> What's the situation where it's better to enroll in HSA? I always do FSA, but I'm scared to enroll in high deductible plan (requirement to enroll in HSA) because for a typical primary care visit, for FSA, I only pay $20 Copay,

FSA is not the insurance plan. Neither is HSA. Read the details of the actual insurance plans! Compare the premiums, coverages, and other employer-provided benefits.

> but with high deductible plan, I need to pay 20% coinsurance. Thanks in advance for the info.

No, you don't just pay coinsurance. You pay the insurance-negotiated full amount until you reach deductible. Then you pay coinsurance until you reach out-of-pocket max.

There is a sweet spot where a non-HDHP PPO is better than HDHP, where you use medical services just frequently enough but not too much.