Just to complete the math, if you add $3,000 to your MA this month and raise it to the BHS ($66,000), and if you never withdraw from it (someone else pays your MediShield Life, CareShield Life, and Integrated Shield premiums) then you'll earn 4% interest on $63,000 for one month and 4% on $66,000 for 11 months. That equals $2,520. So if your SA has reached the FRS then you get the lion's share of your $3,000 bouncing into your OA on December 31, 2022. And you can get tax relief on the $3,000. And that's not even counting the compulsory contributions -- the MA portion of those bounces into your OA too. So if you want more OA inflow (for housing as a notable example) then having MA=BHS and SA>=FRS works really great.