Medical Underwriting Explained: What Mid-Size Employers Need to Know When Carriers Review Your Workforce

If your company has 20 to 250 employees, there is a good chance your health plan goes through some form of medical underwriting every year. This is the process where a carrier looks at your workforce's health claims history, demographics, and risk profile to decide what your renewal rate will be -- or whether they will offer coverage at all.

For many employers, underwriting feels like a black box. You send in your census data, wait a few weeks, and get back a number that either makes you breathe easier or sends you scrambling for alternatives. Understanding how this process actually works gives you leverage. It helps you ask better questions, negotiate smarter, and build a benefits strategy that keeps costs predictable year over year.

This guide breaks down everything mid-size employers need to know about medical underwriting -- from how carriers evaluate your group, to what triggers rate increases, to the strategies that give you more control over your costs.

What Is Medical Underwriting and Why Does It Matter?

Medical underwriting is the process a carrier uses to evaluate the risk of covering a group of employees. The carrier looks at your workforce's health profile and uses that information to calculate how much to charge for coverage. This is different from individual underwriting, which evaluates one person at a time. Group underwriting looks at the entire population of employees and their dependents.

For fully covered plans, underwriting determines your premium rate. For level-funded and self-funded arrangements, it influences your expected claims liability, stop-loss premiums, and administrative fees. Either way, the underwriting process directly determines what you pay for benefits every year.

The Difference Between Community Rating and Experience Rating

Small groups (typically under 50 employees in most states) are subject to community rating under the Affordable Care Act. This means the carrier cannot use your group's specific claims history to set rates. Instead, rates are based on broad demographic factors like age, location, and tobacco use.

Once your group crosses the 50-employee threshold, most states allow carriers to use experience rating. This is where your actual claims data starts driving your renewal rate. If your group had a healthy year, you may get a favorable renewal. If you had several high-cost claims, your rate could increase significantly. This shift from community rating to experience rating is one of the most important transitions a growing company goes through.

What Carriers Look at During Underwriting

Understanding the specific factors carriers evaluate helps you prepare for the process and take steps to improve your risk profile. Here are the major components of group medical underwriting.

Claims History and Loss Ratio

Your claims history from the past 12 to 24 months is the single most important factor. Carriers look at your loss ratio, which is the percentage of premiums paid out in claims. A loss ratio of 80% means for every dollar you paid in premiums, 80 cents went to paying claims. A loss ratio above 85% to 90% often triggers a significant rate increase at renewal.

Carriers also look at the trend of your claims. Are they increasing year over year? Are there specific high-cost claimants driving the numbers? This granular analysis determines whether your renewal will be favorable or painful.

Group Demographics

The age and gender distribution of your workforce matters. An older workforce statistically generates higher claims. Carriers use actuarial tables to calculate expected costs based on your group's demographic profile. A company with an average employee age of 52 will face higher base rates than one with an average age of 35, all else being equal.

Industry and Occupation

Some industries carry higher risk profiles. Construction, manufacturing, and transportation workers may face higher rates due to occupational hazards. Office-based employers in professional services or technology typically get more favorable underwriting treatment. Carriers maintain industry classification codes and associated risk factors for each.

Geographic Location

Healthcare costs vary dramatically by region. A group in New York City will face different rate structures than one in rural Texas. Carriers factor in local provider costs, hospital charges, and prescription drug pricing for your area. Multi-state employers may see different rates for employees in different locations.

Plan Design and Network

The richness of your plan design affects underwriting outcomes. Higher deductible plans with narrower networks cost less to underwrite because employees share more of the financial responsibility and care is channeled to lower-cost providers. Plans with low deductibles, broad PPO networks, and rich prescription coverage carry higher expected claims and therefore higher premiums.

Participation Rate

Carriers want to see high participation rates in your plan. When only a small percentage of employees enroll, the risk pool becomes less predictable. Most carriers require at least 70% to 75% participation to offer their best rates. Low participation can signal adverse selection, where only the employees who expect to use benefits heavily are enrolling.

How Underwriting Differs by Funding Model

The type of health plan funding you choose significantly affects how underwriting works and how much control you have over the process.

Fully Covered Plans

With fully covered plans, the carrier takes on all the claims risk. Underwriting is done annually at renewal, and the carrier sets a fixed premium rate. You have limited visibility into the actual claims data driving your rate. Many carriers will share a summary loss ratio, but detailed claims information is often difficult to obtain.

For groups under 50 employees, ACA community rating rules limit how much carriers can vary rates. For groups over 50, experience rating allows carriers to adjust rates based on your specific claims history. This is why growing from 49 to 51 employees can actually result in either a significant rate decrease or increase, depending on your group's health profile.

