BambooHR vs Justworks vs TriNet: PEO & HRIS Pricing Playbook

A company with 25 employees faces three purchases that all get called "HR software." BambooHR sells the software and leaves the employer of record where it is: you. Justworks sells co-employment — it becomes the employer of record for tax and benefits — at a flat fee per head. TriNet sells the same model, on a quote.

HRIS, PEO, and outsourced HR are three different purchases

BambooHR is an HRIS — a human resources information system. It stores employee records, runs time-off approvals, tracks applicants, and measures engagement. It files no payroll taxes, holds no workers' comp policy, and becomes no one's employer. Payroll, benefits administration, and time tracking are add-ons with unpublished prices.

Justworks and TriNet are PEOs — professional employer organizations. Under a PEO contract the provider becomes a co-employer: it runs payroll under its own Employer Identification Number (EIN), files the employment taxes, administers benefits on large-group terms, and carries the workers' comp policy, while the client keeps day-to-day control of the work. That is the whole price difference: BambooHR charges for software, a PEO charges for software plus the machinery of employment itself.

The distinction has a statutory anchor. A Certified Professional Employer Organization (CPEO) is a PEO the IRS has certified under Internal Revenue Code section 7705, and section 3511(a)(1) provides that a CPEO "shall be treated as the employer (and no other person shall be treated as the employer)" of a worksite employee — but only for remuneration the CPEO itself remits.

The IRS publishes the CPEO list and updates it by the 15th day of the first month of every calendar quarter. A CPEO must post a surety bond equal to 5 percent of its section 3511 liability, from $50,000 to $1,000,000, on Form 14751 within 30 days of its certification notice. Before signing, match the exact legal entity name and EIN on the contract against the IRS list.

The verified prices

BambooHR publishes three tiers. The headline rounds to $10, $17, and $25 per employee per month; the pricing FAQ gives the precise starting figures above 25 employees — $10.25 for Core, $17.50 for Pro, $25.00 for Elite — and flat monthly rates of $250, $425, and $650 for 25 employees or fewer. Volume discounts apply automatically; nonprofits receive an additional 15 percent off.

Justworks is the only PEO of the three that publishes prices. Payroll is $8 per employee per month plus a $50 monthly base fee. PEO Basic is $79 per employee per month with no base fee. PEO Plus is $124 with no base fee. The global employer of record plan is $599. The page states there is no implementation fee. PEO Basic includes payroll, multi-state payroll, tax filings, W-2 and 1099 filings, SUI administration, workers' comp access, EPLI, HR consulting, a 401(k), and 24/7 support. PEO Plus adds medical, dental, and vision administration, HSA/FSA, mental health, and fertility benefits. Published add-ons run $8 to $39 per head: time tracking $8, dedicated HR consulting $30, international contractors $39, US-based contractors $8, Payroll plus health insurance $8, and CHOICE $25 per month.

TriNet publishes no PEO price. Its pricing page is a quote funnel in three steps — tell us about your company, meet with us, receive your estimate — with pricing by company size and services needed. The model is disclosed: a flat per-employee-per-month fee, never a percentage of payroll, with benefits, workers' comp, payroll taxes, and add-ons billed separately, and payroll taxes that stop automatically at thresholds such as the Social Security wage base. Third-party reviewers put TriNet PEO at roughly $100 to $160 per employee per month, and HR Plus at roughly $10 to $33 — reported ranges, not TriNet figures.

Worked math 1: annual cost at 10, 25, and 50 heads

BambooHR's 10- and 25-employee rows are identical: the flat rate does not move below 26 heads. Justworks' Payroll plan at 10 employees costs $130 a month against BambooHR Pro's $425 — but the two are not the same purchase.

The honest comparison is BambooHR Core against Justworks PEO Basic: software-only against co-employment, a gap of $68.75 per employee per month:

At 25 employees the PEO costs 7.7 times the HRIS — the price of the co-employment machinery: the PEO's EIN on the filings, large-group benefits access, EPLI, workers' comp, and SUI administration. The Basic-to-Plus upgrade is $45 per employee per month — $13,500 a year at 25 heads, $27,000 at 50 — for benefits administration, not more software. Run the same arithmetic with our Tax & Quarterly Estimator for the employer tax side.

Worked math 2: the flat-rate trap and the crossover

BambooHR's flat rate is generous at 25 heads and punishing at 10: at 10 employees, Core costs $25.00 per head per month — two and a half times its $10.25 headline rate — while Pro is $42.50 and Elite $65.00, close to PEO Basic territory for a product that files nothing.

