If you are fired while disabled, this may be a violation of the Americans with Disabilites Act. Your employer is not going to admit your disability is the reason for the firing. You can file a complaint with the Equal Employment Opportunity Commission (EEOC) in your state and ask them to investigate it for you. You may also want to talk to a Wrongful Discharge or Employment Attorney in your state.
THESE COMMENTS ARE NOT LEGAL ADVICE. They are provided for informational purposes only. Actual legal advice can only be provided after consultation by an attorney licensed in your jurisdiction. Answering this question does not create an attorney-client relationship or otherwise require further consultation.
The Family and Medical Leave Act (FMLA) applies to companies with at least 50 employees. If you were on FMLA leave, you must be given 12 weeks to return to work, minus any FMLA days you took during the year. After that, you can be terminated if the company needs to hire someone to do your job. You need to speak with an attorney or someone from the NY State Division of Human Rights to be sure.