Which type of medical expense plan provides first-dollar coverage but has low limits for catastrophic coverage?

Base plans are designed to provide initial coverage for medical expenses without requiring a deductible, which is why they are often described as offering first-dollar coverage. This means that as soon as a qualifying medical expense is incurred, the plan begins to pay benefits, making healthcare access more immediate for policyholders.

However, it's important to note that base plans typically have lower limits when it comes to catastrophic coverage. This means that while they may cover routine medical expenses well, they may not provide sufficient support for significant medical events, such as serious illnesses or major surgeries, which can lead to substantial bills.

In contrast, supplemental plans tend to address specific gaps by adding coverage to primary insurance, hence they do not operate on first-dollar coverage; comprehensive plans usually cover a wide range of health services, including catastrophic coverage; and catastrophic plans are specifically designed to cover high-cost medical events but generally do not offer first-dollar coverage. Thus, the characteristics of base plans uniquely match the description in the question.