You've got a drywall patch to make.

Everything you are seeing is cosmetic and to be expected with age in unconditioned space. And you are right,it's paper tape peeling.

@klem1 @Joseph Corlett, LLC Thanks! However, what if it's a new crack, or continues to develop - which it looks like it might based on the faint outline? Does that mean there's a load or structural issue?

What is the beam's size?

What is the beam's composition?

What is the beam's span?

What is the beam supporting?

(it appears the problem is cosmetic. I am just asking the questions to make you feel better)

No load issues.

Thanks everyone! The beam is probably about 8" wide and maybe 12" tall (this includes the sheetrock of course). It's a townhome so it spans the other units wall-to-wall. It's supporting a second bedroom upstairs (12'x14'), which I converted to a home gym 2 years ago. Luckily I'm small so I don't have a ton of weights up there. I have a squat rack (200 lbs), barbell (45lbs), dumbbells (100 lbs total), and plates (180 lbs). I also put down 2 layers of plywood + rubber flooring up there to distribute the weight of the equipment for a 6'x8' raised platform. I never deadlift or slam weights. It may sound heavy but I think if you add it up it's not really much heavier than heavy duty furniture. I recall checking the building codes for load per sq ft according to the size of my room and I was still below that. I have not observed any buckling of the floor or separation of the floor from the wall. I took ownership of this home 3 years ago and if I look at my inspector's old photos of the garage there is one area where I can see that the crack was already there. The others I can't tell since his photos were too low-resolution or far away.

World's Strongest Man 4x Brian Shaw in his home garage gym.

There's a reason home gyms are usually set up in garages or basements.

Even under expected loading, our structural engineer has advised that the steel beams under a room over a garage will sag 1/4-1/2 in. 30 years.

(In past decades, I could lift 600 lbs off a power rack. I would hate to drop that on the floor!)

Apparently the drywall contracor used paper tape instead of a metal corner bead at the beam. Paper tape separation is not a "crack".

Of course it is a crack in the plaster coating!

Was the space above the garage designed as habitable space? If yes, then I wouldn't worry too much, but might be worth having it looked at if it gets worse.

" but might be worth having it looked at if it gets worse. "

Could be but until it does get worse op should be worried about high taxes instead.

Yeah the bedroom upstairs was designed to be a habitable space absolutely.

Thank you again all. Boy, I was certain most of you would berate me for having a small home gym in half the room upstairs and would've changed your tune to say it was structural. Thank goodness...I do feel better.

And I'm very worried about high taxes, lol.

Posters stand fully behind their assessments. (But not under them.)

If you mean to imply there's blowhards scattered amongst experienced advice givers, I 100% agree worthy.

I see a metal cornerbead on the outside of the beam. Realize that structural members are designed to "sag," meaning there will be a change in "levelness" and that is accounted for and ok. To give you an idea, take the span (in inches) and divide by 240 to see an allowed "sag" of a beam (20' for a garage = (20'x12)/240=1, so that beam could "sag" up to 1" under loading). The capacity of the beam is in thousands of pounds, so I don't think some free weights will overload it (notwithstanding worthy's herculean strength).

Also a garage's drywall will crack and separate because it is exposed to cold vs warm quite often and things move with temperature changes.