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LeadChange Group

ASO Services

Best ASO Services for Mid-Sized Companies

Mid-sized companies with an HR manager use an ASO to take payroll, benefits administration and compliance work off the team while keeping control of benefit plans, carriers and HR decisions. The choice turns on how modular the services are and how well the platform handles several states.

products that fit
10
By LeadChange Research TeamUpdated Based on 19 sources, most recently checked

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Top 3 by LeadChange Score, then 7 not scored yetof 10 that fit · 7 not scored yet · scored for mid-sized companies (reweighted)

  1. Paychex HR Pro and HR Partner Plus5.1 out of 10, High confidence
  2. TriNet HR Plus4.8 out of 10, High confidence
  3. Easeworks ASO3.6 out of 10, Medium confidence
  4. Connor & Gallagher OneSource ASONot scored yet
  5. G&A Partners ASONot scored yet
  6. Insperity HRCoreNot scored yet
  7. ADP Comprehensive ServicesNot scored yet
  8. C2 Essentials ASONot scored yet
  9. AsureWorksNot scored yet
  10. INFINITI HR ASONot scored yet

See the full rankingHighMedium confidence

ASO services for mid-sized companies, ranked

Ranked by LeadChange Score from verified facts; products with too few verified facts are not scored yet and come last. Scores are for ASO services, so a product's score or «not scored yet» here can differ from its own page, which scores its main category. Prices are list prices as published by each vendor.

Filter by verified facts

  1. Paychex HR Pro and HR Partner Plus

    Scored 7.2/10 in Payroll Software on its own page

    Paychex's HR packages add HR guidance, HR technology and benefits administration to Paychex Flex payroll without shared employer responsibility: the business files payroll taxes under its own EIN and manages its own workers' compensation policy.

    Paychex Flex plans and prices

  2. TriNet HR Plus

    Scored 6.9/10 in PEO Services on its own page

    TriNet HR Plus is TriNet's ASO: HR, payroll, benefits and time in one system with access to experienced HR and payroll professionals, while the business stays the employer of record for payroll tax purposes. TriNet remits and files federal, state and local payroll taxes.

    SOC 2 Type II
    Yes (per its 2023 white paper)1
    TriNet pricing

  3. Easeworks ASO

    Easeworks is a California HR outsourcing firm, operating since 2000, whose ASO keeps the client as sole employer while Easeworks runs payroll and tax support, HR administration, compliance workflows and reporting with a named HR partner.

    Pricing model
    Quote only2
    What Easeworks ASO costs

  4. Connor & Gallagher OneSource ASO

    Connor & Gallagher OneSource (CGO), an insurance agency founded in 1997, sells an ASO that bundles UKG Ready payroll and HRIS with HR management outsourcing, employee benefits, retirement plan services and workers' compensation, while the client remains the employer. UKG Ready is required and pricing is quoted.

    Pricing model
    Quote only3
    Not scored for this segment11 of 19 facts verifiedWhat Connor & Gallagher OneSource ASO costs

  5. G&A Partners ASO

    Scored 7.3/10 in PEO Services on its own page; too few administrative services organization facts verified to score it here

    G&A Partners' ASO provides HR outsourcing without a co-employment relationship. Its packages let a business mix payroll, benefits administration and HR support, priced by quote.

    Not scored for this segment11 of 19 facts verifiedG&A Partners pricing
Show all 10 products
  1. Insperity HRCoreNot scored yet (11 of 19 facts verified) · Scored 5.7/10 in PEO Services on its own page; too few administrative services organization facts verified to score it hereInsperity pricing
  2. ADP Comprehensive ServicesNot scored yet (10 of 19 facts verified)What ADP Comprehensive Services costs
  3. C2 Essentials ASONot scored yet (10 of 19 facts verified)C2 Essentials ASO pricing
  4. AsureWorksNot scored yet (9 of 19 facts verified)AsureWorks pricing
  5. INFINITI HR ASONot scored yet (8 of 19 facts verified) · Scored 5.7/10 in PEO Services on its own page; too few administrative services organization facts verified to score it hereINFINITI HR pricing

LeadChange Score: editorial assessment based on public information.

All administrative services organizations (ASO), ranked

How the score works

How many employees would the PEO cover?

