Max was born on the 29th of January, 1932, in Lodi, California. He grew up in Oakridge, Oregon after his family moved there and while he did attend school there, he dropped out before graduating high school in 1950 and enlisted in the US Army. Very little is known about his seventeen years of service prior to being deployed to the Republic of Vietnam but it is known that Max was assigned to Company A, 4th Battalion, 9th Infantry, 25th Infantry Division and it was his actions on the 26th of February, 1967, as the company First Sergeant that would earn him the Medal of Honor. The citation reads:

For conspicuous gallantry and intrepidity at the risk of his life above and beyond the call of duty. 1st Sgt. Yabes distinguished himself with Company A, which was providing security for a land clearing operation. Early in the morning the company suddenly came under intense automatic weapons and mortar fire followed by a battalion sized assault from 3 sides. Penetrating the defensive perimeter the enemy advanced on the company command post bunker. The command post received increasingly heavy fire and was in danger of being overwhelmed. When several enemy grenades landed within the command post, 1st Sgt. Yabes shouted a warning and used his body as a shield to protect others in the bunker. Although painfully wounded by numerous grenade fragments, and despite the vicious enemy fire on the bunker, he remained there to provide covering fire and enable the others in the command group to relocate. When the command group had reached a new position, 1st Sgt. Yabes moved through a withering hail of enemy fire to another bunker 50 meters away. There he secured a grenade launcher from a fallen comrade and fired point blank into the attacking Viet Cong stopping further penetration of the perimeter. Noting 2 wounded men helpless in the fire swept area, he moved them to a safer position where they could be given medical treatment. He resumed his accurate and effective fire killing several enemy soldiers and forcing others to withdraw from the vicinity of the command post. As the battle continued, he observed an enemy machinegun within the perimeter which threatened the whole position. On his own, he dashed across the exposed area, assaulted the machinegun, killed the crew, destroyed the weapon, and fell mortally wounded. 1st Sgt. Yabes' valiant and selfless actions saved the lives of many of his fellow soldiers and inspired his comrades to effectively repel the enemy assault. His indomitable fighting spirit, extraordinary courage and intrepidity at the cost of his life are in the highest military traditions and reflect great credit upon himself and the Armed Forces of his country.

During this attack, twenty-four American soldiers had been killed, as well as over 113 Vietcong soldiers. A little over a year and a half later, in October of 1968, Max's wife and children received his Medal of Honor from Stanley Resor, the Secretary of the Army, in a ceremony at the Pentagon. In addition to the many individuals, dozens of Oakridge businesses and organizations donated their time, money, labor, and supplies in order to have a memorial built for Max. Tim Outman was the sculpture that was hired to create the memorial, which features a fountain and a bust of Max, along with a flag pole and engravings of his actions. This memorial stands in the Greenwaters Park in Oakridge and in El Paso, Texas, an avenue was named in his honor. Maximo Yabes is buried in the Fort Logan National Cemetery in Denver, Colorado: Section R, Site 369. His name appears on Panel 15E, Line 102 of the Vietnam Veterans Memorial Wall in Washington DC.