The crossover between BambooHR Pro and the Justworks Payroll plan, in the per-employee zone above 25 heads, is exact:

Above roughly six employees, the Justworks Payroll plan costs less per month than BambooHR Pro on platform fees alone — not the better buy, since Pro includes performance management, recognition, and 15 compliance courses the Payroll plan does not. At 50 heads, BambooHR Core at $512.50 a month still costs $62.50 a month more than the Justworks Payroll plan at $450 — $750 a year — for a product that does not run payroll.

Worked math 3: what the fee does not include

No fee here includes the three costs that dominate real employer spend: benefits premiums, workers' comp premiums, and employment taxes. The PEO fee is the administration layer.

Employer FICA is 7.65 percent of wages — 6.2 percent Social Security under section 3111(a) plus 1.45 percent Medicare under section 3111(b) — and at a $65,000 average salary:

Justworks PEO Basic at 25 heads costs $23,700 a year — 19.1 percent of the FICA line alone. State unemployment insurance (SUI) varies by state and experience rating, which is why Justworks lists SUI administration as a feature, not a price.

The loaded comparison is fee plus premiums plus taxes. A 25-person team on Justworks PEO Plus pays $37,200 a year in platform fees, then health, dental, and vision premiums for every enrolled employee, then workers' comp premiums priced on payroll and class codes, then $124,312.50 in employer FICA on a $65,000 average salary. A team on BambooHR Core pays $3,000 and buys the same benefits, workers' comp, and tax filings directly. BambooHR's 15 percent bundle discount is a real discount on two add-ons whose prices it does not publish — a negotiation lever, not a budget number.

The decision table: who should buy which

Operator boundaries: who should not buy a PEO

A PEO is the wrong purchase for four kinds of buyer. First, a company with no US W-2 employees: there is nothing to co-employ. Second, a company whose benefits already beat the PEO's large-group offering — a negotiated plan through a broker, or a team on a spouse's coverage — because the headline benefit disappears and only the admin fee remains. Third, a company in a niche the PEO declines to underwrite: workers' comp underwriting is the PEO's risk decision, and a declined census ends the sales process. Fourth, a company that must keep its own EIN on filings: under section 3511 the CPEO is treated as the employer for the remuneration it remits. A buyer who wants the benefits desk without co-employment should buy TriNet HR Plus, or stay on an HRIS and hire a benefits broker. An LLC, an S-Corp, and a C-Corp all face the same FICA and FUTA arithmetic.

Execution checklist: buying in 30 days

• [x] Count the heads honestly: W-2 employees only, by state, with salaries. Contractors are not employees; Justworks prices them at $8 per paid contractor.
• [x] Pick the model before the vendor: HRIS, PEO, or outsourced HR. The model is the decision.
• [x] Price the loaded cost, not the headline: fee plus premiums plus workers' comp plus FICA at 7.65 percent plus FUTA at $42 net.
• [x] Get the TriNet quote in writing: census, states, industry, and benefit elections attached, with fee and pass-throughs itemised.
• [x] Verify CPEO status on the IRS list: exact legal entity name and EIN from the contract, plus the suspended and revoked lists.
• [x] Ask BambooHR for the add-on prices in writing: Payroll, Benefits Administration, and Time & Attendance are unpublished, so the 15 percent bundle discount cannot be budgeted until quoted.
• [x] Have your CPA reconcile the first invoice: fee, premiums, workers' comp, and tax deposits against the quote, before the second pay run.
• [x] Wire onboarding before the first hire: I-9 verification, E-Verify where used, state withholding forms, benefits enrollment.

The 30-day protocol

1. Freeze the census — headcount, states, salaries, and benefit elections in one sheet.
2. Request two written quotes — BambooHR with add-ons priced and one PEO — for the same census.
3. Run the 10/25/50 arithmetic — platform fees at all three headcounts, checked against published prices.
4. Verify the CPEO on the IRS list — entity name and EIN matched, suspended and revoked lists checked.
5. Price the loaded cost — premiums, workers' comp, FICA, and FUTA added to the fee; compare totals, not headlines.
6. Run one parallel pay cycle — new platform beside the old process for one pay period, reconciling every tax deposit.
7. Sign, then audit the first invoice — the CPA reconciles it against the quote line by line before the second pay run.

The payroll side has its own arithmetic: the ADP vs Gusto vs Paychex playbook prices the payroll-only vendors, and the Gusto vs Rippling vs QuickBooks playbook covers the employer cost stack underneath every platform.