If you’re running a 300-employee company and trying to figure out what a PEO should actually cost, you’ve probably noticed something frustrating: every provider gives you a different number, and none of them want to put it in writing until you’ve sat through three sales calls.

You’re stuck in an awkward pricing tier. Too big for the simple small-business rates. Not quite large enough to command enterprise-level attention. And the quotes you’re getting probably range anywhere from $150 to $300 per employee per month—which, when you do the math across 300 people, represents a difference of nearly $540,000 annually.

That’s not a rounding error. That’s real money that either makes sense for your operation or doesn’t.

Here’s what actually drives PEO costs at this headcount, what you should expect to pay, and how to figure out whether the economics work for your specific situation.

Why Your Quotes Look Different Than You Expected

At 300 employees, you’ve crossed into a pricing tier that behaves differently than what smaller companies experience. Volume discounts start appearing, but so do complexity factors that can push costs back up.

Most PEOs structure pricing one of two ways: flat per-employee fees or percentage-of-payroll models. At your scale, the difference matters more than it did when you had 50 employees.

Percentage-of-payroll pricing typically runs 2-4% of gross payroll. If your average employee salary is $60,000, that’s $1,200-$2,400 per employee annually. Sounds reasonable. But if you’re running a tech company or professional services firm where average salaries hit $100,000 or higher, that same percentage suddenly costs $2,000-$4,000 per employee. The PEO isn’t delivering more value because your engineers make more money—you’re just paying more because the pricing model scales with payroll.

Flat per-employee fees provide more predictability. You’ll typically see monthly rates between $150-$250 per employee at 300 headcount, depending on service scope. The number doesn’t fluctuate with raises or bonuses. But here’s the catch: flat fees often exclude certain services that percentage models bundle in, so you need to compare what’s actually included.

Geographic spread changes the equation significantly. If your 300 employees work in three states, administrative complexity stays manageable. If they’re spread across twelve states, you’re dealing with different workers’ comp requirements, varying unemployment insurance systems, and state-specific compliance obligations. That complexity shows up in your pricing.

Benefits participation rates also shift the math. At 300 employees, PEOs start looking at your group’s actual utilization patterns. If 90% of your workforce elects medical coverage, that’s different from 60% participation. Higher participation means more administrative work, more carrier coordination, and potentially different pricing structures.

Industry classification matters more at this scale too. A 300-person manufacturing operation faces different risk profiles than a 300-person marketing agency. Workers’ comp rates, safety compliance requirements, and claims likelihood all factor into what you’ll ultimately pay.

What You’ll Actually Pay: Monthly and Annual Ranges

Let’s cut through the vagueness and talk real numbers.

At 300 employees, monthly per-employee fees typically range from $150 to $250, depending on service scope and your company’s risk profile. That translates to $45,000-$75,000 monthly, or $540,000-$900,000 annually.

That’s a wide range because what’s included varies significantly between providers and pricing tiers.

Basic service packages—payroll processing, tax filing, basic HR support—land toward the lower end. You’re getting operational execution but limited strategic support. Mid-tier packages add benefits administration, compliance assistance, and dedicated account management. Full-service arrangements include risk management consultation, custom policy development, and proactive compliance monitoring.

Workers’ compensation administration is usually included in the base fee, but the actual workers’ comp premium is a pass-through cost that appears separately on your invoice. At 300 employees, this can represent a substantial portion of your total PEO expense, especially in higher-risk industries. A construction company will see materially different workers’ comp costs than a software company, even with identical PEO service fees.

Benefits procurement is where pricing gets murky. Some PEOs bundle benefits administration into their base fee but charge separately for insurance premiums. Others mark up carrier rates as part of their revenue model. You need to understand whether you’re paying a transparent administrative fee or whether margin is embedded in your benefits costs.

Technology access—HRIS platforms, employee self-service portals, reporting dashboards—is typically included at this headcount, but capabilities vary. Some providers offer robust systems comparable to standalone HRIS platforms. Others provide basic portals that handle the minimum.

What usually costs extra: custom compliance projects, specialized training programs, executive compensation consulting, and international employee administration. If you need these services, factor them into your total cost comparison.

