There had been speculation that the world number one would be disqualified from the Masters in Augusta after he took a drop two feet away from where he originally took a shot, which ended up in the water on the 15th hole yesterday.
The 37-year-old tweeted: "I didn't know I had taken an incorrect drop prior to signing my scorecard. Subsequently, I met with the Masters Committee Saturday morning and was advised they had reviewed the incident prior to the completion of my round.
"Their initial determination was that there was no violation, but they had additional concerns based on my post-round interview.
"After discussing the situation this morning, I was assessed a two-shot penalty. I understand and respect the Committees' decision."
The penalty leaves Woods five shots behind leader Jason Day ahead of today's play.