It probably depends by state. I was required to reveal I was a felon while on parole. Once I was off parole I no longer had this requirement but... I was constantly faced with the question on my job applications. My approach was always not to lie and only answer the questions asked, adding "will discuss during interview if needed". Twice I made it to the interview only to be rejected after the nature of my crimes were revealed. On two separate occasions I was offered employment, started work, and was later let go because of my felony conviction.