ADP TotalSource vs Insperity

ADP TotalSource and Insperity are both IRS certified and ESAC accredited PEOs, and neither publishes pricing. ADP states TotalSource serves businesses with 5 to more than 1,000 employees and runs inside ADP's own payroll infrastructure. Insperity organizes around a dedicated HR specialist model and now sells a Workday powered tier called Insperity HRScale.

Written for US employers with 20 to 500 employees. Every claim below is sourced to the vendor's own site, the IRS, ESAC or federal law, and the sources are linked. Where something is not published, this page says so rather than guessing.

Side by side

Where ADP TotalSource wins

Certified entity depth. This sounds like trivia and is not. CPEO status attaches to specific legal entities, not to a brand. Eighteen separate ADP TotalSource entities sit on the IRS active list, which makes it very likely that whichever entity ends up on your service agreement is itself certified. On PEOs that appear on the IRS list with only one or two certified entities, that is not a safe assumption. Ask for the contracting entity name in writing and check it against the IRS list yourself.

Payroll and tax infrastructure that already exists at scale. ADP has been filing employment taxes since long before the PEO industry existed. For a company with employees in many states, a lot of what goes wrong in a PEO relationship is multi state tax registration and filing, and that is ADP's oldest competency rather than a bolt on.

A published size range. ADP states 5 to more than 1,000 employees, an unusually wide published band. ADP also describes TotalSource as the nation's largest IRS certified and ESAC accredited PEO. Treat "largest" as a vendor claim, because neither the IRS list nor the ESAC directory ranks PEOs by size, though the certification and accreditation parts check out at the source.

Where Insperity wins

The service model is the product. Insperity's published structure segments clients into under 50, 50 to 149, and 150 to 5,000 employees, with different service configurations by tier. If you have an office manager doing HR on the side and you want a named human to call, this is the more deliberate design of the two. ADP also assigns an HR business partner, but Insperity has built its whole positioning around that relationship for forty years.

The Workday route, which is genuinely new. On February 26, 2026, Insperity and Workday announced general availability of Insperity HRScale, which pairs Insperity's PEO and HR services with Workday HCM, US Payroll, Absence Management and Time Tracking. This matters for one specific buyer: the company that wants PEO style benefits and compliance support but expects to outgrow small business HR software. Most comparison content written before 2026 does not mention HRScale at all, and some of it still refers to Insperity HRCore by its old name, Workforce Acceleration.

A clearly stated upper bound. Insperity publishes a tier that goes to 5,000 employees. If you are at the larger end of the middle market and want to know that the provider has a designed answer for your size rather than an exception, that is stated up front.

What neither will tell you

Here is the structural point that decides more PEO outcomes than any feature list, and neither company has an incentive to explain it.

Under the Affordable Care Act, a carrier in the individual and small group markets may vary premium on only four things: age, within a 3:1 band for adults, tobacco use, within a 1.5:1 band, family size, and geography. That is section 2701 of the Public Health Service Act, 42 U.S.C. 300gg, and its regulation at 45 CFR 147.102, both of which provide that the rate must not vary by any other factor. Health status, claims experience, gender, industry and occupation are all other factors, so all of them are out. Federally, small group means 1 to 50 employees under the PACE Act. California, New York and Vermont extend it to 100. Colorado moved back to 50 starting in 2026.

That rule covers small groups only: 1 to 50 employees in most states, and up to 100 in California, New York and Vermont. Above that line the math changes. A large group carrier can rate your group on its own claims experience, so a healthy large group already gets credit for being healthy, and a PEO pool has to beat an experience rated quote rather than a community rated one. For those employers the case for a PEO rests more on administration, compliance, workers compensation and multi state payroll than on the health premium.

So if your company is inside the small group definition in your state, your current renewal already ignores how sick or healthy your people are. A PEO master plan does not. It is a large group or pooled arrangement, and it is rated on the pool and on your experience within it.

That produces a result nobody selling a PEO says out loud. A PEO master medical plan is a discount for groups whose real claims risk is worse than their age, zip code, family mix and tobacco status imply, and a tax for groups whose real risk is better than those factors imply. A young, healthy, low utilization workforce in a small group state is often already buying insurance below its true cost, and moving to a pooled PEO plan can hand that advantage away. A group with a rough claims history can be buying below its true cost inside the PEO. Both ADP TotalSource and Insperity will quote you enthusiastically either way.

The second thing neither will volunteer is who actually buys PEO. According to NAPEO's October 2025 research report on PEO clients, which is industry funded and should be read with that in mind, 85 percent of PEO clients have fewer than 50 employees: 16 percent at 1 to 4, 19 percent at 5 to 9, 24 percent at 10 to 19 and 26 percent at 20 to 49. Only 9 percent have 50 to 99 employees and 6 percent have 100 to 499. If you are a 200 person company, you are in the top few percent of the PEO client base, and the master plan you are being offered was priced largely around companies a tenth of your size.

