Can someone with DACA (Deferred Action for Childhood Arrivals) qualify for an exemption from the tax penalty? They have a work permit with a valid social security number but I think they still consider undocumented because this is only a temporary protected status.
The short answer is that Deferred Action for Childhood Arrivals (DACA) don't owe the fee and can't get cost assistance under ObamaCare. You can use the Marketplace or get employer coverage, but don't have to pay the fee for not having coverage.
You won't find this information in the law, it was clarified by the IRS after the law was written.
You can learn more about DACA and ObamaCare here.