Rapper OG Maco, best known for his 2014 viral smash "U Guessed It," was rushed to the hospital Thursday morning with a gunshot wound to the head, TMZ Hip Hop can confirm.

Police sources say they responded to a 911 call in the Los Angeles area at 10 AM after a neighbor heard a gun go off inside a home.

It's unclear what transpired leading up to the shot -- but all signs point to an apparent suicide attempt.

We're told the ATL-born Maco was found unresponsive and was rushed to a local hospital and immediately into surgery. A firearm was also retrieved at the scene.

Maco's manager, Poppa Percccc, tells TMZ Hip Hop his longtime friend is not deceased, but needs urgent prayers from all his friends, fans, supporters and associates.

Maco was one of the legendary QC Records' first breakout stars in the mid-2010s. We're told he has plenty of fresh new music in the vault as well.

This story is developing ... get well soon. 🙏🏾