Some products only serve certain team sizes: those that do not fit yours drop out.

What matters for mid-sized companies

  1. Modular services

    Look for a provider that lets you outsource payroll, benefits or HR administration separately and add services as the team changes.

  2. Benefits administration for your plans

    Check carrier connections, ACA filing and COBRA administration for the plans you sponsor, since an ASO does not offer its own group plans.

  3. Multi-state payroll and compliance

    Ask which states the provider files in and how it tracks state and local law changes for your locations.

More tools for mid-sized companies

Find your fit

By industry

Best administrative services organization for constructionBest administrative services organization for educationBest administrative services organization for governmentBest administrative services organization for healthcareBest administrative services organization for hospitalityFor LogisticsBest administrative services organization for manufacturingBest administrative services organization for nonprofitsBest administrative services organization for restaurantsBest administrative services organization for retail

By company size

Best administrative services organization for enterprisesMid-Sized CompaniesBest administrative services organization for small business

Frequently asked questions

What are the best ASO services for mid-sized companies?

On the LeadChange Score weighted for mid-sized companies, the highest-scoring of the 3 products with a published score are Paychex Flex (5.1/10), TriNet (4.8), and Easeworks ASO (3.6).

Which ASO services for mid-sized companies include workers’ compensation?

Connor & Gallagher OneSource ASO, G&A Partners, INFINITI HR, Insperity (PEO), and TriNet handle workers’ compensation as part of their service; Easeworks ASO and Paychex Flex do not include it. That is 5 of the 10 ASO services for mid-sized companies.

Which ASO services for mid-sized companies integrate with QuickBooks?

4 of the 10 ASO services for mid-sized companies document an integration with QuickBooks: INFINITI HR, Insperity (PEO), Paychex Flex, and TriNet.

Which ASO services for mid-sized companies have a mobile app?

ADP Comprehensive Services, G&A Partners, INFINITI HR, Insperity (PEO), Paychex Flex, and TriNet confirm a mobile app; 4 of the 10 products for mid-sized companies have none on file.

Which ASO services for mid-sized companies support single sign-on?

G&A Partners and TriNet document single sign-on; 8 of the 10 products for mid-sized companies have none on file.

Which ASO services for mid-sized companies run payroll and file payroll taxes?

ADP Comprehensive Services, AsureWorks, C2 Essentials ASO, Easeworks ASO, G&A Partners, Paychex Flex, and TriNet run payroll and file payroll taxes under the client’s own tax ID, according to their own documentation. 3 of the 10 ASO services for mid-sized companies do not publish it.

Which ASO services for mid-sized companies administer the client’s own benefit plans?

ADP Comprehensive Services, AsureWorks, C2 Essentials ASO, Connor & Gallagher OneSource ASO, Easeworks ASO, and 4 more administer enrollment and eligibility for the client’s own benefit plans, according to their own documentation. One of the 10 ASO services for mid-sized companies does not publish it.

Which ASO services for mid-sized companies give access to HR advisers?

ADP Comprehensive Services, C2 Essentials ASO, Connor & Gallagher OneSource ASO, Easeworks ASO, G&A Partners, and 4 more give managers access to HR advisers, according to their own documentation. One of the 10 ASO services for mid-sized companies does not publish it.

Which ASO services for mid-sized companies administer the client’s workers’ compensation policy?

Connor & Gallagher OneSource ASO and G&A Partners administer the client’s own workers’ compensation policy, according to their own documentation; Paychex Flex states that it does not. 7 of the 10 ASO services for mid-sized companies do not publish it.

How we research

This ranking of ASO services for mid-sized companies reweights the LeadChange Score: capability coverage 25%, pricing transparency & value 30%, integrations & API 10%, security & compliance 10%, fit & support 15%, and data confidence 10%. Only products with a verified fact showing they serve this segment are listed.

How this page was made

  • What it is built from

    23 verified facts, each checked against the vendor's own pages or another primary source, most recently on Nov 11, 2026.

  • Method

    Scored and compared with the LeadChange methodology, version 1.5. Read the methodology

  • Independent review

    Not reviewed yet by our independent reviewer. How we review

  • Hands-on testing

    We have not tested these products hands-on: this page uses public information only.

