ADP TotalSource vs. Paychex PEO
These are the two payroll-led PEOs, and both are quote-only with no published pricing. Paychex's distinctive advantage is that it sells an ASO alongside its PEO, so you can step down from co-employment without changing vendors. ADP's is the depth of its surrounding technology stack. Both default to annual contracts with auto-renewal, so read the notice and termination terms before signing.
ADP TotalSource
- Co-employment PEO from the largest payroll platform — payroll, HR, benefits, and compliance under one arrangement
- Third-party trackers commonly report pricing as a percentage of total payroll or a per-employee fee, but ADP publishes neither; treat all reported ranges as estimates
- Reported add-on and implementation costs (technology modules, reporting, year-end filings) are a recurring theme in third-party reviews — ask for the complete fee schedule, not the base quote
- ADP's own comparison pages claim integrated PEO platform, data benchmarking, and a Legal Defense Benefit relative to Paychex; these are vendor claims about a competitor and should be verified in the proposal
- Contracts are commonly reported as annual with auto-renewal and 60–90 days' written notice to exit
- Best fit if you already run ADP payroll and want one vendor across payroll and co-employment
Paychex PEO
- Co-employment PEO sold alongside the better-known Paychex payroll platform, plus a named support structure: Client Advocate, HR Business Partner, Payroll Specialist, and Safety Specialist
- Paychex HR Solutions is offered as both an ASO and a PEO — the ASO keeps you as sole employer, which gives you a path to step down from co-employment without switching vendors
- Published figure from Paychex's 10-K (fiscal year ended May 31, 2026): approximately 2.6 million worksite employees supported across its HR outsourcing solutions, with more than 650 HR business professionals
- Quote-only pricing; some clients are reported as quoted per-employee and others as a percentage of payroll, so insist on knowing which structure you are being offered
- Third-party reviews commonly report heavier upfront discounting followed by renewal increases — model years two and three, not year one
- Best fit for existing Paychex payroll customers weighing an upgrade to PEO, and for companies under about 50 employees
How should you make the decision?
Start with the work your company needs performed, the decisions that require internal ownership, the amount of day-to-day capacity required, and the risks of changing models. Then ask providers to map their scope against that operating picture.
A model is not a quality guarantee. Service teams, implementation, systems, pricing, and contract terms differ materially within every category.
Sources and caveats
Neither ADP nor Paychex publishes PEO pricing. Every dollar figure in third-party comparisons of these two is an estimate, and the published estimates contradict each other — reported ranges for ADP TotalSource span roughly $150 to $350 per employee per month, and Paychex PEO roughly $125 to $250. HRPair deliberately does not restate these as fact. The only reliable comparison is two quotes against your own census.
The Paychex ASO/PEO pairing and the worksite-employee count come from Paychex's own SEC filings. The capability claims comparing the two come from ADP's own comparison pages and are vendor marketing.
Both vendors' contracts are commonly reported as annual with auto-renewal. Early termination fees are a real risk in this category — in some reported cases equal to several months of service fees. Get the notice period and termination language in writing before you sign.