Romo had been contemplating having a plate inserted into his collarbone as late as last week. However, after undergoing a CT scan on Wednesday, he opted for the Mumford procedure, in which the distal part of the clavicle is shaved down to release potential pressure against the shoulder.
The time frame for recovery is six to eight weeks. Romo is expected to be able to participate in organized team activities in May and June.
Romo broke his collarbone twice in 2015. The first time came Sept. 20 against the Philadelphia Eagles, and he missed seven games. In his second game back, Romo suffered a hairline fracture in a Thanksgiving Day loss to the Carolina Panthers, and he didn't play the rest of the season.
The Cowboys went 3-1 in Romo's four starts. He finished the season with five touchdown passes and seven interceptions.
Romo, who turns 36 in April, has broken his collarbone three times since 2010. This will be the third surgery of his career; he had two back surgeries in 2013.
At last week's NFL combine, owner and general manager Jerry Jones said the Cowboys will make their decisions regarding the draft with the idea Romo will be the team's quarterback for the next four to five years. Holding the fourth pick in this year's draft, the Cowboys have met with all of the top quarterbacks available and likely will bring some to Valley Ranch for predraft visits.