PEO Glossary: Every Term Explained, Sourced

Written by Peolet Editorial · Reviewed by Peolet Editorial · Last verified 2026-07-27

A

ACA measurement period. The employer-mandate mechanic that decides who counts as full-time: hours are measured over a measurement period of up to twelve months, eligibility is applied during an optional administrative window, and a stability period then locks in the employee's status. Under a PEO arrangement the tracking usually runs on the provider's platform, because your people's medical coverage sits inside its group plans. It matters most for part-time workforces, where the same employees cross the threshold as hours move.

ACH run. The electronic payroll funding batch: you fund the provider's payroll account ahead of payday, and the PEO debits it and pushes net pay to employees' bank accounts, with tax and benefits bills settled in the same cycle. The mechanics that matter to a buyer are the funding deadline, the timing of the collection, and what happens when a run fails after you have already funded it.

Administrative fee. The provider's actual charge for the service, before insurance and statutory pass-throughs are bundled in. The single number you need separated from every quote — and the only line the provider actually earns on the arrangement. Ask what it covers, and read how the contract lets it change: fee-increase mechanics live in the renewal clause, and some agreements cap them. How to force one out of a sales team.

Alternative workers' compensation financing. Programs some PEOs and their carriers use to reshape how premium is paid: large-deductible arrangements, group captives and guaranteed-cost structures. They can stabilise cash flow or lower the quoted premium, and they complicate the exit — a deductible or captive exposure does not end when the master policy does. Ask which financing model your quote assumes before you compare it with another provider's.

ASO (administrative services organization). A vendor that administers HR and payroll while you remain the sole employer, with your own benefit plans, broker and unemployment account. Your EIN stays the reporting employer, and your unemployment experience rating, benefit plans and broker all stay yours — an ASO moves administration, not employer status. PEO vs ASO.

Auto-renewal. The default renewal mechanic of most PEO agreements: a fixed initial term renews automatically on its anniversary, so doing nothing extends the contract. The only lever is the cancellation window — the calendar deadline for written notice of non-renewal — and it has to be in the provider's verified terms before you sign, not after. The contract-terms table records the windows we have verified.

B

Base fee + module pricing. A fee shape that quotes a per-employee rate plus a separate monthly base fee and paid modules — benefits administration, compliance, employer-liability coverage — on top of it. Comparisons on the PEPM number alone fail, because the quoted rate excludes modules the other provider bundles. What a PEO costs.

C

Cancellation window. The period before renewal or the term anniversary within which written notice must land for you to exit without penalty. Miss it, and the agreement auto-renews for another term even if the service is failing. The site records each provider's verified term and notice window on the contract-terms table, with sources and verification dates.

Carrier disclosure. The paperwork by which a PEO tells its workers' compensation and benefits carriers who the worksite employees are, which class codes their work carries, and under which master policy they sit. Carriers audit payroll and class-code reports, so the accuracy of what is disclosed is what your coverage rests on — and disclosure questions belong on the exit list as much as the entry list.

Certified PEO (CPEO). A PEO that has met IRS requirements, including bonding and annual independent financial audits, and appears on the IRS public list. It changes who is liable for federal payroll taxes and what happens to your wage bases on a mid-year move. Certification attaches to a named legal entity, not a brand — check the entity in your service agreement, because large providers run several and not all are certified. It does not cover state taxes or contract terms. The full difference.

Check run. The paper-payroll path some employees still take: a physical check issued from the provider's account rather than an electronic transfer. Ask what a check costs per piece and who signs it, and note that the funding sequence behind it is the same pooled cycle as the electronic run.

Client service agreement. The contract between you and the PEO. Where exit fees, notice periods, indemnification and the split of responsibilities actually live. The term, the cancellation window and the fee mechanics resolve in this document, and the exhibits — allocation of employer responsibilities, fee schedule, class-code list — are the product in detail. Read it before you believe the brochure, and keep the signed packet. Hidden fees.

COBRA. The federal continuation-coverage mechanic: when group health plan coverage would end on a qualifying event — termination, reduction in hours, a family change — the plan must offer continuation for a limited statutory period, with the employee paying the full premium. Under a PEO, the offer runs through the provider's group plans, and on the way out you need to know who services your former employees' continuation coverage.

