What is the proper way to address NCOs in different branches?

I was always taught that the informal term was ‘Top’ for USMC Master Sgt. and Master Gunnery Sgt. May God have mercy on your soul if you used that term with a First Sgt. or Sgt. Major.

As many people have already shared, the proper way to address the Marine senior NCO would be "Gunnery Sergeant." However, I think it is vitally important that enlisted service members always remember that an E-7 designation is a pay grade and not a rank. Too many times we hear of someone addressing a service member as an E-5 instead of as a Sergeant (USA & USMC), a Petty Officer 3rd Class (USN & USCG), or a Staff Sergeant (USAF). Since most would never consider addressing a Captain (or Navy Lieutenant) as an O-3, then my recommendation is that the same is true for enlisted service members.

In the Air Force E-1 through E-4 it acceptable to say airman. SrA that have gone through NCO course to the young troops it’s sir/ma’am or SrA. E-5 and up its Sgt, sir or ma’am. For E-8 and E-9 senior or chief respectively in an informal setting and in a formal setting it’s always sir or ma’am or the full rank. First sergeant is different as in the Air Force they can be E-7 and up and both formal or informal it’s first sergeant or their rank. Informal you can get away with call them shirt or first shirt.

When I was in you only addressed an officer as Sir.

when in boot camp, call ALL persons ABOVE recruit as SIR or MA'AM !!!!! Afterwards, call them by their appropriate ranks...where it be Petty Officer, Sergeant, Ensign, whatever rank the person carries...it is common sense AND courtesty all rolled up in one package...Just saying...God bless everyone !!

Learn their rank titles and be polite in case you're wrong.
Navy= Petty Officer (E-4 thru E6) and Chief, Senior Cheif, or Master Cheif.
Army= Specialist, Corporal, or whatever grade of Sargeant they are.
Marines= Corporal or whatever grade of Sargeant they are.
Air Force= Airman 1st Class or whatever grade of Sargeant they are.

In the Marines we dont start off as privates, they start off as recruits, thats why you heard them addressing everyone as sir/ma'am. Otherwise if you know the rank you use that, if you dont sir/ma'am is acceptable, and most people wont give you a hard time. Ie in marpat woodlands its notoriously hard to see the amount if rockers or the device, so sir/ma'am is better then not saying anything

Caveat to above: Army, USMC & USAF all use a Diamond to denote 1st SGTs and Stars to denote SGTs Major; Eagle and two flanking stars = SR NCO of Branch of Service (SMA, SMMC, CMSAF).

NOTE: USAF allows 1st SGTs in E7/8/9 pay rates

Army (E5-8 not 1st SGT/1SG) = Sergeant
Army (E8 1st SGT/1SG) = 1st Sergeant
Army (E9 SGTs MAJ/SGM/CSM all) = Sergeant Major
Navy (E7 CPO all) = Chief
Coast Guard = Same as above
USMC = Similar to Army though E7-8 =Gunney or Master Gunney if not 1st Sergeant
Air Force = Sup Guy, May also use first name if known or wink and say “hey there”...
Space Force will most likely follow Star Trek format, so watch that for further guidance...

-OUT.

Air Force Guidance
E-9: Chief (when you're a chief, chief is your name)
E-8: Senior+name
E5-7: Sergeant+name
First Sergeant: Shirt, First Shirt
E1-4: Airman+name
You can call anybody sir in the Air Force, regardless of rank

Colonel, your response about calling Air Force personnel by their first name is an insult to every NCO and officer who ever donned a uniform. I don’t take your insult lightly, and, quite frankly, don’t give a dam what you did on active duty. I have no respect for any superior officer who, in any way, who disparages any enlisted person or junior officer. You are a disgrace to the uniform you wore.

I just say "what up dude/bro" seems to work

That’s because it’s boot camp everyone is address as sir or ma’am by recruits . Once out of boot camp the only officers are address as sir or ma’am

I've been told by a lot of higher ups, you should try and know the other branches rank system but if you don't sir or ma'am is the best way to address. Then that person may or may not clarify what rank they hold.

Being raised USAF everyone from E4 to E9 was Sgt. After being in the USN everyone from E4 to E6 was either Petty Officer or first/last name. E7 was Chief, E8 was Senior, E9 was Master Chief. CWO's and Mustangs was a whole different ball game, Sir was a safe bet.

No you don't call them sir. Only recruits call them sir because "there not Marines yet". An E-7 is addressed as Gunnery Sergeant or just Gunny if you know him and he is ok with you calling him/her that.
Staff Sergeant E-6 is called staff sergeant and not just sergeant. I'm army I learned that the hard way when I was an E-4.

Also it's good to know that as a Specialist you are not required to address there corporal's by there rank there the same rank as you. Also regulation state you will address someone who out ranks you by grade not rank. So don't ever let one of there corporal's push you around.

To this day after being out for awhile I still address the military by their rank. They have earned my respect

As to the response for the Air Force member addressing an NCO of another branch by their first name...I would have hemmed an Airman up if they addressed anyone other than sir or ma'am.

Sir yes sir...

This will be fun. I had the pleasure to work alongside the sister services while deployed to OIR (Op. Inherent Resolve) last year and you quickly pick up on the culture of the other branches. We called USMC Master Sergeants Top, Gunnery Sergeant's Gunny (Master Gunnery, Master Guns). All medical personnel were doc regardless of branch. Senior was just that. In the AF, the senior most NCO was simply senior. Varies by person to person and situation to situation but when using their rank, you can never go wrong.