Here’s a practical example of how costs can stack up. A 300-employee professional services firm with average salaries around $75,000 might see:

Base PEO fee: $180/employee/month = $54,000/month

Workers’ comp premiums: ~$3,000/month (low-risk classification)

Benefits administration: included in base fee

Health insurance premiums: $450/employee/month average (employer portion) = $135,000/month

Total monthly cost: ~$192,000, or roughly $2.3 million annually

The PEO service fee represents about $650,000 of that total. The question becomes whether that $650,000 delivers enough value compared to alternative approaches.

Cost Drivers That Hit Harder at Your Scale

Certain factors that barely moved the needle when you had 100 employees become significant cost drivers at 300.

Multi-state compliance is the biggest one. If your 300 employees span ten or more states, you’re dealing with materially different administrative complexity. Each state has its own unemployment insurance system, workers’ comp requirements, wage and hour regulations, and leave laws. Some PEOs price this complexity directly into their fees. Others absorb it within their standard rates but may be less competitive if your geographic footprint is particularly complex.

Your claims history and experience modification rate carry real weight now. At 50 employees, your workers’ comp experience mod might not have been fully credible from an actuarial standpoint. At 300 employees, your claims history is statistically meaningful. If you’ve had several significant workers’ comp claims or a pattern of unemployment claims, that will affect your pricing—either through higher experience mods or through risk-adjusted PEO fees.

Benefits utilization patterns become visible at this headcount. When you had 75 employees, one high-cost medical claim didn’t materially affect your group’s profile. At 300 employees, your aggregate claims experience starts influencing renewal rates. PEOs with self-funded or level-funded benefits arrangements will pass this through to you. Even in fully insured scenarios, your group’s utilization affects what you’ll pay at renewal.

Turnover rates matter more. At smaller headcounts, frequent turnover just meant more onboarding work. At 300 employees, high turnover drives up administrative costs, increases unemployment insurance rates, and signals potential workplace issues that create risk exposure. PEOs price this in, either explicitly or through risk-adjusted fees.

The Build vs. Buy Calculation You Can Actually Run Now

Here’s where things get interesting. At 300 employees, building internal HR infrastructure becomes financially viable.

You could hire a VP of HR for $150,000-$180,000, an HR generalist for $60,000-$75,000, and a benefits coordinator for $50,000-$65,000. Add payroll software ($15,000-$30,000 annually), a benefits broker (typically 3-6% of benefits premiums), and an HRIS platform ($10,000-$25,000 annually). Total annual cost: roughly $300,000-$400,000 in direct expenses.

That’s materially less than most full-service PEO arrangements at this scale.

So why do companies still use PEOs at 300 employees?

Benefits purchasing power remains legitimate. Even at 300 employees, you’re unlikely to command the same carrier rates that a PEO with 10,000+ employees across multiple clients can negotiate. The difference in medical premiums alone can be $50-$100 per employee per month. Across 300 employees, that’s $180,000-$360,000 annually—enough to offset a significant portion of PEO fees.

Compliance bandwidth is the other persistent advantage. Employment law changes constantly. Tracking updates across multiple states, understanding how new regulations apply to your specific situation, and implementing compliant policies requires dedicated attention. A good PEO provides this as part of their service. Building it internally means your HR team needs both the expertise and the capacity to stay current.

Workers’ comp bundling can deliver value if your industry carries higher risk. PEOs spread risk across their entire client base, which can result in better rates than you’d get independently, especially if your claims history isn’t perfect.

Where internal teams win: control, customization, and long-term cost trajectory. You can build HR policies that fit your culture exactly. You’re not constrained by a PEO’s standard offerings or technology limitations. And your costs don’t automatically increase as your headcount grows—a three-person HR team can often support 300-500 employees without proportional cost increases.

The right answer depends on your specific situation. If you’re growing quickly, operate in a complex regulatory environment, or lack internal HR expertise, a PEO might deliver more value than the cost suggests. If you have stable operations, concentrated geography, and strong internal leadership, building your own infrastructure probably makes more financial sense. Running a thorough cost benefit analysis will help clarify which path works for your company.

Negotiating Leverage You Actually Have

At 300 employees, you’re not a small account anymore. PEOs want your business, and you have real leverage if you use it strategically.

Start by getting at least three competitive quotes. Not just proposals—actual pricing breakdowns with transparent fee structures. PEOs know you’re comparing options, and the mere existence of competition typically yields better initial offers.

