Most PEO sales pitches include impressive savings numbers. The problem? Those projections often use assumptions that don’t match your actual situation—your industry, your claims history, your current vendor costs, your growth trajectory. Building your own savings projection model puts you in control of the math. You can stress-test different scenarios, compare providers apples-to-apples, and make a decision based on your numbers rather than theirs.
This guide walks you through creating a practical PEO savings projection model from scratch. We’re not talking about a quick back-of-napkin calculation—this is a structured approach that accounts for the major cost categories where PEOs typically deliver (or fail to deliver) value. By the end, you’ll have a working model you can use to evaluate any PEO proposal and project realistic savings over a 1-3 year horizon.
Step 1: Gather Your Current HR Cost Baseline
You can’t measure savings without knowing what you’re currently spending. Start by identifying the five core cost categories that matter most: benefits premiums, payroll processing, workers’ comp, HR administration time, and compliance or legal exposure.
Pull actual numbers from the past 12 months. Not estimates. Not budgets. Actual invoices, actual payroll reports, actual premiums paid. Most businesses underestimate their true HR costs because they focus only on the obvious line items and miss the hidden expenses.
Here’s what that looks like in practice. Your benefits premiums are straightforward—pull them from your broker or carrier statements. Payroll processing costs should include your software subscription plus any per-check fees. Workers’ comp is on your insurance renewal documents. But then you hit the less obvious costs.
How much time does your office manager or HR person spend answering benefits questions during open enrollment? How many hours go into fixing payroll errors each month? What about the time spent managing unemployment claims, researching compliance requirements for a new state, or coordinating with your workers’ comp carrier after an injury?
Document these hidden costs systematically. Track one typical month and multiply it out. If your HR coordinator spends six hours per month on benefits administration that wouldn’t exist without employees, that’s 72 hours annually. At a fully-loaded rate of $35 per hour, that’s $2,520 in labor costs tied directly to benefits management.
Create a simple spreadsheet structure to organize this baseline data. One column for each cost category. One row for each month over the past year. This gives you both annual totals and visibility into seasonal patterns—benefits costs spike during renewal months, workers’ comp gets trued up at year-end, payroll processing might increase if you hire seasonally.
The goal here isn’t perfection. It’s establishing a realistic baseline that accounts for both hard costs (invoices you can see) and soft costs (time you’re currently spending). Most businesses discover their true HR costs are 15-25% higher than they initially thought once they factor in administrative time.
Step 2: Quantify Your Soft Costs and Risk Exposure
Soft costs are where most business owners get vague. “My office manager handles HR stuff” doesn’t translate into a number you can compare against a PEO quote. You need to be more precise.
Start with HR administrative time burden. How many hours per month does someone in your organization spend on compliance research? Answering employee benefits questions? Fixing payroll issues? Managing unemployment claims? Coordinating workers’ comp paperwork after an injury?
Track this for one representative month. Don’t guess. Actually log the time. You’ll probably find it’s more than you thought. A typical small business with 25-50 employees often has someone spending 20-30 hours per month on HR administration that wouldn’t exist without employees.
Now assign realistic dollar values using fully-loaded labor rates. If your office manager makes $50,000 annually, their fully-loaded cost (including payroll taxes, benefits, and overhead) is closer to $65,000-70,000. That works out to roughly $35 per hour. Thirty hours per month at $35 per hour equals $1,050 in monthly labor costs tied to HR administration.
Next comes compliance risk exposure. This is harder to quantify because you’re estimating the cost of things that haven’t happened yet. But the risk is real.
If you’re running multi-state payroll, what’s the potential penalty for misclassifying an employee in a state with strict wage and hour laws? What’s your exposure if you mess up ACA reporting and trigger IRS penalties? What could an OSHA violation cost you if someone gets injured and you haven’t maintained proper documentation?
You don’t need to become a compliance expert here. The point is to acknowledge that these risks exist and assign a rough annual cost. Even a conservative estimate—say $5,000 annually for potential compliance exposure—gives you a number to work with when evaluating whether a PEO’s HR compliance support justifies its cost.
Here’s the critical distinction: identify which soft costs are genuinely reducible versus which will persist regardless of whether you use a PEO. A PEO can handle benefits administration and compliance research. It can’t eliminate the need for someone in your organization to manage the PEO relationship, answer basic employee questions, or make strategic HR decisions.
