You use the combination tag until it's filled up. Where legal you can put a native on the combination tag, only hatchery fish can be put on the harvest card.
If you wait til your regular tag is filled to purchase your hatchery tag, you will be too late....you are allowed to keep 20 native salmon/steelhead a year in oregon waters PERIOD. Once you have recorded #20 you are done for the year.
You are allowed to purchase "hatchery" tags to retain fin clipped salmon and steelhead. 10 hatchery fish per tag with no limit on the number you are allowed to purchase.
You do not have to buy a hatchery tag, you are allowed to put both native and hatchery fish on your combined angling tag. If you are just getting back into the sport. I would not purchase the hatchery tag unless/until you only have a few spots left on your regular tag.
You MUST have your LICENSE, COMBINED ANGLING TAG, and HATCHERY tag on your person while angling.If you plan on recording a fish on a Hatchery tag, you must have available spots on your COMBINED ANGLING TAG as well as on your HATCHERY TAG.