Health insurance companies are increasingly offering coverage for services such as maternity care, dental care and prescription drugs as well as coverage for preventive care and home care.

But the coverage varies widely, according to a new study.

The study by the nonpartisan Kaiser Family Foundation found that some of the top health insurance plans are not offering comprehensive coverage at all, while others offer only partial coverage.

While health insurance coverage varies significantly across states, insurers are often not sharing their data with consumers, the foundation said.

For example, the health insurance company Aetna is offering coverage only for birth control.

In other cases, insurers can’t provide comprehensive coverage for cancer screenings or for dental care.

The Affordable Care Act requires that insurance companies provide coverage for most essential health services, but some companies are refusing to provide coverage that does not include coverage for maternity care or other preventive care.

Aetnam and Humana have denied that they are offering incomplete coverage, according the foundation.

The Kaiser Family Affiliates said that the data should be viewed with caution because insurers typically only provide coverage to people who sign up for the plans.

For instance, some plans do not cover prescription drugs or emergency room visits.