Not all health insurance plans are of equal value to enrollees. Covered benefits, deductibles, and copayments all vary, which in turn determine the share of health care expenses reimbursed by the plan and that paid out-of-pocket by the patient. This project will analyze previously unavailable data on the proportion of medical bills that would be expected to be paid by the insurer-the financial protection provided by the health plan-to explore how variations among states and between small and large firms influence their likelihood of offering coverage and workers' likelihood of participating in a plan. It will also calculate the change in financial protection provided by benefit plans from 2001 to 2003, as firms continue to shift higher insurance costs to employees. The researchers will estimate the percentage of Americans who are insured but nonetheless 'underinsured'-that is, they have out-of-pocket health care costs exceeding a reasonable percentage of their income. Study results, which will be disseminated as a chartbook, will help state and federal policy leaders design future health coverage strategies. http://www.hret.org