How to actually decide

Feature grids will not separate these two. Your census and your claims will.

1. Build the census first. Ages, home zip codes, coverage tier for each enrolled employee, and tobacco status. That is the exact data an ACA compliant small group rate is built from, and it tells you what the open market would charge you before anyone quotes a PEO.
2. Get your claims experience if you can. If you are self funded or level funded, you already have it. If you are fully insured and above roughly 50 enrolled, many carriers will release a high level claims summary or large claimant report on request. Without this you are deciding blind on the single largest line item.
3. Confirm your state's small group threshold. A 75 employee company in New York is small group and cannot be rated on health status. The same company in Texas is large group and can be. This one fact can flip the answer.
4. Separate the administrative fee from the benefits. Ask both to quote the per employee per month administrative fee as its own number, then price medical, workers compensation and state unemployment separately. PEO proposals are frequently bundled in a way that resists comparison on purpose.
5. Price your own workers compensation and unemployment. A clean experience modifier and low unemployment rates can make a PEO master program more expensive than what you already have. A poor modifier can make it a bargain.
6. Check the contracting entity, and model year two. Get the legal entity name that will appear on your agreement and search it on the IRS active CPEO list. Then ask both whether the administrative fee is contractually fixed and how the medical renewal is calculated if claims run high.

Frequently asked questions

Is ADP TotalSource or Insperity cheaper?

Neither publishes pricing, so any specific figure you find online is an estimate rather than a quoted rate. Both quote only after reviewing a census. Because most of the cost in a PEO is medical, workers compensation and unemployment rather than the administrative fee, the cheaper of the two depends on your workforce, not on a list price.

Are ADP TotalSource and Insperity both IRS certified PEOs?

Yes. Both appear on the IRS active CPEO list. Eighteen ADP TotalSource entities are certified with an effective date of January 1, 2017. Insperity PEO Services, L.P. is certified effective January 1, 2017 and Insperity PEO HR, Inc. effective January 1, 2026. Certification attaches to legal entities, so confirm the specific entity named in your agreement.

Are both ESAC accredited?

Yes. ESAC's own verification site lists ADP TotalSource as accredited since December 22, 1995 and Insperity as accredited since December 22, 1996. ESAC accreditation covers financial, ethical and operational standards and is verified on an ongoing basis.

What is Insperity HRScale?

Insperity HRScale is a solution that combines Insperity's PEO model and HR services with the Workday HCM suite, including Workday US Payroll, Absence Management and Time Tracking. Insperity and Workday announced general availability on February 26, 2026. It is a separate offering from Insperity's core PEO and from Insperity HRCore, which was previously called Workforce Acceleration.

What size company does each one want?

ADP states that TotalSource supports businesses with 5 to more than 1,000 employees across all 50 states. Insperity publishes three tiers: under 50 employees, 50 to 149, and 150 to 5,000. Neither publishes a hard minimum for a quote.

Will a PEO always lower my health insurance cost?

No. A PEO master plan is rated on pooled experience, while a small group plan under ACA rules may be rated only on age, geography, family size and tobacco use. Small groups whose actual claims risk is better than those four factors suggest frequently pay more inside a PEO, not less. The only way to know is to compare a real PEO quote against a real open market quote on the same census.

Next steps

If you want these two priced against each other and against your open market options on one model, we can run that comparison. If you would rather read how the process works first, start with the PEO broker overview.

Book a call

Related pages

• Independent PEO Broker
• TriNet vs ADP TotalSource
• Rippling vs Justworks
• Justworks vs Gusto
• Knowledge Center

Sources

• IRS active CPEO list (PDF, report date 8/7/2026) and the IRS CPEO public listings page.
• ESAC verification: ADP TotalSource, Insperity, and ESAC standards and procedures.
• ADP TotalSource PEO page (5 to 1,000+ employees, all 50 states, CPEO and ESAC claim, dedicated HR business partner) and ADP Form 10-K (founded 1949).
• Insperity home page (size tiers, since 1986), Insperity HRScale general availability, February 26, 2026, and Insperity's SEC Exhibit 99.2 (HRCore formerly Workforce Acceleration).
• ACA rating factors: 42 U.S.C. 300gg and 45 CFR 147.102.
• Small employer definition: 45 CFR 144.103 and the PACE Act, Public Law 114-60.
• State thresholds: California Health and Safety Code 1357.500, New York Insurance Law 3231, 33 V.S.A. 1811, Colorado SB24-073 with the Colorado Division of Insurance notice, and Texas Insurance Code 1501.002.
• NAPEO, "PEO Clients: Who They Are, Where They Are, and What They Do," McBassi & Company, October 2025 (PDF).