Hi. Was told by former CPA and filed this way through him for years. He states that because I was a fed civilian employee, I did not have to file NY state taxes and could get away with only filing NJ state taxes since that is where I live. My gut tells me he is wrong... but he comes highly recommended and I'd be shocked if he was doing something unethical or unknowingly. Please advise. Thanks.

CK1:

I am a federal employee when I am not wearing the uniform, and, except for those cases where federal employees work on a federal reservation of some type (like a military base), state tax laws apply to federal employees just like they do everyone else.

Hence, In my opinion, you do owe NY state income taxes if you worked in NY state.

A phone call or e-mail to the NY state taxing authority can confirm or deny this, and I recommend that you get that from them as the final authoritatiuve source.