I realized now that you said that you were 38 in 1990. So, now in 2016, you should be age 64. Therefore, I think your question is why the disability benefit turned into social security retirement income. I will address to each phrase in your posting as follows.
1) The social security disability turns to social security retirement income when the person turns full retirement age. The amount, however, should not change.
2) In most cases, you will continue to receive disability benefits as long as you are disabled. However, there are certain circumstances that may change your continuing eligibility for disability benefits. For example,
- your health may improve to the point where you are no longer disabled; or
- like many people, you would like to go back to work rather than depend on your disability benefits.
The law requires that we review your case from time to time to verify that you are still disabled. We tell you if it is time to review your case, and we also keep you informed about your benefit status. You also should be aware that you are responsible for letting us know if your health improves or you go back to work.
3) A criminal conviction can cause the benefit to suspend in certain situation.
4) As to why your Aetna LTD lasted 7 years, we can only second guess. If it was an employer provided plan, it is the contract your employer obtained. Most of the times, the work long-term disability plan will push us to apply for social security disability to move us to social security disability so that we can be off the employee plan if we are no longer an employee in the company and in the insurance pool.
5) Two things can cause us to decide that you are no longer disabled and to stop your benefits.
Your disability benefits will stop if you work at a level we consider "substantial."
In 2016, average earnings of $1,130 or more per month ($1,820 or more per month if you are blind) are usually considered substantial.
Your disability benefits also will stop if we decide that your medical condition has improved to the point that you are no longer disabled.