If it looks like someone is understating his income by more than 10%, and the exchange doesn’t have other sources to quickly check against, the exchange may choose to rely on what the applicant says.

But in those cases, the exchange must also conduct a random sample of similar applicants to make sure the verification process is working.

In the end, if someone slips through the cracks — and gets more of a subsidy than he is entitled to — he still could be found out.

That’s because the exchanges are only approving estimated tax credits that a person can use to help pay their insurance, said Larry Levitt, a senior vice president of the Kaiser Family Foundation.

The final calculation of a subsidy’s size will be done after the fact by the IRS.