Can You Buy T-Bills With CPF OA Savings, And Is It Worth It?

Faizal Hamid, 36, is a civil engineer who earns $6,500 a month and takes home $5,200 after CPF. He has $45,000 in his CPF Ordinary Account, and his family's flat loan is serviced from his wife's account. In September 2026 a colleague tells him that Treasury bills (T-bills) have paid more than the 2.5% his Ordinary Account earns, and Faizal asks whether moving his CPF savings would add anything.

CPF members can use Ordinary Account savings to buy Singapore Government T-bills through the CPF Investment Scheme (CPFIS), on the same terms as cash and with a $1,000 minimum. The money then stops earning the 2.5% a year the Ordinary Account pays, which the CPF Board has kept at that legislated floor through September 2026. Because of how CPF counts interest, a 6-month T-bill usually costs seven or eight months of that interest.

At eight months lost, a 6-month T-bill needs a cut-off yield of about 3.3% to match leaving Faizal's money in the Ordinary Account. The sections below follow his application, how the lost months arise and what the latest auctions paid.

Can He Buy T-Bills With His CPF?

According to the CPF Board (checked 30 September 2026), a member can invest Ordinary Account savings in T-bills if they:

• are at least 18 years old
• are not an undischarged bankrupt
• have more than $20,000 in the Ordinary Account
• have completed the CPFIS Self-Awareness Questionnaire

Only the balance above $20,000 can be invested. With $45,000 in the Ordinary Account, Faizal can put up to $25,000 into T-bills. A younger colleague with $18,000 in the Ordinary Account cannot invest any of it.

How Does He Apply?

1. Complete the CPFIS Self-Awareness Questionnaire on the CPF website.
2. Open a CPF Investment Account with DBS, OCBC or UOB, the three CPFIS agent banks.
3. Apply for the T-bill through the agent bank's internet banking or app before its closing date.
4. Check the allotment once MAS publishes the auction results.

The CPF Board deducts the Ordinary Account only on successful allotment. The Monetary Authority of Singapore (MAS) states that CPFIS applications are deducted within one to three business days after the auction date. For a late-September auction, Faizal's $25,000 would leave his Ordinary Account in September.

Read Also: How To Buy T-Bills In Singapore: Bids, Cut-Off Yield And Payment In 2026

How Many Months Of CPF Interest Would He Lose?

The CPF Board (checked 30 September 2026) computes interest monthly under two rules:

• Money deducted in a month earns no interest from that month onwards.
• Money received in a month, including refunds, starts earning interest the following month.

A T-bill auctioned in late September, with the Ordinary Account deducted in September, earns no CPF interest for September. A 182-day bill issued on 29 September 2026 matures on 30 March 2027. The CPF Board credits maturity proceeds to the CPF Investment Account within one week, so they arrive in early April. If Faizal returns them to the Ordinary Account in April, CPF interest restarts in May.

That is eight months without Ordinary Account interest, from September to April, for a bill that ran six months. On his $25,000, the interest given up is $25,000 × 2.5% × 8/12 = $416.67.

What Cut-Off Yield Would Beat His Ordinary Account?

On $10,000, the Ordinary Account pays $10,000 × 2.5% × 8/12 = $166.67 over eight months. A 182-day T-bill at a cut-off yield of R pays $10,000 × 182/365 × R, so it matches the Ordinary Account at R = $166.67 ÷ $4,986.30 = 3.34%.

Source: CPF Board interest rules, MAS discount formula; bank charges are excluded

The break-even yield does not change with the amount, so Faizal's $25,000 needs the same 3.34% in the eight-month case. Seven months is the best case, when the deduction and the maturity fall in months that let the member return the proceeds straight away. The 1-year bill loses the same one or two extra months over a longer term, so its break-even yield is closer to 2.5%.

The table below lists the latest T-bill auctions in the MAS issuance calendar. A cut-off yield below the figure in the right-hand column of the table above leaves the member worse off than leaving the money in the Ordinary Account.

Source: MAS, issuance calendar as published on 22 September 2026

What Happens When His T-Bill Matures?

According to the CPF Board (checked 30 September 2026), maturity proceeds go to the CPF Investment Account, not the Ordinary Account. The member can buy another T-bill with them or return them to the Ordinary Account through the agent bank.

If the member does nothing, the CPF Board returns the money to the Ordinary Account once the CPF Investment Account has been inactive for two consecutive months. The CPF Board notes that a member can lose up to two months of CPF interest this way, which is the "up to 10" row in the table. For Faizal, ten months would mean $25,000 × 2.5% × 10/12 = $520.83 of interest given up.

Read Also: CPFIS: Limits, Fees And The 2.5% Return To Beat

Is Buying T-Bills With CPF Worth It For Him?

Faizal completes the questionnaire and opens a CPF Investment Account, then sets a rule for himself. He bids $25,000 for a 6-month bill only when the latest cut-off yields sit clearly above 3.34%, and he returns the proceeds or rolls them into the next auction in the month they arrive. When they do not, his $25,000 stays in the Ordinary Account at 2.5%.

Rolling from one 6-month bill to the next avoids the return trip to the Ordinary Account, so the extra months are lost once across the whole run, at the start and the end. Members for whom the latest cut-off yields sit near or below 2.5% gain nothing by moving the money. The answer depends on the auction yield at the time, the member's timing and how much attention they can give the CPF Investment Account.