The U.S. Golf Association and the Royal and Ancient Golf Club issued a statement Tuesday that Rule 14-1b will bar players from putting the shaft of long putters against their bodies while making a stroke.
Long putters can still be used but must be swung without anchoring.
USGA President Glen D. Nager said the change is "necessary to preserve one of the important traditions and challenge of the game -- that a player freely swing the entire club."
The rule, proposed last November, won't take effect until January 2016 to allow for golf's usual four-year wait to implement changes in the rule book.
The new rule will read:
"In making a stroke, the player must not anchor the club, either 'directly' or by use of an 'anchor point.'
"Note 1: The club is anchored 'directly' when the player intentionally holds the club or a gripping hand in contact with any part of his body, except that the player may hold the club or a gripping hand against a hand or forearm.
"Note 2: An 'anchor point' exists when the player intentionally holds a forearm in contact with any part of his body to establish a gripping hand as a stable point around which the other hand may swing the club."