  • Who made it

    The LeadChange Research Team, following a written research process. No named expert has reviewed this page. About us

  • Independence and errors

    Who pays us never changes a score or a rank. If something here is wrong, tell us and we correct it publicly. Request a correction

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Sources

The 19 pages this page's facts come from. The date beside each is our last check of the facts taken from it (the oldest, when they differ). The numbers beside the figures above link here.

Quotes from the sources
  1. TriNet assets.contentstack.io/v3/assets/blt9ccc5b591c9e2640/blt2147f424591a508f/657239817631d147b77ffb80/TriNet_Security_and_Privacy_White_Paper_2023.pdf“a SOC 2 Type 2 report for the TriNet platform. Current copies and corresponding bridge letters (issued each calendar quarter) are available upon request and are reserved for existing customers.”
  2. Easeworks easeworks.com/pricing“Your current costs next to the Easeworks number, item by item — admin fee included, nothing folded in or hidden.”
  3. Connor & Gallagher OneSource gocgo.com/aso-provider“CGO can review your current structure and help determine whether an integrated ASO model makes sense for your organization.” “Workers' compensation is another component of the ASO model.”
  4. Internal Revenue Service irs.gov/pub/irs-sbse/active-cpeos.pdf“Insperity PEO Services, L.P. 19001 Crescent Springs Drive KINGWO OD TX 77339 US 1/1/2017” “INFINITI HR, LLC 3905 National Drive Suite 400 BURTONS MD 20866 US 10/1/2018”
  5. G&A Partners gnapartners.com/peo“Risk management and safety services, including workers’ compensation and claims assistance”
  6. INFINITI HR infinitihr.com/resources/faqs“Employer Mandatory Insurance True-Group Workers’ Compensation and EPLI”
  7. Insperity insperity.com/our-products/hr360“We take on certain employer responsibilities, such as handling payroll and related tax filings, maintaining workers’ compensation coverage and providing employees access to benefits.”
  8. TriNet trinet.com/peo/pricing“The PEPM fee generally covers payroll processing and payroll tax administration, HR expertise, benefits administration, workers' compensation administration”
  9. Easeworks easeworks.com/aso“Can we keep our current benefits and workers’ compensation?”
  10. Paychex paychex.com/payroll/compare-payroll-solutions“Available Add-Ons for All Packages … Workers' Comp Get the coverage you need to provide monetary compensation after a workplace-related injury or illness occurs.”
  11. INFINITI HR infinitihr.com/solutions/payroll“GL interface compatible with popular accounting software (QuickBooks, Peachtree, Great Plains, Data Pro)”
  12. ADP adp.com/what-we-offer/products/adp-comprehensive-services/compare-options.aspx“ADP mobile app”
  13. G&A Outsourcing, Inc. apps.apple.com/us/app/g-a-partners-mobile/id1550192429“G&A Partners - Mobile application enables an employee to view important details such as payroll information, download a paystub, view and request PTO, punch in and out via an online timeclock, see an organizational chart and manage their WorkSight account details.”
  14. INFINITI HR infinitihr.com/media/releases/infiniti-hr-unveils-new-mobile-app-for-enhanced-employee-management“The INFINITI HR mobile app is now available for download on the App Store and Google Play.”
  15. Insperity, Inc. (App Store listing) apps.apple.com/us/app/id674606949“Insperity Mobile is now in sync with your active lifestyle. Quick, easy access to your 401k, paycheck information, FSA, UHC benefits card and more.”
  16. Paychex paychex.com/apps/mobile-app“Employees can download the Paychex Flex® app for free from the Apple App Store or Google Play Store and log in using their Paychex account credentials.”
  17. TriNet trinet.com/peo“Our platform also lets your employees view pay stubs and request time off conveniently from our mobile app.”
  18. G&A Partners gnapartners.com/hr-technology“G&A Partners simplifies HR by centralizing key functions into a single integrated platform with a single sign-on (SSO).”
  19. TriNet trinet.com/customer-resource-center/technology/integration-center“Identity Providers and Single Sign-on – Microsoft® Azure, Google™ Cloud, Okta™, OneLogin™”

What the LeadChange Score means

A 0–10 editorial assessment built only from verified facts, across six weighted dimensions: capabilities, pricing, integrations, security, fit and support, and data confidence.

Payments, commissions and lead fees are never inputs.