That's not a matter of law; it's a matter of the terms of your former employer's disability policy. Here are some of the possibilities:
1. If you were laid off before you became disabled, then there are no circumstances I can begin to imagine in which you would be eligible to receive benefits under your employer's policy. Every plan I have ever seen or heard of requires that you be employed at the time you became disabled before you can receive benefits.
2. if you were employed at the time you became disabled, but have not yet applied for disability benefits, you have almost certainly waited too long. You can call your former employer and ask, but I seriously doubt that the plan allows for you to claim benefits two years after the fact.
3. If you were employed at the time of your disability and you did apply for benefits and were turned down, you are almost certainly past the SOL to appeal. Again, you can call your former employer and ask, but it's exceedingly unlikely.
4. If you were employed at the time of your disability, applied for benefits and received them, the terms of the policy will dictate how long they will continue.