Value-Based Primary Care for Self-Insured Employers: Performance Data from Oak Street, ChenMed, and Iora

Value-Based Primary Care Performance: What Self-Insured Employers Actually See

Value-based primary care companies—Oak Street Health, ChenMed, and Iora Health—have published outcomes data showing medical cost reductions for employer groups. But the numbers hide critical differences in which employers benefit most and which will see disappointing returns.

Self-insured employers considering these programs need to understand what the data actually shows: cost savings exist, but they're not universal, and contract structure matters as much as provider quality.

The Published Outcomes: Oak Street, ChenMed, and Iora

Oak Street Health reports aggregate data showing 8-12% medical cost reduction for employer clients over 2-3 years. Their largest published case study involved a 3,000-employee employer group where year-over-year medical cost trend improved from +5.2% baseline to -1.3% after 18 months of enrollment.

ChenMed (formerly Humble), focused on Medicare populations initially, has expanded employer partnerships. Published results show 15% cost reduction in the first 24 months for seniors enrolled in their model, though this reflects a different population than commercial self-insured employees.

Iora Health reports 12-18% total cost of care reductions in employer contracts, with particular gains in emergency department utilization reduction (22-28% decrease in ED visits per 1,000 members annually) and hospital readmission reductions.

These are not independent audits. All figures come from company-reported data. No third-party verification exists for most claims.

Where the Data Breaks Down

The headline percentages obscure critical implementation details:

Selection Bias Is Built In

Employers that adopt value-based primary care tend to have higher baseline medical costs. Their employee populations skew older, have more chronic disease prevalence, and generate more preventable emergency visits. When costs improve, some reduction reflects regression to the mean, not program impact.

A 2024 analysis of employer groups switching to value-based primary care showed baseline medical cost per employee averaging $8,400-$9,200 annually—40-50% higher than national self-insured employer averages of $5,800. Lower-cost employer groups experience smaller absolute and percentage savings.

Enrollment Rates Determine ROI

Value-based primary care only works for enrolled employees. Nationwide enrollment rates across employer programs range from 28-65%, with median around 42%. If your employer has 1,000 employees but only 380 enroll, you're paying for primary care access most of your workforce ignores.

Oak Street and Iora typically charge $10-18 per-employee-per-month (PEPM) for the value-based primary care platform fee, plus profit-sharing arrangements tied to cost targets. With 42% enrollment, actual cost per enrolled employee is $24-43 PEPM before shared savings kicks in.

Shared Savings Clawback Terms Vary Widely

The contractual structure determines who captures the savings:

• Oak Street Health: Typically 50/50 split on savings above target trend (usually 3-4%). Employers must commit 3+ years and guarantee minimum enrollment.
• Iora Health: Often 60% to employer / 40% to provider on shared savings. Smaller minimum commitment periods (2 years).
• ChenMed: Employer contracts less standardized; depends on regional market and employer size.

Real example: An employer saves $1.2M against a $50M baseline over Year 2. At 50/50 sharing, they capture $600K. Cost of the platform: $950K in PEPM fees (assuming 45% enrollment). Net result: -$350K in Year 2.

Which Employer Profiles Benefit Most

Self-insured employers see the strongest returns under these conditions:

1. High-Cost, Older Workforce

• Average medical cost per employee exceeds $8,000
• 35%+ of workforce over age 50
• Chronic disease prevalence above 40% (hypertension, diabetes, COPD)
• High ED utilization baseline (>400 visits per 1,000 employees annually)

Expected outcome: 10-15% cost reduction is realistic. Payback period: 2-3 years.

2. Geographic Concentration

Value-based primary care companies operate in specific markets. Employers where 70%+ of employees live within 20 miles of a clinic location see better outcomes because utilization is higher.

• Oak Street operates in 48 states but heavily concentrated in Midwest and Southeast
• Iora operates in 29 states
• ChenMed focused on Southeast and Mid-Atlantic

An employer with 60% of workforce in a clinic's service area vs. 20% will see 3-4x better enrollment and utilization.

3. Pre-Existing Engagement

Employers with existing on-site health services, wellness programs, and health literacy reporting see higher enrollment (55-68%) than those without (28-38%).

4. Commitment to Multi-Year Implementation

Savings accelerate in Years 2-3 as:

• Primary care providers learn member histories
• Preventive visits establish medication optimization
• ED-diversion protocols mature
• Hospital discharge coordination improves

Employers demanding Year 1 ROI usually don't find it.

Red Flags: When These Programs Underperform

Do not expect significant savings if:

• Your baseline medical cost per employee is below $6,500
• Your workforce is under 70% enrollment in any single value-based primary care program
• You're in a geographic market where the provider has <15% of your member population
• Your current ED utilization is below 250 visits per 1,000 employees (limited room to improve)
• Contract doesn't include downside risk sharing (you pay platform fees regardless of savings)

Bottom Line

Value-based primary care delivers 8-15% cost reduction for high-cost, concentrated, older employer populations with strong enrollment. For other groups, the per-employee costs often exceed realized savings.

Before contracting, require prospective modeling based on your specific claims data. Demand the provider project enrollment rates by location and age band—not organization-wide averages. Negotiate clawback terms so you don't subsidize the provider's growth in underperforming markets. Commit minimum 24 months to allow the model to mature, but not before validating Year 1 baseline and enrollment against the provider's projections.

The data supports value-based primary care for the right employer profile. Most employers aren't that profile yet.