Long Term Disability

That’s correct.

FICA taxes are only withheld for the first six calendar months after the employee has stopped performing services for the employer. 

After that, disability payments will be exempt from FICA withholding.   

Since your wife has been on long-term disability for 2-½ years, no FICA withholding is taking place.

Thank you so much for that information. I have one more question when I file our taxes do we add my wife's income on the W-2 from her disability payments as normal?

Regards

Perhaps!  If you have a W-2 for your wife's disability payments you would enter that as normal.