Actually, it doesn't take too much.

Bryan Caplan explains:

Awhile back, Krugman loudly insisted that if you ban pre-existing conditions clauses, you also have to mandate insurance. While the new bill has a mandate, it doesn't begin until 2014, and the penalty clause is absurdly small. Here's what passes for "promoting individual responsibility":

Requires most individuals to obtain acceptable health insurance coverage or pay a penalty of $95 for 2014, $325 for 2015, $695 for 2016 (or, up to 2.5 percent of income in 2016), up to a cap of the national average bronze plan premium. Families will pay half the amount for children, up to a cap of up to a cap of $2,250 per family. After 2016, dollar amounts are indexed. If affordable coverage is not available to an individual, they will not be penalized.

In practical terms, then, "Heads I win, tails I break even" remains the winning strategy. And as adverse selection drives up the drive of insurance, paying the uninsured penalty until you're seriously ill gets smarter and smarter.

Got that? Avoid getting health insurance and pay the fines. When you get sick, buy health insurance. It's that easy.