile.
This guide breaks down seven specific strategies PEOs use to contain pharmaceutical costs, what to ask during evaluation, and how to measure whether your current arrangement is actually delivering savings or just masking the problem.
1. Leverage PEO Pooled Purchasing for Tier-1 Drug Pricing
The Challenge It Solves
Small employers typically pay higher per-prescription costs than large employers because they lack negotiating leverage with PBMs. Average Wholesale Price (AWP) discounts and dispensing fees are tiered based on total covered lives, and if you’re operating with 50 or 100 employees, you’re in the lowest tier—meaning you’re paying more for the exact same drugs.
This isn’t a small difference. The pricing gap between a 75-employee company and a 5,000-employee company on the same generic prescription can be substantial, even though the pill is identical.
The Strategy Explained
PEOs aggregate employee counts across their entire client base to access pricing tiers normally reserved for large employers. If your PEO represents 10,000 covered lives across 200 clients, you benefit from the negotiating power of that full pool—not just your own headcount.
This applies to AWP discounts (the percentage off the list price for brand and generic drugs), dispensing fees (the per-prescription administrative charge), and even rebate structures. The larger the pool, the better the terms.
But not all PEOs pool effectively. Some have fragmented arrangements where each client is essentially negotiating separately under the PEO’s umbrella. Others have true pooled contracts where every client benefits from the aggregate volume.
Implementation Steps
1. Ask your PEO directly: “Are your pharmacy benefits fully pooled across all clients, or are we in a separate risk pool based on our size?” If they hesitate or give a vague answer, that’s a red flag.
2. Request specific AWP discount percentages for both brand and generic drugs. Compare these to industry benchmarks for large employers. If your generic AWP discount is below 80%, you’re likely not benefiting from true pooled purchasing.
3. Review your PBM contract terms annually. Pricing tiers change as PEOs grow or lose clients, and your effective discount should improve over time if the PEO is scaling properly. Understanding how PEOs lower health insurance costs can help you evaluate whether your arrangement is truly competitive.
Pro Tips
Don’t assume pooling happens automatically. Some PEOs market pooled purchasing but structure contracts in ways that limit your actual benefit. Get the specific discount percentages in writing, and if your PEO can’t provide them, that tells you everything you need to know about transparency.
2. Negotiate Transparent PBM Pass-Through Contracts
The Challenge It Solves
PBM pricing models fall into two categories: spread pricing and pass-through pricing. Under spread pricing, the PBM charges you one price and pays the pharmacy a lower price, pocketing the difference. You have no visibility into the actual transaction, and the PBM’s incentive is to maximize that spread—not minimize your costs.
Under pass-through pricing, the PBM charges you exactly what they pay the pharmacy, plus a transparent administrative fee. You see the actual ingredient cost, the dispensing fee, and the PBM’s markup. The incentive structure flips: the PBM makes money on volume and service, not on hidden spreads.
Many PEOs default to spread pricing because it’s easier to administer and generates additional revenue for the PBM (and sometimes the PEO). You end up paying more without realizing it.
The Strategy Explained
A transparent PBM pass-through contract ensures you’re paying actual pharmacy costs plus a fixed, disclosed fee. You also get full visibility into manufacturer rebates—money that drug manufacturers pay to PBMs for formulary placement and utilization. In spread pricing models, these rebates often disappear into the PBM’s revenue. In pass-through models, they flow back to you as the plan sponsor.
This isn’t just about principle. Rebates can represent a significant portion of your total pharmacy spend, and if they’re not being passed through, you’re leaving money on the table.
Implementation Steps
1. Ask your PEO: “Is our PBM contract structured as spread pricing or pass-through pricing?” If they don’t know or say it’s proprietary, that’s a problem.
2. Request a rebate guarantee in writing. A legitimate pass-through arrangement will specify a minimum rebate percentage (often expressed as a percentage of brand drug spend) that flows back to you.
