Starting Jan. 1, nearly five million people who were supposed to be covered under Obamacare won’t be because their states have refused to expand Medicaid.

The Medicaid expansion field is tentatively set for 2014, and the nation is split down the middle: 25 states (plus D.C.) are expanding, and 25 states are not, according to the Kaiser Family Foundation.

Ohio became the 25th state to join the expansion last month, and more states could still sign onto it. Pennsylvania Gov. Tom Corbett (R) has proposed an alternate form of expansion that would require federal approval, and Terry McAuliffe’s election this week as Virginia’s next governor increases the likelihood that his state will eventually expand the program. New Hampshire Gov. Maggie Hassan (D) has called a special legislative session this month to try to hammer out an expansion deal in her state.

But for now, according to the foundation, 4.8 million Americans won’t be covered as the law intended in those non-expanding states. They don’t qualify for Medicaid now, but would have under the expansion, and they don’t make enough money to qualify for financial help to buy private coverage. They’re Obamacare’s other losers, while media coverage focuses on those people whose individual policies are being canceled under the law.

A quick reminder of how this happened: Obamacare was written with the intention that every state would expand Medicaid, the low-income public insurance program, to 133 percent of the federal poverty level. The expansion would have accounted for about half of the people who would get covered under the law (17 million, according to the Congressional Budget Office). Many of the newly eligible people would have been childless adults who currently aren’t eligible for the program in most states.

It was supposed to be a good deal for states, too: the federal government would cover 100 percent of the costs for the first three years and never less than 90 percent after that.

But then in June 2012, the U.S. Supreme Court ruled that, while Obamacare would stand, states would have a choice about whether or not they would expand Medicaid. Since then, half the states, all of them with either a Republican governor or a GOP-controlled chamber in the legislature (or both) that opposed the change, have declined to participate.

The other thing to consider is that it’s the poorest people who make up those 4.8 million who are missing out. Because of a kink in the law’s language, people between 100 and 133 percent of the poverty level will still be eligible to receive financial help to purchase private coverage on the insurance marketplaces that opened Oct. 1.

But those actually in poverty will be out of luck.