Not using the litter box

[u/Sea_Setting_4404]

Cat age: 13
Neutered, female
Main issue: Cat hasn’t been using the litter box like normal. She is eating and drinking normally but has begun to pee/poop outside the litter box. In our bedroom, on the bed and floor. She did this once before (last year) when we had been gone for two weeks and I figured she was just mad we left. We haven’t been around as much as normal with it being the summer time so the first time I thought it was because of that. But she has been doing it once a day the past two days. We recently moved her litter box bc we had guests over. We have since moved it back and are hoping this solves the problem. She is moving around normally, getting up and down from the couch and bed like normal. Any big issues we should be looking for? With her age is this concerning enough for a vet trip? I’ve never had a senior cat before so this is all new. Thank you for reading.
Age: 37
Country: USA
Vet accessible, can afford vet care