American citizens will be penalized for not buying health insurance but illegal aliens are specifically exempted from any penalties.  See Sec. 5000A(d)(3) of the health care bill.

Illegal immigrants often do pay income taxes through special individual taxpayer identification numbers (ITINs) issued by the IRS, so there’s no reason why they shouldn’t be subject to the individual mandate.

If illegal immigrants aren’t able to afford the purchase of health care or the health care penalty, there already is a special exemption for people whose income falls below a certain level, so low-income illegal aliens could have been exempted through that provision.  Under the law, illegal immigrants making plenty of money can get out of the mandate whereas an American citizen who makes far less money can’t get out of the mandate.

If there’s a concern about providing federal subsidies to illegal immigrants to help them purchase health insurance (there are subsidies in the bill to help people buy insurance), then just prohibit illegal immigrants from getting the subsidy.

I’m open to hearing compelling arguments as to why illegal immigrants are treated more favorably than those lawfully in this country under the health care bill.  I can’t think of anything yet.