You need 120 qualified payment periods, which equate to 10 years of making monthly payments on your loan (a payment period is effectively 1 calendar month). PSLF doesn't grant loan forgiveness until you hit 120 qualified payments, and it only grants full forgiveness, not partial.

Under President Biden, PSLF is currently allowing any and all repayment plans to apply, but previously, you had to be in an IDR repayment plan in addition to meeting the other requirements.

From March 2020-August 2022, you don't have to make monthly payments on your student loan, but each payment period is still counted toward your 120 goal, as long as you were working full time for a non profit employer (equates to about +29 payments).

If you have multiple loans with different ages, you should consolidate them into 1 loan, and then all of your loans will get the highest payment count that you have established via submitting ECFs for all the nonprofit employers you were working for during the payment periods that you want them to consider.