Accident-only
Covers unexpected injuries such as fractures, bite wounds and swallowed objects. It generally excludes illness, so conditions like infections, allergies and cancer would not be reimbursed.
Accident-and-illness
Covers both injuries and covered illnesses, which is what most people mean by comprehensive pet insurance. It is typically the higher-cost option.
How to choose
Accident-only can fit a tight budget, or a young, healthy pet where you mainly want protection from emergencies. If you want protection against costly illnesses, a broader plan is the better fit. Also consider adding wellness coverage only if the extra premium is less than or close to what you would spend on routine care.
Sources and further reading
This guide explains general industry practice. For the terms that apply to you, rely on the policy documents from each insurer you consider and on the consumer resources published by your state insurance department.