Honest, plain-English answers to the decisions that actually matter.
You pay a monthly premium; when your pet has a covered accident or illness, you pay the vet and the insurer reimburses you a percentage (commonly 70–90%) after your deductible, up to an annual limit. Pre-existing conditions and routine care are not covered by standard plans.
It is worth it mainly as protection against rare, large bills you could not easily pay in cash. For a healthy pet you may pay somewhat more in premiums over a lifetime than you claim back, but one major surgery or cancer diagnosis can return years of premiums at once.