Not filing tax returns is a statutory offence, but paying your fine/s for that doesn't get you off the hook. You also of course have to pay the tax due for the period/s in question - plus you're in for "additional tax" of twice that again. That's effectively four payments you make to the State's coffers (plus any interest due).
And, the Tax Court held recently, your Constitutional protections against "double jeopardy" don't apply here. Better get those returns in (or get extensions) - right now!