Am I cleared

Last spring I received the information to complete for background investigation. I had my in person interview and was waiting to see what was next. Today I received a letter saying that the background investigation was successfully closed and no further action was required of me. It also stated that notice of investigation will be retained in my files. I guess my question is am I cleared or what?

You didn’t say if the investigation was for a security clearance or for a government position. If for a clearance you still need to get a security briefing and sign a SF-312 non-disclosure agreement. If not for a clearance then no further action is required.