3. Review quarterly PBM reporting. You should receive detailed reports showing ingredient costs, dispensing fees, administrative fees, and rebate credits. Following PEO cost reporting best practices ensures you’re getting the transparency you need to verify pass-through arrangements.
Pro Tips
Some PEOs claim to use pass-through pricing but structure it in ways that still hide costs. Look for contracts that specify “100% rebate pass-through” and provide itemized invoicing. If your PEO resists providing this level of detail, it’s worth exploring whether a different PEO or a standalone PBM arrangement would give you better transparency.
3. Implement Specialty Drug Management Programs
The Challenge It Solves
Specialty drugs—typically defined as high-cost medications for complex conditions like cancer, rheumatoid arthritis, multiple sclerosis, and hepatitis C—represent a small percentage of prescriptions but a disproportionately large share of total pharmacy costs. Industry observers note that specialty drugs often account for the majority of pharmacy cost increases for employer-sponsored plans, even though they represent less than 5% of total prescriptions.
For small employers, a single employee on a specialty drug can swing your entire pharmacy budget. Without active management, these costs spiral quickly.
The Strategy Explained
Specialty drug management programs focus on three key areas: site-of-care optimization, prior authorization, and biosimilar substitution.
Site-of-care optimization ensures that infused specialty drugs (medications administered intravenously) are delivered at the lowest-cost appropriate setting. Receiving infusion therapy at a hospital outpatient facility can cost two to three times more than receiving the same treatment at an infusion center or physician’s office.
Prior authorization requires clinical review before high-cost specialty drugs are approved, ensuring the medication is medically necessary and that lower-cost alternatives have been tried first.
Biosimilar substitution encourages the use of biosimilar drugs (highly similar versions of biologic medications) instead of branded biologics when clinically appropriate. Biosimilars can cost significantly less than their branded counterparts, but adoption remains lower than projected due to rebate structures that sometimes favor branded drugs. Companies in the biotech sector often face particularly high specialty drug utilization and can benefit from aggressive biosimilar strategies.
Implementation Steps
1. Confirm your PEO has an active specialty drug management program. Ask specifically: “Do you optimize site-of-care for infused specialty drugs? Do you have a biosimilar-first formulary strategy?”
2. Review your specialty drug utilization reports. Your PEO should provide quarterly data showing which employees are on specialty drugs, where they’re receiving treatment, and whether biosimilar alternatives are available.
3. Implement a specialty pharmacy network requirement. Specialty pharmacies are designed to handle high-cost, complex medications and often provide better adherence support and lower costs than retail pharmacies.
Pro Tips
Don’t wait until you have a high-cost claim to think about specialty drug management. These programs work best when they’re proactive. If your PEO doesn’t have a clear specialty drug strategy, that’s a gap worth addressing before it becomes a budget crisis.
4. Require Formulary Customization Options
The Challenge It Solves
Most PEOs offer a standard formulary—a tiered list of covered drugs—that applies to all clients. This one-size-fits-all approach is administratively simple, but it doesn’t account for the specific health profile of your workforce.
If your employees skew older, you might need better coverage for chronic condition medications. If you have a younger workforce, you might prioritize preventive care and generic fill rates. A generic formulary doesn’t optimize for either scenario, and you end up paying for coverage you don’t need or missing coverage that would reduce long-term costs.
The Strategy Explained
Formulary customization allows you to adjust drug tiers, prior authorization requirements, and step therapy protocols based on your workforce’s actual utilization patterns. This doesn’t mean building a formulary from scratch—that’s impractical for most small employers—but it does mean having flexibility to adjust coverage for high-impact drug categories.
For example, if your utilization data shows high spend on diabetes medications, you might move certain generic diabetes drugs to a lower tier to encourage adherence and reduce long-term complications. If you have low specialty drug utilization, you might implement stricter prior authorization to prevent unnecessary high-cost claims.
Implementation Steps
1. Ask your PEO: “Can we customize our formulary based on our workforce’s health profile, or are we locked into a standard formulary?” If customization is available, ask what level of flexibility exists.
