Q: Context: In the United States Army, United States Marine Corps, and United States Air Force, general (abbreviated as GEN in the Army or Gen in the Air Force and Marine Corps) is a four-star general officer rank, with the pay grade of O-10. General ranks above lieutenant general and below General of the Army or General of the Air Force; the Marine Corps does not have an established grade above general. General is equivalent to the rank of admiral in the other uniformed services. Since the grades of General of the Army and General of the Air Force are reserved for wartime use only, and since the Marine Corps has no five-star equivalent, the grade of general is currently considered to be the highest appointment an officer can achieve in these three services.

Question: what is the highest number of stars a general can have?
Let's give stream of consciousness below
To answer the question, consider the following: In the United States Army, United States Marine Corps, and United States Air Force, general (abbreviated as GEN in the Army or Gen in the Air Force and Marine Corps) is a four-star general officer rank, with the pay grade of O-10. So the answer is four.