Co-employment. A contractual split of employer responsibilities between you and the PEO. Both of you are employers of the same people, for different purposes. What moves is the payroll, tax and benefits machinery; direction, control and termination decisions stay with you, and wage-and-hour and classification exposure follows the party directing the work. The plain-language version.

D

Digital signature. An electronic signature on the service agreement. Federal and state electronic signature laws give signed documents the same force delivered electronically as on paper, so the version you click through — including the exhibits — is the contract. Save the signed packet and the dated acceptance record; the brochure is not the agreement.

E

EOR (employer of record). A company that becomes the sole legal employer on its own entity, used when you hire somewhere you have no legal entity. The term also appears in its narrow payroll-tax sense: a certified PEO is treated as the employer of record for federal employment taxes on the wages it pays. PEO vs EOR.

ERISA. The federal law that governs employer-sponsored benefit plans. It sets the plan, fiduciary and disclosure framework: a written plan document, a summary plan description given to participants, and annual reporting. Because PEO benefits normally run through the provider's group plans, the ERISA paperwork in the arrangement is typically the provider's — and copies of it belong in your exit folder.

ERISA plan documents. The written plan documents and summary plan descriptions that define who is covered, what the plan promises and how claims resolve. In a PEO arrangement these are usually the provider's plan documents for its group plans, not yours. Get them before enrollment, keep the copies on exit, and know who the plan sponsor is: that entry is the other half of this one.

ESAC (Employer Services Assurance Corporation). A voluntary accreditation body that reviews a PEO's financial statements, payroll tax payments and benefits funding. Accredited organizations appear in a public directory you can check in a couple of minutes. Distinct from — and complementary to — IRS certification; it is not a substitute for it.

Evergreen contract. A service agreement with no fixed end date: it stays in force until either party gives the required written notice within the cancellation window. The evergreen shape makes that deadline the only exit lever — calendar it from day one. Verified terms.

Exit fee. What leaving a PEO costs beyond the notice period: termination fees, the work of rebuilding your own payroll, benefits and unemployment accounts, and anything the agreement says about the way out. Notice mechanics often decide whether exit fees apply at all — several agreements we have verified waive the standard transition fee when the required written notice lands in time. Hidden fees.

Experience modifier (experience modification factor). The workers' compensation multiplier on your side of the premium: payroll per class code, times the class rate, times your modifier — where the modifier compares your loss history against what similar employers in your class codes produce. It follows the payroll the carrier can see, so under a master policy your history sits inside the provider's pool. Ask how the modifier transfers or is credited on the way out, in writing. State rules vary.

Experience rating. Your state unemployment insurance history, which sets your rate. Under a PEO arrangement, whether it stays yours or merges into the provider's depends on the state's reporting basis — see SUI experience rating — and it becomes acute on the way out. The workers' compensation modifier is a separate mechanism, dealt with separately. State rules vary.

F

Fixed-term contract. A service agreement with an initial term of a set length — a year in the classic shape — that then ends, converts or renews per the agreement. Fixed refers to the length, not the exit: unless notice is given within the cancellation window, most fixed terms still auto-renew. Read the term and notice lines as a pair. The contract-terms table.

Form 1099 classification. The independent-contractor question: whether a worker gets a Form 1099 instead of a W-2 turns on the facts of control and the actual work relationship — a decision about the job, not about the payroll software. A PEO can process the classification you record; it cannot know the duties. Misclassification risk sits substantially with the employer directing the work, so settle the classification before the provider processes it.

Form 5500. The annual return filed for ERISA-covered benefit plans, by the plan administrator, once a plan covers 100 or more participants. In a PEO arrangement the filings belong to the provider's plans — and on exit, the plan's Form 5500 history is part of the records to request.

Form W-2. The annual wage-and-tax statement, issued by the entity that paid the wages. In a PEO arrangement that is the provider: its EIN appears on the forms for the payroll it ran, and employees see a new employer name at year-end. State wage reporting follows the jurisdictions where people worked — tell staff before the forms arrive.

FSA (flexible spending account). The pre-tax spending mechanic of a Section 125 plan: employees elect a dollar amount for health or dependent-care expenses, it is deducted before tax, and unspent balances are lost under use-it-or-lose-it, with grace periods and carryover rules depending on plan design. Under a PEO, FSA administration runs through the provider's benefits platform.