2. Review your drug utilization data to identify high-impact categories. Look for chronic condition medications with high spend, low generic fill rates, or opportunities for therapeutic substitution.
3. Work with your PEO to implement targeted formulary adjustments. Start with one or two high-impact categories rather than trying to overhaul the entire formulary at once. Understanding benefits administration outsourcing can help you determine how much customization your PEO can realistically support.
Pro Tips
Formulary customization requires data. If your PEO can’t provide detailed drug utilization reports, you won’t have the information needed to make informed adjustments. This is another area where transparency matters—not just for cost containment, but for strategic decision-making.
5. Deploy Pharmacy Benefit Carve-Out Analysis
The Challenge It Solves
Most PEOs bundle pharmacy benefits with medical coverage, which simplifies administration but doesn’t always deliver the best value. Bundled arrangements can hide inefficiencies, limit your ability to negotiate directly with PBMs, and lock you into pricing structures that don’t optimize for your specific utilization patterns.
For some employers, a standalone PBM arrangement (where you contract directly with a PBM outside the PEO) delivers better pricing, more transparency, and greater flexibility. For others, the administrative complexity outweighs the savings.
The Strategy Explained
A pharmacy benefit carve-out analysis compares the total cost and administrative burden of your current bundled PEO arrangement against a standalone PBM option. This isn’t about automatically carving out—it’s about understanding whether you’re getting competitive value from your PEO’s pharmacy benefits or whether a direct PBM contract would serve you better.
The analysis should include total pharmacy spend, administrative fees, rebate pass-through rates, formulary flexibility, and the cost of managing two separate vendors (PEO for medical, standalone PBM for pharmacy). A thorough cost accounting comparison can help you quantify the true expense of each approach.
Implementation Steps
1. Request detailed pharmacy cost data from your PEO, including total spend, per-employee-per-month (PEPM) costs, generic fill rates, and rebate credits. This is your baseline.
2. Obtain a quote from a standalone PBM (or work with a pharmacy benefits consultant) to model what your costs would look like outside the PEO. Make sure the quote includes all fees, not just ingredient costs.
3. Compare total costs and administrative complexity. If the standalone option saves more than 10-15%, it’s worth serious consideration. If the savings are marginal, the administrative burden of managing two vendors may not be worth it.
Pro Tips
Carving out pharmacy benefits works best for employers with predictable, high-volume pharmacy utilization. If your pharmacy spend is volatile or relatively low, the administrative complexity may outweigh the savings. But if you’re spending six figures annually on pharmacy benefits and your PEO can’t provide transparent pricing, a carve-out analysis is worth the effort.
6. Audit Drug Utilization Patterns Quarterly
The Challenge It Solves
Pharmacy costs don’t just happen—they’re driven by specific utilization patterns, and many of those patterns are invisible unless you’re actively monitoring them. Low generic fill rates, overuse of brand drugs when generics are available, duplicate therapies, and high-cost claimants who aren’t being managed effectively all contribute to unnecessary spend.
Most employers review pharmacy costs annually during renewal, but by then it’s too late to intervene. Quarterly audits allow you to identify problems early and make adjustments before they compound.
The Strategy Explained
Quarterly drug utilization audits focus on four key metrics: generic fill rate (the percentage of prescriptions filled with generic drugs), per-member-per-month (PMPM) pharmacy costs, specialty drug utilization, and high-cost claimant analysis.
Generic fill rates above 90% are generally considered strong performance. If your rate is below 85%, there’s likely waste in the system—employees filling brand prescriptions when generics are available, or your formulary isn’t incentivizing generic use effectively.
High-cost claimant analysis identifies employees with unusually high pharmacy spend. These are often employees on specialty drugs who aren’t enrolled in adherence programs, aren’t using preferred pharmacies, or aren’t being managed through case management. Early intervention can improve outcomes and reduce costs.
Implementation Steps
1. Request quarterly pharmacy utilization reports from your PEO. At minimum, these should include generic fill rate, PMPM costs, specialty drug spend, and a list of top cost drivers (anonymized for privacy).