Most PEO pitches overestimate time savings by assuming you’ll eliminate an entire HR role. That rarely happens. What actually happens is your HR person shifts from tactical execution to strategic oversight. That’s valuable, but it’s not the same as eliminating the cost entirely.
Step 3: Map PEO Pricing Structures to Your Model
PEO pricing comes in two main flavors: per-employee-per-month (PEPM) or percentage of payroll. Each has implications for how costs scale as your business grows.
PEPM pricing is straightforward. The PEO charges a flat fee per employee per month—typically ranging from $80 to $250 depending on services included and your company size. If you have 30 employees and the rate is $150 PEPM, you’re paying $4,500 monthly regardless of how much those employees earn.
Percentage of payroll pricing ties your PEO cost directly to total payroll. A rate of 3% on $2 million in annual payroll equals $60,000 annually. This model can work better for businesses with high-wage employees, since the per-employee cost effectively increases with compensation levels.
Request itemized quotes that break out admin fees, benefits costs, and workers’ comp separately. Some PEOs bundle everything into one blended rate. Others unbundle so you can see exactly what you’re paying for each component. Unbundled pricing gives you more transparency and makes it easier to compare providers apples-to-apples.
Build comparison columns for at least two to three PEO providers using identical assumptions. Same headcount. Same payroll total. Same benefits plan design. This is the only way to see meaningful differences in pricing structure.
Watch for bundled versus unbundled pricing games. A PEO might quote you a low PEPM rate but then add significant markups to benefits premiums. Another might quote a higher PEPM but pass through benefits at actual cost. You can’t compare these directly without breaking down the components.
Here’s what this looks like in your model. Create one column for your current costs. Create additional columns for each PEO you’re evaluating. For each column, break out the monthly cost by category: admin fees, health insurance, workers’ comp, payroll processing, and any other line items the PEO includes.
This structure lets you see where each provider delivers value and where they don’t. You might find that Provider A has lower admin fees but higher benefits costs. Provider B might have better workers’ comp rates but charges more for payroll processing. The total cost matters, but understanding the component costs helps you negotiate and make tradeoffs.
Step 4: Build Savings Projections by Cost Category
Now you’re ready to calculate actual savings by comparing your current costs to each PEO’s pricing for the same services. Work through this category by category.
Start with health insurance. Compare your current per-employee premium to the PEO’s group rates. But don’t just compare the dollar amounts—you need to factor in plan design differences. If your current plan has a $1,000 deductible and the PEO’s plan has a $2,500 deductible, the premium might be lower but the value isn’t equivalent.
Ask for detailed plan summaries. Look at deductibles, copays, coinsurance, out-of-pocket maximums, and network coverage. A plan that costs $50 less per month but has a $1,500 higher deductible isn’t actually saving you money if your employees use healthcare regularly.
For workers’ compensation, calculate potential savings from the PEO’s experience mod rates versus your standalone rate. The PEO’s mod is based on their entire client pool, which is usually more favorable than a small company’s individual mod—especially if you’ve had recent claims. Understanding how to track workers’ comp accounting through your PEO helps you verify these savings are actually materializing.
But here’s the catch: not all businesses qualify for the PEO’s best rates. If your industry classification code is high-risk or you have a poor claims history, the PEO might place you in a higher-cost tier. Ask specifically what rate tier you’d qualify for based on your claims history and industry.
Payroll and HR admin savings come from comparing your current processing costs plus administrative time to the PEO’s bundled offering. If you’re currently paying $200 monthly for payroll software plus spending 20 hours per month on HR administration at $35 per hour, your current cost is $900 monthly. If the PEO charges $150 PEPM for 30 employees ($4,500 monthly) but eliminates both the software cost and most of that administrative time, you need to net those savings against the PEO fee.
Create formulas in your spreadsheet that calculate net savings for each category. The formula is simple: PEO cost minus current cost equals net savings (or net increase). Do this for every cost category, then sum them up to see your total monthly and annual savings projection.
Don’t forget to account for costs that don’t change. Your state unemployment tax doesn’t go away with a PEO. Neither does your basic accounting overhead or the time spent on strategic HR decisions. Only include savings for costs that genuinely transfer to the PEO.
Step 5: Stress-Test Your Model with Multiple Scenarios
A single-point estimate is useless. You need to understand the range of possible outcomes based on how key variables might change over time.
