ClintB: You are either entitled to a retroactive forbearance or are not, the exception being a general forbearance (which is left up to the discretion of the servicer.) The list of types of forbearances is available on the student loans website. Once you choose which one you would like to apply, you will also need the supporting documentation.
Each servicer is different in how far back they will allow it to be applied. I would call them and simply ask how far back they apply a retroactive forbearance. No other questions for this call. They tend to be most responsive to asking general questions rather than providing actual help, so I would save that for a different call. It's often best to speak with an account specialist too. You could even contact them with a fax or letter; this will provide you with a written copy of their policy you may need later.
I would not wait. Showing good payments is likely irrelevant; waiting may end up meaning you are ineligible for the retroactive forbearance due to the deadline your servicer set. Sometimes the first answer you get is not the final/ right answer, so be persistent.
When you are finished and it is granted, you may have to update the CRA yourself as servicers often refuse. Just submit a copy of the granted retroactive forbearance with a dispute and the lates should be removed.
Federal Student Loans fall under the HEA (Higher Education Act) which supercedes the rights granted to you by the FCRA. While a credit card company may be able to grant you a goodwill, servicers are required to report your account accurately. They cannot forgive late payments. You're still welcome to ask, they are just not allowed to grant it to you by law.
https://studentaid.ed.gov/sa/repay-loans/deferment-forbearanceIf you have any more questions feel free to ask. Good luck
