Why Have Long Term Disability Insurance? 
Social Security Disability Insurance may help some , but not anywhere close to your annual compensation . Your employer may have short term disability insurance inside the companys employee group benefit plan . That can help , but only as a supplement . Most Americans have 90 days in cash reserves for household expenses . And the odds of experiencing a disability over your working life time are surprisingly high . The average time spent on full disability is 30 months . Depending on your gender , age , smoking status and health condition , you may need to pay 5 to 8 % of your compensation to purchase ling term disability insurance . 