Every year, you can top up cpfRA_bookVal to the ERS watermark. All cpfRA accrued interest goes to your cpfRA not the pool, but excluded from cpfRA_bookVal.

After startOfPayout (age 65 to 70), under the Standard plan, your interest accrual would be redirected into the pool. (cpfRA emptied.)

— compare to cpfSA .. in Feb 2025, CPF hotline told me this bookVal rule is different from cpfSA top-up, where the engire cpfSA balance is compared to the FRS watermark. I think this is the rationale:

PAP government encourage citizens to top up cpfRA and cpfSA but there has to be a per-capita quota for top-up, not unlimited top-up. Government provides more encouragement to cpfRA than cpfSA top-up.