PhD student apply for NIW

Hi,
I am a PhD student in mechanical engineering. Can I apply for NIW now? Is it better to wait until I get my PhD degree? Can someone answer me?

to aileen:

You should be able to apply for NIW without a PhD degree if you have another advanced degree. Do you have a Master's degree?

to Armando:

OK thanks.
And yes, I have a Master's degree.