H

Health plan administration. The benefits machinery a PEO runs: enrollment, eligibility, COBRA notices, ACA tracking and reporting, and the plan documents behind its group plans. Your employer contribution is usually billed as a pass-through, and the plan design — carrier network, deductibles, contribution structure — is what you actually buy.

HSA (health savings account). The tax-advantaged account that must be paired with an HSA-qualified high-deductible health plan: contributions are pre-tax, balances belong to the employee and move with them, and the account survives leaving the PEO. Under a PEO, eligibility and contributions are administered through the provider's plans and payroll — confirm the plan is HSA-qualified before promising one to staff.

I

IRS Circular E. IRS Publication 15 (Circular E), the Employer's Tax Guide — the publication that carries the federal employment tax rules: withholding computation, deposit schedules and the forms. A PEO withholds, deposits and files on its own accounts, and a certified PEO is solely liable for the federal employment taxes on the wages it pays, so Circular E mechanics describe what the provider is doing with the money you fund.

M

Managed insurance. The claims-and-risk layer of a workers' compensation program: loss control, claims administration and return-to-work support run by the carrier or the provider's risk team under the master policy. Its quality shows up in your loss runs, and it is a real differentiator between providers — ask who answers an injured worker's call, and what the provider's claims-handling look is, in writing.

Master workers' compensation policy. A single workers' compensation policy covering the PEO's entire pool of client employees. Your people are added to it by class code and payroll estimate, you report actual payroll by class each period, and the carrier bills premium against the pool — that is what lets a small employer with hard class codes get coverage it could not place alone. Two consequences matter: your experience modifier sits inside the pool rather than on your account, and leaving mid-policy-year means the carrier completes audits and loss runs under the PEO's policy — which is what makes it awkward to unwind. Get the carrier, the class-code list the policy can carry and the exit-audit mechanics in writing.

N

NCCI (National Council on Compensation Insurance). The rating organization whose class-code system and advisory rates underpin workers' compensation pricing in most states. Where a state does not use the NCCI system, a state bureau publishes its own manual and rates. Any master-policy conversation involves one of the two: know whose manual your class codes come from. The site tracks state-bureau class-code lists per industry, with sources and dates — the industry hub and the class-code statistics page.

P

Pass-through. An insurance or statutory cost the PEO charges through to you at cost — workers' compensation premium, state unemployment tax, benefits premium. It is the layer a PEO earns nothing on, and the layer where buried markups hide: unbundling is the protection. The line between pass-through and administrative fee is where comparability lives. What a PEO costs.

PEO (professional employer organization). A company that co-employs your staff so it can run payroll, provide benefits and take on defined employment obligations, while you keep control of the work. Most providers will not quote below about five worksite employees, and above that the statutory costs — benefits, taxes, workers' compensation — pass through at cost, leaving the administrative fee as the line you actually negotiate. What a PEO is.

PEO registration. The state-level compliance screen: most states require a PEO to register or hold a licence before serving employees there, administered by a labor department, insurance department or secretary of state depending on the state, often with bonding or net-worth conditions attached. Registration is a compliance filter, not a quality signal — verify the entity against the state's own list, and a provider that is not registered where you employ people cannot legally serve them there. State pages.

PEPM (per employee per month). The flat administrative fee shape: a dollar amount per employee per month. Predictable, and favours employers whose wages are rising. What the flat rate includes varies between quotes — modules like benefits administration or compliance are often priced separately — so compare the service bundle, not just the number. PEPM vs percentage.

Percentage of gross payroll. The alternative fee shape: a percentage of what you actually pay your people. It rises with every raise, bonus and commission — and ask what it applies to: base wages only, or total cash including bonuses and commissions, because the denominator decides how the fee behaves. PEPM vs percentage.

Plan sponsor. The entity that maintains an ERISA benefit plan and carries its legal burdens: plan documents, fiduciary duties, annual Form 5500 filings. Under a PEO arrangement the provider is usually the plan sponsor for the group plans your people join; any plans you keep yourself stay yours. Know which role each party holds before an enrollment.

