Easy answer: you're screwed.
But that's not the only way you can be screwed. Let's start with what "Critical Illness" coverage is and isn't.
CI pays the policyholder when that policyholder experiences some specific calamity that's on the insurer's short list.
Here's the "standard" list of 37 calamities, but policies can deviate from that LIA standard. (Check the fine print.) Enhanced Critical Illness (ECI) just expands the coverage in certain narrow ways, as the insurer defines it. CI/ECI is what I would call "cause-based" coverage, not really need-based (or outcome-based). It's "defined risks" coverage, not "all risks." Get a particular type of cancer, you're covered. Get run over by a bus, you're not, even if your financial needs are substantially the same in either event (can't work, need replacement income, maybe need some home/nursing care).
In Singapore, CI traditionally, notionally serves as income replacement insurance, and so that's why it stops at age 65 (a common retirement age). It's flawed income replacement insurance, but it very crudely serves that role in terms of market positioning.
If you don't like CI/ECI -- and I don't, for the record -- then you've got some other options (in combination):
1. Medical insurance covers, well, medical bills. In Singapore these are mainly Integrated Shield plans with optional riders (and barebones MediShield Life underneath). These cover acute care needs pretty well.
2. Disability income insurance (DII) provides genuine income replacement if you are disabled and unable to work (or only partially able to work). This coverage is "expensive" because it actually pays no matter what the cause(s) of your disability, with very, very few exceptions. ("Act of War" kind of exceptions.) Examples of DII in Singapore are Great Eastern's Pay Assure, Aviva's IdealIncome, and AIA's Premier Disability Cover. These policies are relatively recent innovations in Singapore (a problem for Singapore's long suffering financial consumers), but they're quite common around the world -- and the basic concept dates back to the 1700s in a few countries.
3. Long-Term Care Insurance (LTCI) pays out if you are unable to perform at least 3 (or at least 2, as an extra cost coverage option) of the 6 "Activities of Daily Living," as the policy defines them. In Singapore, ElderShield and ElderShield supplements are the most common LTCIs, available from three carriers. Once fully paid, ElderShield coverage is for life, but the base ElderShield policy will not pay for life even if the disability continues. ElderShield supplements are available to extend payouts to life, for as long as the "3 (or 2) out of 6" criterion is met. Another problem with ElderShield is that you cannot buy it until age 40.
4. "Total and Permanent Disability" (TPD) coverage, which pays a benefit if you experience a profound disability, as its name suggests. TPD is bundled with life insurance in Singapore.
5. "Personal Accident Insurance" pays out if you experience an accident, as the policy defines it. This is another cause-specific coverage, again not something I like.
6. Cash (savings) always works to solve financial needs, if you have enough cash.
DII tends to have the most reasonable (broadest) definition of disability, then LTCI, then the rest (which have lots of holes).
So, if you feel you need coverage before and after age 65, have a look at #1 (in public hospital form, I would strongly argue -- the private system is fundamentally broken right now), DII, ElderShield (and its supplements), and, of course, #6 on this list.
