The shooting happened outside their home on Sturtevant Hill Road around 1:30 p.m..
The man suffered a single gunshot wound, but was conscious when police arrived. He spoke with officers before being taken to a nearby hospital.
"We're taking the time that we need to make sure that we investigate it properly," Kennebec County Sheriff Ken Mason said. "It's not a homicide, [it's] elevated aggravated assault."
The wife was taken in for questioning and faces that elevated aggravated assault charge.
The couple is not yet being identified, but police are familiar with them
Sheriff Mason added, "My agency the sheriff's office, and the state police have been to this residence in the past for various calls for service."
Police say the woman is cooperating.
Sturtevant Hill Road was limited to one lane into the evening during the investigation.