To repeat, DII is not Unemployment Insurance (UI). Critical Illness insurance is not UI either. If you're fit for work and unemployed, for whatever reason(s) you're unemployed, then DII doesn't provide payouts.
In the scenario you describe, DII would pay at least 6 to 10 months of benefits (how long depends on the policy's waiting period, which can range from 2 to 6 months depending on carrier and policy). If he's fully fit for work after those 12 months, then payouts would stop.
Can we agree that being both fit for work
and unemployed in Singapore for two years is a voluntary choice? Yes, it's entirely possible to be retrenched and not able to find a job with a similar salary, but that's already true, every day. Neither DII nor CI are designed to cover retrenchment risks. UI is, but unfortunately UI is barely available in Singapore since the moral hazard problems with it are difficult for a private market to address, and the government doesn't seem interested in UI.
I'm not an insurance salesperson, and I'm not selling anything else for that matter.
To obtain quotations for DII, contact the three insurance carriers
discussed here, and also ask for a quotation on Aviva's MINDEF/SAF Group Disability Income Insurance if you qualify for that. You will need to provide the agent with information about your profession -- if the agent is not sure which profession you fit into on the agent's list, and if two or more choices on the agent's list genuinely match your profession, ask the agent to run the premium both/multiple ways -- and how long you'd like the policy to run (to age 65 I'd recommend), how long a waiting period you want (6 months I'd recommend if offered, or longest available if no choice), and what amount of monthly income you want to insure (up to 75% of current income, except for the Group MINDEF/SAF plan which is up to 50%). I recommend you pick a
reasonable number that you could live on and not necessarily insure up to the maximum ($11.2K) if you're pulling down $15K/month. One of the three insurers also offers an escalating payout option -- that is, once payouts start they escalate each year -- and I think I would choose that. Ask for a copy of the full policy letter, and read it carefully. Pay close attention to how well the policy tolerates working stints outside Singapore and bouts of unemployment (how long you can be unemployed before coverage lapses) -- these details can matter. You are free to "stack" policies if you wish, i.e. buy some amount of coverage from Carrier A and some amount from Carrier B, as long as the total coverage is still within the 75% "moral hazard" limit. And sometimes it makes sense to do that, actually. Maybe one carrier has a great premium promotion, but you like another carrier's T&Cs better, so you mix some coverage across those two carriers.
Good luck.