More Americans will owe the government money for their Obamacare subsidy than won't, says a new analysis.

A big upcoming Tax Day question is how many Americans with government-subsidized health insurance will find that they collected more in subsidies than they're qualified for and have to pay some of it back — and how many will find themselves in the opposite position, with the government owing them money.

The Kaiser Family Foundation estimates that half of all subsidy-eligible households will be in the first boat, owing the government an average payment of $794. That situation comes about if a taxpayer earns more than they originally guessed, thus qualifying for a lower subsidy level.

Meanwhile, 45 percent will be in the opposite situation, finding that they qualified for more in subsidies than they collected. Their average refund will be $773, Kaiser estimates.

The subsidies are provided through President Obama's healthcare law to help low and mid-income Americans buy health insurance.

Taxpayers can minimize the discrepancy by promptly reporting any income changes to the online marketplace where they bought their health plan. Still, many subsidy recipients are likely to find their income fluctuated throughout the year, especially if they work in an hourly job.

"An unanticipated repayment — which may require tax households to actually write a check to the IRS or get a lower-than-expected tax refund — may be difficult for these households to handle financially, even though it would only happen if their income is higher," the Kaiser analysis says.

Congress has twice capped the amount subsidy recipients would have to pay back. Those with lower incomes will have to pay back less, while those earning more will have to pay back larger portions of any overpayments.

But there is one group of people who must pay back the full amount: those who ended up earning more than 400 percent of the federal poverty level, which disqualifies them from collecting any subsidies at all.

These earners could face much higher payments than those with lower incomes, Kaiser estimates. If a family estimated their income would be between 300 and 400 percent of the federal poverty level — but then they ended up earning more than 400 percent — their average repayment would be $2,306.

Four hundred percent of the federal poverty level equals $47,080 for an individual and $97,000 for a family of four.