What states does Tandem HR serve?

Tandem HR currently operates in the following states: IL, IN, WI, MN, OH, MI, MO, IA, KY, TN, GA, FL, TX, AZ, CO, CA, NY, NJ, PA, NC.

Is Tandem HR IRS CPEO certified?

Yes, Tandem HR is an IRS Certified Professional Employer Organization (CPEO). This certification means they have met strict financial, reporting, and background requirements set by the IRS, providing additional tax advantages and liability protections for client companies.

What size companies does Tandem HR work with?

Tandem HR typically serves businesses with 10 to 1000 employees. If your company is outside this range, contact them directly to discuss your options.

What services does Tandem HR provide?

Tandem HR offers the following HR and employer services: Payroll Processing, Employee Benefits, HR Management, Workers Compensation, Compliance Support.

How do I get a quote from Tandem HR?

You can request a quote using the contact form on this page. Our advisory team will review your business and match you with the PEO provider — or providers — best suited to your needs, which may include Tandem HR.

Tandem HR

IRS CPEO CertifiedRegional PEOIL-Headquartered

Westchester, IL·Founded 1998·Serving 10-1000 employees

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States Served

Services

Industries

10-1000

Serving

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About Tandem HR

Tandem HR is a Westchester, Illinois-based PEO founded in 1998, providing payroll, benefits administration, HR support, workers' compensation, and compliance services to small and mid-sized businesses. Known for its personalized service model and dedicated HR advisor approach, Tandem HR is a recognized NAPEO member that serves clients primarily in the Midwest with national coverage for multi-state employers.

Certifications

IRS Certified PEO (CPEO)

Certification active · Verified by PEO Authority

Certified ✓

The IRS Certified PEO (CPEO) designation is awarded by the Internal Revenue Service to PEO companies that meet rigorous standards for financial health, tax compliance, and operational integrity. Tandem HR holds CPEO status — a distinction held by fewer than 15% of PEOs in the United States.

Federal Tax Liability

As a CPEO, Tandem HR assumes sole liability for federal employment taxes on wages paid — protecting your business from tax exposure.

Annual Financial Audits

CPEOs undergo independent CPA audits annually and must maintain a surety bond, ensuring fiscal accountability and solvency.

IRS Reporting

Tandem HR files employment taxes under their own EIN as CPEO, simplifying your year-end tax obligations and eliminating duplicate filings.

Why businesses choose Tandem HR

✓IRS CPEO certified and ESAC accredited - the only CPEO headquartered in Illinois with both designations

✓Founded in 1998, Tandem HR grew into the largest privately held PEO in the Midwest

✓Among the first class of PEOs nationally to receive IRS CPEO certification when the program launched in 2017

✓First PEO in the US to offer a Blue Cross and Blue Shield of Illinois group health plan to clients

✓High-touch model with dedicated HR generalist, benefits specialist, risk manager, and payroll specialist per client

Company Details

Headquarters

Westchester, IL

Founded

1998

Serving

10-1000 employees

CPEO Certified

Yes - IRS Verified

ESAC Accredited

Coverage

20 states

Company Type

Regional PEO

Tandem HR in Your State

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Pros & Cons

Pros

✓

Only Illinois-Headquartered CPEO and ESAC Dual Credential

Tandem HR holds the unique position of being the only IRS-certified CPEO and ESAC-accredited PEO with headquarters in Illinois. For Chicago and Illinois businesses, this means CPEO tax protections combined with deep local market expertise and face-to-face service availability.

✓

Dedicated Four-Person Client Team Model

Every Tandem HR client receives a dedicated team consisting of an HR generalist, benefits specialist, risk manager, and payroll specialist. This model eliminates the generic call center experience and ensures consistent, knowledgeable support across all HR functions.

✓

Broker-Friendly Approach with Carve-Out Option

Unlike most PEOs that force clients to abandon their existing insurance broker relationships, Tandem HR actively works alongside insurance brokers and allows carve-outs. This is a meaningful differentiator for companies with existing broker relationships they want to preserve.

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Cons

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Vensure Integration Transition

The 2024 acquisition by Vensure Employer Solutions introduces a transition period. Platform integrations, service structure, and account team continuity may evolve as Tandem HR integrates with the broader Vensure family of companies.

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Midwest Primary Strength

Tandem HR built its reputation and service infrastructure in the Chicago and Midwest market. While it serves clients nationally, businesses with primary operations in other regions may find PEOs with deeper local presence in those markets more responsive.

PEO Authority Editorial Note

Tandem HR is the largest privately held PEO in the Midwest and the only IRS-certified, ESAC-accredited CPEO headquartered in Illinois. Founded in 1998 by benefits consultant Bruce Leon, the firm was built on a high-touch service model that assigns every client a dedicated four-person team covering HR, benefits, risk, and payroll. In 2024, Tandem joined the Vensure Employer Solutions family, gaining expanded benefit resources while maintaining its distinctive Chicago-area service culture.

Frequently Asked Questions

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