Pretty much, yes.
But keep in mind there may be PPI requirements. If said printer requires a file at 100% at exactly 300PPI and your image isn't exactly 300PPI at your required size then you will have to resample your image. Most printers will have a minimum not exact PPI requirement, but it is a possibility and I have seen requirements within a range (say 250–350 PPI).
If you open your image in Photoshop (or similar, but I'll use Photoshop as an example) and open the Image Size dialog, uncheck 'Resample Image' and change the physical dimensions to the size you need (i.e. your printers 100%), the PPI will change automatically and leave the pixel dimensions of your image intact. If the PPI value is within any requirements you are good to go—without changing a single pixel.