16 percent of Americans alive at age 55 are on Medicare before age 65, report finds.

About one-quarter of disabled workers under age 65 who start receiving Social Security disability income are uninsured during the two years they must wait to obtain Medicare benefits, according to a recent study published on the Health Affairs Web site.

Employers cover about half of those in the waiting period, say researchers Pamela Farley Short from Penn State University and France Weaver from the Swiss Health Observatory in Neuchatel, Switzerland.

Using longitudinal data from the University of Michigan’s Health and Retirement Study, Short and Weaver evaluated a randomly selected, nationally representative sample of Americans born during the period 1936-1941.

According to the study, by tracking each individual’s health insurance from age 55 to age 65, Short and Weaver found that fully half of the people who lacked insurance during the Medicare waiting period were uninsured before they began receiving SSDI.

Moreover, the loss of employer insurance accounted for only 36 percent of those uninsured in the waiting period. Relatively few people (12 percent) who were initially covered by employers became uninsured during the waiting period. Three-quarters retained employer insurance through spouses or former employers after they were no longer able to work, the study says.

“Our findings suggest that eliminating the waiting period would indeed be the best way to cover people with disabilities who are uninsured without Medicare,” said Short, a professor of health policy and administration at PSU, as stated in the Web site.

Congress might consider eliminating the waiting period only for disabled workers without access to employer-sponsored insurance, Short and Weaver advised, saying that from the government’s perspective, even with generous subsidies to new SSDI recipients to defray the cost of employer premiums, premium subsidies would likely cost less than enrolling people with severe disabilities in Medicare.

Short and Weaver suggested that because premiums are based on claims averaged over all enrollees, and the average claims of people with disabilities are likely to be well above the employer average, the government could save money by paying premiums to employers instead of claims under Medicare.

The study authors found that just over 16 percent of Americans alive at age 55 were on Medicare before age 65 and therefore had to negotiate the waiting period.