S

Section 125 plan (cafeteria plan). The pre-tax benefit structure: employees choose between cash and qualified benefits — health premiums, FSAs, sometimes HSAs — with elections locked in before the plan year and mid-year changes restricted to qualifying events. Under a PEO, employees' elections are normally administered inside the provider's group plan structures; ask where your elections sit before comparing tax-free benefit claims between providers.

Self-funded health plan. A plan where the sponsor pays claims from a funded trust rather than paying premiums to an insurer, with stop-loss insurance capping catastrophic claims. Under a PEO, self-funding happens at the level of the provider's group — clients generally buy into a plan whose claims pool, funding and stop-loss sit with the provider. Ask which funding model your quote assumes; it changes contribution stability and what you need to understand about the plan's finances.

Signature packet. The full bundle you sign when enrolling: the client service agreement, its exhibits — allocation of employer responsibilities, fee schedule, class-code list, implementation timeline — plus payroll authorisations and direct-deposit forms. Treat the packet as one contract: the sales conversation and the signature packet are two different documents, and only one of them governs. Some agreements even tie exit-fee waivers to the written notice specified in the packet itself.

Split-employer arrangement. The state-law reality of co-employment: who counts as "the employer" differs by tax and by state. Some states assign unemployment reporting at the client level — your account, your rate — others at the PEO level — the provider's account, pooled rate — and a few let the parties elect. The same workforce can split differently across unemployment, workers' compensation, paid leave and benefits, which is why the state pages record the reporting basis per state. State pages.

SUI (state unemployment insurance) wage base. The earnings threshold on which you pay state unemployment tax per employee. It varies by state, it is a material part of employment cost, and a PEO changes who reports it — the state pages record each state's current base and new-employer rate with sources and verification dates. State pages.

SUI experience rating. The mechanic that turns your unemployment history into a rate: benefit charges against your account and payroll history are converted into a contribution rate, often after a new-employer period at a fixed rate. Under a PEO, whether the rating stays yours or merges into the provider's pool depends on the state's reporting basis — get that answer in writing before signing, because it is worth a different premium on the way out. State pages.

SUI successor rates. The transfer mechanic between employing units: when a business's payroll and operations move to another unit, the successor can inherit the predecessor's experience and rate. After a PEO exit, this decides what rate your reborn account starts at — and state agencies watch the same transfers for abuse (see SUTA dumping).

SUTA dumping. The practice of shifting payroll into a new or separate unemployment account to dodge a higher experience-rated rate — the unemployment-tax equivalent of hiding claims history. Federal and state law both police it, and a PEO transition can look like dumping when the paperwork — successor applications, account transfers — is wrong, so a clean move matters to both parties.

W

Wage base. The earnings cap on which federal (and, separately, state) unemployment tax applies. A mid-year move to a non-certified PEO can restart your federal wage bases — and the restart is the hidden cost of timing a switch. The state side is separate and state-specific. What CPEO certification changes.

Workers' compensation class codes. The risk classification of your employees' jobs, which drives your premium. The codes come from the NCCI manual in most states and from state-bureau manuals elsewhere, and the class list your provider's master policy can carry decides whether it can cover you at all. Premium runs on payroll per class, times the class rate, times your experience modifier — which is why two businesses of identical size can pay wildly different premiums, and why published "average" PEO costs are usually meaningless for you. The site's industry pages list the state-bureau class codes on file per trade, with sources. Industry guides.

Worksite employee (WSEE). The people covered by a co-employment arrangement — your staff, doing your work, paid through the PEO. It is the term used in CPEO statute and in carrier and state paperwork, and provider minimums are quoted in worksite employees: below about five, most PEOs will not quote.

Worksite employer (WSRE). The client side of the arrangement, as some state statutes and carrier forms name it. In a minority of states the worksite employer remains the employing unit for unemployment or paid-leave reporting even while the PEO runs the payroll — the split-employer reality that makes the state pages worth reading before you sign. State pages.

Terms we refuse to use

"Partnership." A co-employment arrangement is a contract, not a partnership, and the difference shows up in the liability clauses.

"Fully burdened cost." A bundled number that hides how much of it is pass-through. Ask for the unbundled version instead — the seven questions here produce it.

Next

• What is a PEO
• What a PEO costs
• Provider directory

Related guides

• Co-employment
• EIN under co-employment
• Termination authority
• CPEO certification