————–For a first lieutenant and spouse, see Couple, Military
How to Address a First Lieutenant
First Lieutenant: USA, USMC or USAF
—-Envelope or address block on letter or email:
——–First Lieutenant (Full Name), USA/USAF/USMC
——–1LT (Full Name), USA
——–1st Lt (Full Name), USAF
——–1stLt (Full Name), USMC
—-—-Which looks like:
————-First Lieutenant James Smith, USA
—-—-Dear Lieutenant (surname):
—-#1) In the past, forms of address for Army lieutenants varied slightly from Air Force and Marine Corps lieutenants, but current directives show the forms of address to be identical for all services.
—-#2) Above I’ve shown the rank fully spelled out & with the service-specific abbreviations for the ranks. Both spelling out and using service-specific abbreviations are correct. If you are looking for more detailed information, including the service-specific abbreviations, look in my book: I get into it all there.
— Robert Hickey How to Address a First Lieutenant