Push on rate locks. Standard contracts often include language allowing annual rate increases based on “market conditions” or “cost of services.” At your scale, you can negotiate multi-year rate locks or caps on annual increases. A 3% annual cap might not sound significant, but over a three-year contract, it prevents your costs from escalating unpredictably.

Exit provisions matter more than you think. Many PEO contracts include restrictive termination clauses—60-90 day notice periods, end-of-plan-year termination windows, or penalties for early exit. At 300 employees, you should be able to negotiate more favorable terms: 30-day notice, quarterly termination windows, and no financial penalties beyond paying for services rendered. Understanding how to compare PEO contracts gives you the knowledge to push back on unfavorable terms.

Service level guarantees should be explicit. What response time can you expect for HR questions? How quickly will payroll issues be resolved? What happens if they miss a compliance deadline? Get commitments in writing, ideally with remedies if they fail to meet agreed standards.

Questions that reveal true cost structure:

“What’s your average annual rate increase for accounts our size?” If they won’t answer or give vague responses, that’s a red flag.

“How do you handle benefits renewals, and what’s your markup on carrier rates?” Transparent PEOs will explain their compensation model clearly. Evasive answers suggest hidden margin.

“What triggers price increases outside of renewal?” Headcount growth, geographic expansion, and claims experience all might affect pricing. Understand the variables before you sign.

“Can you show me renewal history for similar accounts?” Some PEOs provide stable, predictable pricing. Others use low initial rates to win business, then increase significantly at renewal. Track record matters.

When the Math Stops Working

At 300 employees, you’re approaching the threshold where traditional PEO arrangements often stop making economic sense.

If your total PEO costs—including all fees, not just the base service charge—exceed 8-10% of your gross payroll, scrutinize what you’re actually getting. That’s a significant expense that needs to deliver proportional value. Watch out for hidden fees that inflate your total spend beyond the quoted rates.

Your growth trajectory matters. If you’re heading toward 500+ employees within the next two years, start planning your exit now. The economics shift further as you scale, and transitioning off a PEO takes time. You’ll need to establish independent benefits arrangements, implement your own payroll and HR systems, and potentially hire internal staff. Starting that process before you’re forced to makes the transition smoother.

Watch for signs you’ve outgrown your PEO’s capabilities. If you’re constantly requesting services they don’t offer, working around limitations in their technology, or finding that their standard policies don’t fit your business, you’re paying for constraints rather than solutions.

Alternative structures exist between full PEO and completely internal HR. Administrative Services Organization (ASO) arrangements provide many PEO benefits—benefits administration, payroll processing, compliance support—without the co-employment relationship. You maintain more control and often pay lower fees, though you lose some of the purchasing power advantages.

Unbundled services let you keep the pieces that deliver value while handling the rest internally. Maybe you use a PEO just for benefits administration and workers’ comp, while managing payroll and HR internally. This approach requires more coordination but can be significantly less expensive.

Hybrid approaches work for some companies. Use a PEO for a subset of employees—perhaps those in complex states or high-risk roles—while managing the rest internally. This isn’t always possible depending on PEO minimum requirements, but it’s worth exploring if your workforce has distinct segments.

Making the Decision That Actually Fits Your Business

At 300 employees, you’re past the point where a PEO is an obvious default choice. The economics need to work for your specific situation, not just in theory.

Get at least three detailed quotes. Not ballpark estimates—actual pricing breakdowns showing base fees, included services, pass-through costs, and what triggers additional charges. Compare them against the cost of building internal infrastructure, including realistic salary expectations, benefits, systems, and broker fees.

Model both scenarios over three years. PEO costs will likely increase annually. Internal costs will too, but potentially at a different rate. Which trajectory makes more sense given your growth plans and operational priorities?

Talk to current clients at similar headcounts. Ask about renewal pricing, service quality, and whether they’d make the same choice again. References provided by the PEO will be positive, but how they describe their experience tells you a lot about what to expect.

Before you renew your PEO agreement, compare your options. Most businesses overpay due to bundled fees and unclear administrative markups. We break down pricing, services, and contract structures so you can make a smarter decision.

The right PEO relationship can deliver real value at 300 employees—but only if the economics actually work for your operation, your industry, and your growth trajectory. Don’t renew automatically. Run the numbers, understand your alternatives, and make sure you’re getting what you’re paying for.