Level-Funded Plans

Level-funded arrangements offer a middle ground. You pay a fixed monthly amount that covers expected claims, stop-loss premiums, and administrative costs. Medical underwriting is more detailed because the administrator needs to set accurate expected claims levels. However, if your group's actual claims come in lower than expected, you may receive a refund of the surplus.

Level-funded plans typically require medical questionnaires for all enrollees and may even request prescription drug history. The underwriting is more thorough, but the payoff is potentially lower costs and the chance to benefit from your group's good health. For mid-size employers with relatively healthy workforces, level-funded plans often deliver 10% to 20% savings compared to fully covered options. Learn more about how these plans compare in our guide to MEWA vs. level-funded health plans.

Self-Funded Plans

Self-funded (or self-covered) plans give you the most control. Your company pays claims directly and purchases stop-loss coverage to protect against catastrophic costs. Underwriting focuses primarily on the stop-loss policy -- the carrier evaluates your risk to determine the specific and aggregate stop-loss deductibles and premiums.

Self-funded plans provide full claims transparency. You see every dollar spent, which means you can make data-driven decisions about plan design, network selection, and cost management strategies. For mid-size employers with 100 or more employees, self-funding is increasingly common because it removes the carrier's profit margin from your premium costs. Understanding how your costs compare to industry benchmarks is essential when considering self-funding.

What Triggers a Bad Underwriting Outcome

Several factors can lead to unfavorable underwriting results, including higher premiums, coverage exclusions, or carrier denials. Knowing these triggers helps you take proactive steps to manage your group's risk profile.

High-Cost Claimants

A single employee or dependent with a chronic condition, cancer diagnosis, organ transplant, or specialty drug prescription can dramatically skew your claims data. One person generating $200,000 to $500,000 in annual claims can push your entire group's loss ratio above 100%, triggering double-digit rate increases.

This does not mean you should try to identify or penalize high-cost individuals. That would violate HIPAA and employment law. Instead, you manage this risk through plan design -- implementing stop-loss protection, tiered networks, and pharmacy benefit management strategies that control costs without reducing access to care.

Carrier Denials and Market Exits

In some cases, a carrier may decline to renew your group entirely. This is more common with level-funded and self-funded arrangements where the carrier has more flexibility. If your group has had multiple years of high claims, the carrier may decide the risk is not worth underwriting at any price.

When this happens, you need to be prepared to move quickly. Having a relationship with a broker or benefits consultant who works with multiple carriers and funding models is essential. The worst position to be in is having 60 days until your plan expires and no alternatives lined up. Employers who have dealt with high-risk employees in their health plan know this challenge well.

Industry Risk Factors

Certain industries face inherently higher underwriting scrutiny. If you operate in construction, roofing, landscaping, or other physically demanding fields, carriers may apply industry surcharges or require additional documentation about your safety programs and workers' compensation history.

Strategies to Improve Your Underwriting Position

You cannot control everything about your group's health, but there are concrete steps that improve how carriers evaluate your risk and the rates they offer.

Request and Analyze Your Claims Data

The most important step is getting access to your own data. Ask your carrier or broker for a monthly claims report that includes total claims paid, large claimant summary (de-identified), loss ratio, and trend analysis. If your broker cannot or will not provide this, that is a red flag. Your claims data is yours, and you have the right to see it.

With this data in hand, you can identify patterns. Are a few individuals driving the majority of costs? Are there specific categories of claims (pharmacy, specialty drugs, out-of-network) that are disproportionately high? This analysis is the foundation for every cost management strategy.

Implement Wellness and Preventive Programs

Wellness programs do not produce overnight results, but over two to three years they can measurably reduce claims costs. Programs that focus on chronic disease management (diabetes, hypertension, musculoskeletal issues) tend to have the highest ROI. The key is making participation easy and incentivizing engagement through premium differentials or HSA contributions.

Optimize Plan Design

Small changes in plan design can significantly affect underwriting outcomes. Moving from a $500 deductible to a $1,500 deductible, adding a pharmacy formulary tier, or implementing a narrow network option can reduce expected claims by 8% to 15%. The key is balancing cost savings with employee satisfaction -- a plan that saves money but drives away talent is not a win.

Explore Alternative Funding Models

If you have been fully covered and are seeing consistent double-digit renewals, it may be time to explore level-funded or self-funded options. These arrangements allow you to benefit from good claims experience rather than subsidizing the carrier's broader risk pool. A mid-size employer with 75 to 200 employees and a healthy workforce can often save 10% to 25% by switching to an alternative funding model.

