Social Security disability insurance, or SSDI functions as an insurer of "last resort" for people who suffer from a disabling condition that prevents them from working. In most cases, SSDI only covers the most severe of disabling conditions. Temporary total disability and permanent partial disability describe the two categories of conditions that qualify for Social Security disability benefits. The differences between the two categories have to do with the length and severity of a condition.
Eligibility for Social Security disability benefits hinges on whether a person can perform any type of work task for prolonged periods of time. In the case of temporary total and permanent partial disabilities, reviewers also consider a person's previous line of work when determining the effects of a disability. Disability determinations involve a review process that examines the effects of a person's condition on his ability to earn a living. Disability review boards must consider the severity of a physical condition and determine whether it causes impairment significant enough to warrant financial assistance through disability benefits. In effect, disability determinations involve both a medical and an economic evaluation of a person's physical status.
Partial vs. Total Disability
One of the differences between temporary total disability versus partial permanent disability has to do with whether a person can perform any form of gainful employment at all. Someone with a partial disability performs at a reduced capacity compared to before a disability existed. In other words, the condition prevents him from working in his usual line of work, but he can still perform within other work roles. Someone with a total disability has lost most, if not all, ability to perform in any type of work role as well as in his previous line of work.
Temporary vs. Permanent Disability
When considering a disability claim, Social Security reviewers may label a condition as temporary, even when a permanent disability exists. Social Security views a disabling condition in terms of the potential for recovery and requires claimants to undergo periodic physical examinations to determine if a condition has improved. In some cases, the difference between a temporary total disability and a permanent partial disability becomes evident when a person receives an impairment rating evaluation. According to the National Archives & Records Administration, an impairment rating evaluation occurs after a person receives a temporary total disability rating and has received benefits for 104 weeks. Based on a physician's evaluation, someone who shows little-to-no physical recovery may go from a temporary total rating to a permanent partial disability rating in cases where a person can still perform at 50 percent of their prior work capacity.
Differences in Benefit Entitlements
The differences between temporary total disabilities and permanent partial disabilities play a role in how Social Security determines a person's benefit entitlement amount. People with a permanent partial disability rating can receive benefits for up to 500 weeks as of the date of an injury, according to the National Archives & Records Administration. People with a temporary total disability rating can receive benefits on an ongoing basis that begin as of the date of their last day at work. In general, benefit amounts equal a percentage of the difference between the wages a person earned in their previous line-of-work and her current wage-earning capacity. Percentage amounts fall somewhere between 66-2/3 to 75 percent of the difference in wages.