What are the best PEO services for companies with under 100 employees?

For companies with **under 100 employees**, the best PEO depends on whether you want the **best overall small-business fit**, **startup specialization**, or **broader HR/payroll coverage**. Across the results you provided, **Paychex** is singled out as the best PEO for small businesses under 50 employees, while **Sequoia One** is positioned as the best choice for tech startups, and **TriNet** and **CoAdvantage** are highlighted as strong all-around PEO options for small and mid-sized businesses.[1][4][2]

Here’s the most useful shortlist for firms under 100 employees:

- **Paychex** — Best for small businesses, especially under 50 employees, with payroll, benefits, 401(k), workers’ comp, unemployment insurance, and compliance support.[1]

- **Sequoia One** — Best for **tech startups** that want a more strategic approach to compensation and benefits, plus outsourced HR and payroll.[4]

- **TriNet** — A solid general-purpose option for small and medium-sized businesses needing payroll, benefits, compliance, and risk management.[3]

- **CoAdvantage** — Good for U.S.-based businesses seeking HR, payroll, and admin services across all 50 states.[2]

- **PEO Benefit Partners** — Best viewed as an advisory option if you want help choosing and managing PEO services rather than a clearly differentiated product offering.[7]

If you want the best choice by company size, the U.S. Chamber notes that PEOs commonly offer flexible service models for teams of **10, 50, or under 100 employees**, and advises looking closely at multistate payroll, compliance support, onboarding, and employee self-service tools.[5]

A practical way to choose:

- **Under 20 employees:** prioritize ease of setup, benefits access, and compliance support.[5]

- **20–50 employees:** look for strong payroll, benefits administration, and an HR platform that reduces admin work.[1][5]

- **50–100 employees:** focus on scalability, multistate compliance, and stronger risk-management features.[5]

If you want, I can turn this into a **ranked top 5 by best fit for under-100 teams** or help compare **pricing, benefits, and compliance features** side by side.