Market Your Plan Annually

Never accept a renewal without shopping it. Even if you stay with your current carrier, having competing quotes gives you negotiating leverage. Carriers know when an employer has alternatives, and they adjust their pricing accordingly. The employers who see the lowest long-term cost trends are the ones who market their plan every year, regardless of what the renewal looks like.

The Role of Your Broker in the Underwriting Process

Your benefits broker or consultant plays a critical role in how underwriting goes. A skilled broker can present your group's data in the most favorable light, negotiate with carriers on your behalf, and identify alternative solutions when the initial underwriting comes back unfavorable.

Here is what a good broker should be doing during the underwriting and renewal process:

• Submitting your census and claims data to at least three to five carriers for competing quotes
• Reviewing the carrier's underwriting assumptions and challenging any that seem unreasonable
• Presenting multiple funding model options (fully covered, level-funded, self-funded, ICHRA)
• Providing a clear breakdown of where your premium dollars go (claims, admin, profit margin, commissions)
• Recommending plan design changes that improve your underwriting position without degrading coverage

If your broker is simply passing along the renewal number without analysis or alternatives, you are leaving money on the table. The difference between a passive and proactive broker can easily be 10% to 20% of your total benefits spend.

Frequently Asked Questions

What is the difference between medical underwriting for small groups and large groups?

Small groups (under 50 employees in most states) are subject to ACA community rating, which means carriers cannot use your specific claims history to set rates. Large groups (50 or more employees) are subject to experience rating, where your actual claims data directly influences your premium. This means large group employers have both more risk exposure and more opportunity to control costs through plan design and claims management.

Can a carrier deny coverage to my group based on underwriting?

For fully covered small group plans, ACA rules require carriers to offer coverage to any eligible group regardless of health status (guaranteed issue). For large group fully covered plans, carriers have more flexibility and can decline to offer coverage or set rates that effectively price you out. Level-funded and self-funded arrangements have no guaranteed issue requirement, so carriers can decline to underwrite your stop-loss or set prohibitively high deductibles.

How far back do carriers look at claims history?

Most carriers review 12 to 24 months of claims data during underwriting. Some may look at up to 36 months for larger groups or when evaluating self-funded stop-loss applications. The most recent 12 months typically carry the most weight in the analysis. If you had a particularly bad claims year two years ago but a clean year since, carriers will generally weigh the recent improvement favorably.

What is a loss ratio and what does mine mean?

Your loss ratio is the percentage of premiums that go toward paying claims. A loss ratio of 75% means that for every dollar you pay in premiums, 75 cents is used to pay claims and 25 cents covers the carrier's administrative costs, reserves, and profit. For mid-size employers, a loss ratio between 70% and 85% is generally considered normal. Above 85% to 90%, you should expect a significant renewal increase. Below 65%, you may be a good candidate for level-funded or self-funded arrangements where you could capture those savings directly.

How can I improve my group's underwriting profile before renewal?

Start by requesting your full claims data at least 90 days before your renewal date. Identify any plan design changes that could reduce expected claims (higher deductibles, pharmacy management, narrow networks). Implement or expand wellness programs that target your highest-cost conditions. Consider alternative funding models if your current arrangement is not rewarding your group's health. Most importantly, work with a broker who will market your plan to multiple carriers and negotiate aggressively on your behalf.

Does switching carriers reset my underwriting history?

Switching carriers does not erase your claims history. New carriers will request your prior claims data as part of their underwriting process. However, a new carrier may evaluate your data differently, apply different trend factors, or offer more competitive administrative fees. Sometimes a carrier change results in significantly better rates not because your risk profile changed, but because the new carrier prices your specific demographic and industry more favorably.

What should I do if my carrier denies renewal or quotes an unaffordable rate?

First, do not panic. This happens more often than you think, especially after a year with high claims. Have your broker submit to every available carrier and explore all funding models (fully covered, level-funded, self-funded, PEO, ICHRA). Sometimes the best solution is a combination -- for example, a two-tier strategy with different plans for different employee populations. The key is starting this process early so you have time to evaluate all options before your current coverage expires.

References

1. Kaiser Family Foundation. (2025). Employer Health Benefits Survey. kff.org
2. Society for Human Resource Management. (2025). Managing Health Care Costs. shrm.org
3. Centers for Medicare and Medicaid Services. (2025). Market Rating Reforms. cms.gov
4. National Association of Health Underwriters. (2025). Group Medical Underwriting Guidelines. nahu.org
5. Department of Labor. (2025). Reporting and Disclosure Guide for Employee Benefit Plans. dol.gov