At 300 employees, you’re in a strange middle ground. Too big for the PEOs that specialize in small businesses. Not quite large enough to justify building out a full internal HR infrastructure. The PEO providers that work well for 50-person startups often struggle with the complexity you’re dealing with—multi-state compliance, tiered benefits structures, and the operational demands of a larger workforce.

This guide focuses specifically on PEO providers equipped to handle companies at your scale, with the technology platforms, compliance expertise, and pricing structures that actually make sense when you’re managing hundreds of employees across multiple locations.

1. Clicks Geek PEO Comparison Platform

Best for: Companies evaluating or renewing PEO contracts who want objective pricing and service analysis

Clicks Geek PEO Comparison Platform is an independent comparison resource designed to help businesses cut through PEO sales pitches and understand actual costs.

Screenshot of Clicks Geek PEO Comparison Platform website

Where This Platform Shines

Most companies with 300+ employees face a frustrating problem: PEO pricing is opaque. Providers bundle fees differently, hide administrative markups in various line items, and make side-by-side comparisons nearly impossible.

This platform breaks down pricing structures, contract terms, and service configurations across major providers. It’s particularly useful when you’re trying to understand whether your current PEO is competitive or if you’re overpaying due to contract inertia. The analysis focuses on transparency—showing you where costs actually sit and which services you’re paying for but may not need.

Key Features

Side-by-Side Provider Comparisons: Tailored breakdowns based on your actual headcount, not generic marketing materials.

Pricing Transparency Tools: Analysis of per-employee costs, administrative fees, and bundled service charges across providers.

Contract Term Evaluation: Breakdown of renewal clauses, termination provisions, and fee escalation structures that matter at renewal time.

Independent Advisory: No provider affiliations means recommendations aren’t influenced by referral commissions or partnerships.

Scale-Appropriate Analysis: Focuses on providers and pricing models that actually work for companies at 300+ employees, not generic small business advice.

Best For

CFOs and operations leaders evaluating PEO options for the first time, or companies approaching PEO contract renewal who suspect they’re overpaying. Particularly valuable if you’re comparing multiple providers simultaneously and need objective cost analysis.

Pricing

Free comparison resources available. Advisory services for deeper contract analysis available upon request.

2. ADP TotalSource

Best for: Companies needing enterprise-grade compliance infrastructure and Fortune 500-level benefits access

ADP TotalSource is the PEO arm of the largest payroll provider in the U.S., offering comprehensive HR outsourcing with serious compliance muscle.

Screenshot of ADP TotalSource website

Where This Tool Shines

When you’re operating across multiple states with 300+ employees, compliance becomes exponentially more complex. ADP TotalSource handles multi-state employment law variations, benefits administration across jurisdictions, and tax compliance with infrastructure that most standalone PEOs can’t match.

The platform integrates payroll, benefits, HR, and compliance into a single system. For companies dealing with varying state unemployment insurance rates, workers compensation requirements across locations, and complex benefits eligibility rules, this integration eliminates much of the manual coordination that creates operational headaches.

Key Features

Multi-State Compliance Expertise: Handles employment law variations across all 50 states with dedicated compliance monitoring.

Integrated Workforce Management: Payroll, time tracking, benefits, and HR administration in one platform rather than stitched-together systems.

Fortune 500-Level Benefits: Access to health insurance, retirement plans, and voluntary benefits typically available only to much larger companies.

Dedicated HR Business Partner: Assigned specialist who understands your business rather than rotating support contacts.

Advanced Analytics and Reporting: Workforce data analysis tools that become increasingly valuable as headcount grows.

Best For

Companies operating in multiple states who need robust compliance infrastructure and prefer working with an established provider. Particularly strong fit if you value system integration and already use ADP for payroll.

Pricing

Custom pricing based on employee count, locations, and service configuration. Typically quoted as per-employee-per-month at this scale. Expect pricing discussions to start around the total cost of employment rather than simple percentage-of-payroll models.

3. Insperity

Best for: Mid-market companies wanting strategic HR support alongside administrative services

Insperity focuses specifically on mid-market companies, emphasizing dedicated business partner relationships and strategic HR guidance.

