How do Army service stripes work (I've seen some service stripes only worn on the left sleeve but sometimes on both sleeves)?

SFC Melker Johansson - As a Retired (Armored) Cavalryman, can readily respond. Yes. Service Stripes worn on both sleeves are both larger & flashier, but amount same thing. (Three years Active Service) However, believe Overseas 'Bars' on right, too.

LTC Jason Mackay - The bars on the right sleeve are for time in combat zone. Time done else where overseas does not count for the stripes on right sleeve.

Army hash marks, of left for left sleeve each for three years, on right Overseas hash mark for six months in combat zones. Only enlisted member year the three year hash mark, Commissioned Officers and Warrant Officers however as well as enlisted member wear the overseas bars for each six months.

That ais interesting. See you can learn something new every day.
In the Corps you get a 'stripe' for four years duty, worn on both right and left sleeve.

Overseas service bars

If one is coming from another branch do you still get overseas service bars from prior deployments from the other branch?

Right sleeve is combat zone NOT overseas or deployment outside the combat zone.

Thank you Maj. I served 18 months in Germany in late 60s. That does not qualify for a bar on right sleeve. I served 13 months in Viet Nam, that qualifies me for 2 bars on right sleeve.

Ah, I met a guy who was wearing army dress blues at a wedding with service stripes on both sleeves, I'm guessing it was stolen valor then?

Not necessarily, the dress blues and service uniform are two different types of uniform. The service uniform replaced the old green uniform. Now, the dress uniform is more for especial occasions and it's a little more expensive. Now, as far stolen valor, if this individual had some funky stuff on his uniform that doesn't look right, that's a different story. Look up the Army Service Uniform and the Dress Blues, they both look a little different. I hope this cleared out better.

Will Boyd - NO, those large stripes on both arms were on the older Army dress blues.