I had eight loans with Sallie Mae (they have since been sold to someone else). The eight loans appear correctly on my TransUnion and Equifax reports, but they do not show at all on my Experian report.

I really wouldn't care, but according to myFICO, one of the negative factors of my Experian score is "The length of time your accounts have been established is relatively short." Adding these loans to my report would increase the length of my Experian credit history from 10 years, 11 months to 13 years, 8 months (like the other two reports).

How do I go about trying to get the Sallie Mae loans on my Experian report? Ask Sallie Mae or Experian?

TIA

Ask SLMA. Experian cannot make SLMA report to them.

I have a bunch of loans through SallieMae too. They definitely report to Experian as of this month. They're on my other two reports but I gotta check and see if they still report currently or pick and choose. But definitely Experian right now.

all 3 for me

All 3 for me, and has for years.