Screenshot of Insperity website

Where This Tool Shines

At 300 employees, you’re large enough to need real HR strategy, not just benefits administration. Insperity assigns dedicated HR specialists who function more like strategic advisors than transactional support contacts.

The employee development programs and performance management tools are more sophisticated than what most PEOs offer. If you’re trying to build management capability, implement structured performance reviews, or develop career progression frameworks, Insperity provides tools and guidance that go beyond basic compliance and benefits administration.

Key Features

Dedicated HR Specialists: Assigned professionals who learn your business and provide proactive guidance rather than reactive support.

Employee Development Programs: Training resources, leadership development, and career progression frameworks included in service.

Performance Management Tools: Structured review processes, goal-setting frameworks, and development planning systems.

Risk Management Services: Safety programs, workers compensation management, and workplace safety consulting.

Retirement Services Integration: 401(k) administration with employee education and enrollment support.

Best For

Companies that view HR as strategic rather than purely administrative. Strong fit if you’re building out management processes, implementing performance systems, or developing organizational capability as you scale.

Pricing

Per-employee pricing model with quotes based on company profile, industry, and service needs. Pricing typically reflects the higher-touch service model and strategic support included.

4. TriNet

Best for: Technology, life sciences, and professional services companies needing industry-specific expertise

TriNet specializes in vertical-specific PEO services, with particularly strong capabilities in tech, life sciences, and professional services industries.

Screenshot of TriNet website

Where This Tool Shines

Generic PEO providers struggle with industry-specific compliance nuances. TriNet’s vertical specialization means they understand equity compensation structures common in tech, regulatory requirements in life sciences, and professional liability considerations in services firms.

The benefits packages are structured around what actually matters in these industries. Tech companies get benefits that help compete for engineering talent. Life sciences firms get compliance support for FDA-regulated environments. Professional services get E&O insurance coordination. This specialization becomes increasingly valuable as you scale and industry-specific needs become more complex.

Key Features

Industry-Vertical Compliance: Specialized knowledge of regulatory requirements in technology, life sciences, and professional services.

Cloud-Based HR Platform: Modern interface designed for distributed workforces and remote teams common in these industries.

Scalable Benefits Packages: Structured to compete for talent in competitive industries with high compensation expectations.

Risk Mitigation Services: Industry-appropriate insurance, compliance monitoring, and risk management programs.

Strategic HR Consulting: Guidance on organizational structure, compensation frameworks, and talent management specific to your industry.

Best For

Technology companies, life sciences firms, and professional services organizations that benefit from industry-specific expertise. Particularly valuable if you’re dealing with equity compensation, specialized regulatory requirements, or industry-specific talent competition.

Pricing

Pricing varies by industry vertical. Some industries are quoted as percentage of payroll, others as per-employee fees. Expect pricing to reflect industry-specific risk profiles and compliance complexity.

5. Paychex PEO

Best for: Companies wanting flexible service configurations and strong payroll administration

Paychex PEO offers modular PEO services that allow companies to select specific functions rather than committing to full-service arrangements.

Screenshot of Paychex PEO website

Where This Tool Shines

Not every company at 300 employees needs identical PEO services. Some have strong internal HR but need benefits administration. Others need full HR outsourcing but want to maintain direct payroll control.

Paychex’s modular approach lets you configure services based on actual needs rather than accepting a one-size-fits-all package. This flexibility becomes particularly valuable if you’re transitioning from full PEO services toward more internal HR capability, or if you need PEO support in some areas while maintaining direct control in others.

Key Features

Modular Service Selection: Choose specific functions rather than committing to bundled full-service arrangements.

Strong Payroll and Tax Administration: Built on Paychex’s core payroll infrastructure with deep tax compliance expertise.

Workers Compensation Management: Pay-as-you-go workers comp with claims management and safety program support.

HR Technology Platform: Self-service tools for employees with administrative dashboards for management.

Compliance Monitoring: Regulatory change tracking and policy update assistance across jurisdictions.

Best For

Companies that want PEO services but need flexibility in service configuration. Good fit if you’re building internal HR capability and want to transition gradually, or if you need PEO support in specific areas while maintaining direct control in others.