Build three scenarios: conservative, moderate, and optimistic. Your moderate scenario uses your best estimates for each variable—the numbers you actually expect. The conservative scenario assumes things don’t go as well as planned. The optimistic scenario assumes everything breaks your way.
Start with headcount growth. If you’re planning to grow from 30 to 40 employees over the next two years, model what happens to your costs under each scenario. PEO pricing often improves with scale, but your per-employee benefits costs might increase if you’re adding older employees or employees with higher healthcare utilization.
Adjust benefits utilization assumptions. What happens if your claims experience worsens and your health insurance premiums increase 15% instead of the expected 8%? Does the PEO’s pooled rate still deliver savings, or does it increase at the same rate as your standalone plan would have?
Model the impact of rate increases over two to three years. PEO pricing isn’t static. Admin fees typically increase 3-5% annually. Benefits costs follow market trends. Workers’ comp rates adjust based on claims experience. Build these increases into your projections so you’re not surprised at renewal time.
Here’s a scenario structure that works: In your conservative case, assume headcount grows slower than planned, benefits costs increase faster than expected, and PEO admin fees increase at the high end of the typical range. In your moderate case, use your best estimates for all variables. In your optimistic case, assume headcount grows as planned, benefits costs increase at market rates, and you negotiate favorable pricing.
Identify break-even points. At what headcount does the PEO stop making financial sense? If you’re currently at 30 employees and the PEO delivers $2,000 monthly savings, but you’re planning to grow to 100 employees where you could negotiate similar benefits rates independently, when does that crossover happen?
This scenario analysis shows you not just whether a PEO makes sense today, but whether it will continue making sense as your business evolves. That matters because PEO contracts often include termination fees or require annual commitments.
Step 6: Validate Assumptions Against Real Provider Data
Your model is only as good as the assumptions you’ve built into it. Before you commit to a decision, validate those assumptions against real-world data from the PEO providers you’re considering.
Ask PEO providers for client references in your industry and size range. Talk to those references specifically about whether the savings they were promised materialized. Were the benefits rates accurate? Did admin fees increase more than expected? How did workers’ comp costs trend over time?
Request historical rate increase data for the past three to five years. A PEO that claims stable pricing should be able to show you actual renewal rate increases for existing clients. If they can’t or won’t provide this data, that’s a red flag.
Compare your model’s projections against the PEO’s own ROI estimates. If your conservative scenario shows $15,000 annual savings but the PEO is claiming $40,000 in savings, dig into where the gap comes from. Are they including soft cost savings you don’t think are realistic? Are they using benefits rate assumptions that don’t match your claims history? Understanding how to calculate whether a PEO actually saves you money helps you spot inflated projections.
Significant gaps warrant explanation. Either your assumptions are too conservative, or their projections are too optimistic. Walk through the math together and document where you agree and where you don’t.
Document which assumptions in your model are verified versus estimated. Maybe the benefits rates are confirmed based on your census data and claims history. But the time savings estimate is still a guess based on how much HR administration you think will transfer to the PEO. Mark those clearly so you know which variables to watch closely once you’re actually working with the provider.
This validation step also gives you negotiating leverage. If your model shows that the PEO’s pricing only delivers meaningful savings under optimistic assumptions, you can negotiate for better rates or push back on contract terms that lock you in before you’ve validated the savings.
Making Your Model Work for You
A solid PEO savings projection model isn’t about predicting exact dollar amounts. It’s about understanding the range of outcomes and the variables that matter most for your business. Your model should answer three questions: What’s the realistic best case? What’s the floor if things don’t go as planned? And what would need to change for a PEO to stop making sense?
The businesses that get the most value from PEOs are the ones who understand their own numbers well enough to hold providers accountable. If your PEO promised $30,000 in annual savings but your actual costs are tracking higher, you have the data to push back. If your headcount is growing faster than expected and you’re hitting pricing tiers where the PEO’s rates are less competitive, you know when to renegotiate or consider alternatives.
Revisit your model annually. Update it with actual costs from the past year. Adjust your assumptions based on what actually happened versus what you projected. This turns your model from a one-time decision tool into an ongoing management tool that helps you optimize your HR spend over time.
Use your model as a negotiating tool when renewal time comes around. PEOs know that most clients don’t have detailed cost models and don’t comparison shop at renewal. If you can show them exactly where their pricing has increased relative to your projections and what competitive alternatives look like, you’re in a much stronger position to negotiate favorable terms.
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. Don’t auto-renew. Make an informed, confident decision.
