The main revenue source for the House health care bill is not indexed for inflation, meaning that more and more people each year will face a tax that is being sold as a levy on millionaires.

It’s a significant change in approach that will help align revenues and costs in the latest version of the bill, but it will invite criticism and comparisons to the alternative minimum tax, which has affected far more people than it was supposed to.

Starting in 2011, the House bill would impose a 5.4 percent surtax on adjusted gross income above $500,000 for individuals and $1 million for married couples. Because some Democrats expressed concern about the potential effect on small businesses that pay through the individual side of the tax code, the party’s leadership scrapped an earlier plan that would have imposed a smaller surtax on individuals making more than $280,000 and married couples earning above $350,000.

However, the earlier version included annual inflation adjustments designed to make sure that the tax’s reach did not creep down the wealth ladder as nominal incomes rose each year. The lack of such adjustments in the alternative minimum tax (AMT), which was originally designed to affect only the wealthiest Americans, forces Congress to routinely pass “patches” to prevent the tax from hitting tens of millions with more moderate incomes.

The Senate Finance Committee’s health care bill also includes a core revenue provision that will gradually ensnare more people because of how it is adjusted annually. The committee’s proposed excise tax on high-cost health insurance plans includes thresholds that are indexed for inflation, but at a slower rate than health care costs have been growing in recent years. That approach is part of a strategy to force behavioral changes in the way that companies compensate employees, by equalizing the tax treatment of wages and health care.