2. Set performance benchmarks. Track whether your generic fill rate is improving, whether PMPM costs are trending within expected ranges, and whether specialty drug utilization is being actively managed. Developing a PEO cost forecasting model helps you anticipate pharmacy spend trends before they become budget problems.
3. Intervene on outliers. If you identify employees on high-cost specialty drugs who aren’t enrolled in adherence programs, work with your PEO to connect them with case management resources.
Pro Tips
Data without action is just noise. The goal of quarterly audits isn’t just to track numbers—it’s to identify specific interventions that reduce waste and improve outcomes. If your PEO provides reports but doesn’t help you interpret them or take action, you’re only getting half the value.
7. Build Pharmaceutical Cost Guarantees Into Your PEO Contract
The Challenge It Solves
Most PEO contracts include general language about pharmacy benefits, but they don’t hold the PEO accountable for actual performance. You might be promised “competitive pricing” or “access to leading PBMs,” but without specific guarantees, those promises are unenforceable.
If your pharmacy costs spike 20% year-over-year and your PEO shrugs and says “that’s the market,” you have no recourse. You’re stuck with the increase or forced to switch PEOs mid-contract, which is disruptive and expensive.
The Strategy Explained
Pharmaceutical cost guarantees shift accountability to the PEO by building specific performance metrics into your contract. These can include trend caps (maximum allowable year-over-year pharmacy cost increases), rebate minimums (guaranteed rebate pass-through percentages), generic fill rate targets, and performance penalties if the PEO fails to meet agreed-upon benchmarks.
For example, a trend cap might specify that your pharmacy costs can’t increase more than 8% annually unless specialty drug utilization increases by a corresponding amount. A rebate minimum might guarantee that at least 85% of manufacturer rebates are passed through to you as the plan sponsor.
These guarantees don’t eliminate cost increases—pharmacy costs are rising across the industry—but they ensure your PEO has skin in the game and can’t simply pass through unchecked increases without consequence. Understanding how PEOs account for benefits expenses helps you structure guarantees that align with how costs are actually tracked and reported.
Implementation Steps
1. Negotiate specific performance metrics before signing or renewing your PEO contract. Don’t accept vague language like “competitive pricing”—get specific percentages, trend caps, and rebate minimums in writing.
2. Include penalty clauses for underperformance. If your PEO fails to meet the agreed-upon generic fill rate or rebate pass-through percentage, there should be financial consequences—either a credit toward future fees or the ability to terminate the contract without penalty.
3. Review performance against guarantees annually. Your PEO should provide documentation showing whether they met the contractual benchmarks. If they didn’t, hold them accountable.
Pro Tips
Not all PEOs will agree to pharmaceutical cost guarantees, and that tells you something. If a PEO is confident in their pharmacy benefits strategy, they should be willing to stand behind it with contractual commitments. If they resist, it’s worth asking why—and whether you’re better off with a PEO that’s willing to be held accountable.
Putting It All Together
Pharmaceutical cost containment through a PEO isn’t automatic. It requires selecting a PEO with the right PBM structure, negotiating transparency into your contract, and actively monitoring utilization data. The difference between a PEO that treats pharmacy as an afterthought and one that treats it as a strategic lever can easily represent a significant portion of your total pharmacy spend.
Start by auditing your current arrangement against these seven strategies. Can your PEO provide clear answers on rebate pass-through rates? Do they offer formulary customization? Do they have an active specialty drug management program? If the answer is no—or if they can’t provide documentation—that’s a signal to explore alternatives.
The most important question isn’t whether your PEO offers pharmacy benefits. It’s whether they’re structured to actually contain costs, or just administering a plan that passes through whatever the PBM charges.
Before you sign that PEO renewal, make sure you’re not leaving money on the table. Many businesses unknowingly overpay because of bundled fees, hidden administrative markups, and contracts designed to limit flexibility. We give you a clear, side-by-side breakdown of pricing, services, and contract terms—so you can see exactly what you’re paying for and choose the option that truly fits your business.
