The Affordable Care Act (ACA) requires most individual and employer plans to cover preventive services at 100% with no cost-sharing for patients. So why do medical practices still see denials when billing preventive services to ACA plans? Much like any other service, coverage of preventive care doesn’t necessarily guarantee payment. 

To ensure payment for preventive services, practices must still bill these services correctly and follow each payer’s rules. Small errors in diagnosis coding or modifiers, for example, may cause a preventive health denial of service. In addition, non-ACA plans are not required to cover preventive services. And many either exclude them or apply cost-sharing — making preventive visits a frequent source of denials and patient balances.

It’s important for practices to bill preventive care, including Medicare Annual Wellness Visits, correctly as failing to do so can impact revenue and patient trust and engagement. When a preventive health denial of service occurs, balances shift to patients who aren’t expecting to receive a bill. As a result, patient trust drops, portal messages and phone calls expressing dissatisfaction increase, and practices often see more bad debt. 

In addition, when practices miscode or misbill preventive care, they compromise quality and value-based reporting. That’s because preventive services feed into HEDIS measures, quality dashboards, and value-based contract benchmarks.

When quality metrics aren’t accurate, neither are shared savings, bonuses, or penalties. In this article, we’ll provide simple strategies to avoid denials when billing preventive services so practices can stay focused on providing high-quality patient care.

A preventive health denial of service can occur for a variety of reasons. Here are some of the most common reasons for denials and what practices can do to mitigate risk.

When a claim includes a problem-oriented diagnosis instead of a preventive ICD-10-CM Z code, payers may automatically reclassify the visit as diagnostic, making it subject to deductible/coinsurance — or they may deny it outright.

In the absence of clear documentation separating a preventive health service from a separately billable E/M service to address a separate concern, payers may deny one line item or the entire claim. When providers address a chronic or acute issue during a preventive visit, they may be able to bill a separate E/M with modifier -25 but only when documentation clearly supports two distinct services. 

Denials for improperly billing preventive care with problem-oriented E/M services can affect all patients. However, one recent study found they may be more likely to occur when billing preventive services for patients with greater social needs. More specifically, the study found denials for diabetes screening, depression screening, and contraceptive care services are higher for: 

This could be because patients with higher social needs may also be more likely to have multiple chronic conditions, unmet behavioral health needs, medication access issues, unstable housing, or food insecurity that could negatively affect their health. And a preventive health denial of service can occur when providers address multiple separate issues during a preventive visit, but don’t follow coding and billing rules.

For example, a mammogram may be covered but only once a year. And billing for this service even a day early can cause a denial. Payers often deny the service as not medically necessary even though it is clinically reasonable. 

In the absence of active coverage, a preventive health denial of service will occur. Again, patients with greater social needs may be more likely to experience these denials due to Medicaid churn, plan switching, retroactive terminations, and gaps between eligibility periods. However, inactive coverage may become more problematic for all patients as federal Medicaid changes take effect over the next year.

Looking for high-impact steps to reduce denials of preventive services? Consider the following:

And use this comprehensive checklist.

Tighter payer rules, more complex documentation standards, and evolving coverage policies are all likely to drive an increase in claim denial rates throughout 2026. And practices that apply rigorous, automated checks to preventive claims — much like they do with more costly services — are more likely to protect their revenue.