Do I need a lawyer to get disability retirement benefits?

Disability retirement benefits are two different things. Both are offered by the SSA, but this is where the similarities end. 

• Disability benefits, or SSDI, is offered to those who become unable to work either permanently or for a period of two or more years. To collect such benefits, you must prove your illness is severe, either by demonstrating that you have a disability listed in the SSA blue book of impairments or by demonstrating that your problem is as serious as those that are listed.
• SSA retirement benefits, on the other hand, are offered to all who have reached retirement age and who have paid into the system (or had a spouse that paid in) so they qualify

You do not need to have a lawyer to collect retirement benefits, since these are offered to all eligible individuals. You may, however, need a lawyer to get SSDI benefits. SSDI benefits are offered only to those who qualify, and the SSA makes the application process difficult in order to weed out those who are making fraudulent claims. 

A lawyer can help you to properly complete all the paperwork and to collect the evidence you need to convince the SSA that you are in fact sufficiently disabled so as to be entitled to benefits.