Is there a need for disability income insurance? If Yes, why? If No, why?

Well, assuming you are 30 and become permanently disabled, you will need about say $3000/month for another say 30 years (or more), which works out to be about $1m. Do you have this money in your investment? You probably are covered for $1m for TPD, but TPD is only claimable when a person almost become a vegetable (totally cannot work at all, or loss 3 ADLs), whereas disability income pays as long as the person is unable to work in his current profession, or profession suited based on his education and experience. The premium is usually only about 1% of a person's income, highly affordable. IF you are still not financially independent, then your income is your most critical source of wealth.

I have been thinking about this recently too.