Originally Posted by Salary.sg

Suppose you have:
OA 151k
SA 151k

Without shielding, after you turn 55, you will have:
OA 121k <-- 2.5%
SA 0k
RA 181k

With shielding (after T-Bills mature):
OA 10k
SA 111k <-- 4%
RA 40k+141k

The difference is that you will have 111k earning 1.5% more.