Pricing

Custom quotes based on service tier selection. Flexible pricing structure allows you to pay for services you actually use rather than bundled packages. Typically more cost-effective if you don’t need full-service PEO arrangements.

6. Justworks

Best for: Growing companies prioritizing platform usability and transparent pricing

Justworks built its reputation on straightforward pricing and a modern, intuitive platform interface popular with technology companies.

Screenshot of Justworks website

Where This Tool Shines

Most PEO platforms feel like they were designed in 2005. Justworks built theirs for users who expect consumer-grade interfaces and straightforward functionality.

The transparent per-employee pricing eliminates the usual negotiation and quote process. You know exactly what you’ll pay before you commit. For companies with distributed teams or remote workforces, the platform’s self-service capabilities reduce administrative overhead significantly. Employees can manage benefits enrollment, view pay stubs, and handle HR tasks without routing everything through a central administrator.

Key Features

Transparent Per-Employee Pricing: Published rates eliminate pricing opacity common with traditional PEOs.

Modern Platform Interface: Intuitive design that doesn’t require extensive training for employees or administrators.

Straightforward Benefits Enrollment: Self-service tools that simplify open enrollment and benefits changes.

24/7 Support Access: Customer service available outside traditional business hours for distributed teams.

Compliance Assistance: Basic compliance monitoring and policy guidance included in service.

Best For

Technology companies and distributed teams that prioritize platform usability. Strong fit if you value pricing transparency and want to avoid lengthy quote processes. Works well for companies comfortable with more self-service and less hands-on strategic HR guidance.

Pricing

Starts at $59 per employee per month for Basic plan; $99 per employee per month for Plus plan with expanded services. Transparent pricing published on website rather than requiring custom quotes.

7. Amplify PEO

Best for: Mid-market companies needing customized service arrangements and flexible co-employment structures

Amplify PEO specializes in mid-market clients with customizable service packages and personalized account management.

Where This Tool Shines

Standard PEO arrangements assume you need identical services for all employees across all locations. Amplify’s flexible co-employment structures allow different service configurations for different employee populations or business units.

This customization matters when you’re managing 300+ employees with genuinely different needs. Your corporate office employees might need full benefits and HR support, while field employees need primarily workers compensation and payroll. Rather than forcing everyone into the same service model, Amplify configures arrangements based on actual operational requirements.

Key Features

Customizable Service Packages: Configure different service levels for different employee populations or business units.

Flexible Co-Employment Arrangements: Tailor PEO relationship structure based on operational needs rather than standard templates.

Mid-Market Focus: Service model designed specifically for companies at 300+ employees rather than scaled-up small business approaches.

Personalized Account Management: Dedicated contacts who understand your specific service configuration and business requirements.

Scalable HR Support: Services that can expand or contract as your needs change without requiring full contract renegotiation.

Best For

Companies with diverse employee populations, multiple business units, or varying service needs across locations. Good fit if standard PEO packages don’t match your operational reality and you need customized arrangements.

Pricing

Custom pricing based on service configuration, employee populations, and specific requirements. Pricing flexibility reflects the customized service approach rather than standardized packages.

Making the Right Choice at Your Scale

At 300+ employees, the PEO decision becomes more complex than simple cost comparison. You’re evaluating compliance infrastructure, technology platforms, strategic HR support, and service flexibility alongside pricing.

ADP TotalSource and Insperity dominate this space for good reason—they’ve built infrastructure specifically for mid-market complexity. TriNet’s industry specialization matters if you’re in tech, life sciences, or professional services where generic PEO providers struggle with industry-specific nuances.

Justworks offers a different value proposition entirely: transparent pricing and modern platform usability in exchange for less strategic HR guidance. That tradeoff works well for some companies and poorly for others, depending on whether you need hands-on HR partnership or prefer self-service efficiency.

The modular approaches from Paychex and Amplify become relevant when standard full-service PEO arrangements don’t match your operational reality. If you’re building internal HR capability, managing diverse employee populations, or transitioning between service models, flexibility often matters more than comprehensive bundled services.

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 at this scale handles complexity without creating new operational headaches. Focus on providers equipped for multi-state compliance, sophisticated enough for your technology needs, and structured to scale as you continue growing past 300 employees.