Rep. Graves: Essential-benefits policy too hard on small businesses

The healthcare law spells out 10 categories of essential benefits — services that insurance plans will have to cover, beginning in 2014. HHS plans to let each state fill in the details within those 10 categories, for fear that a prescriptive federal definition could raise costs across the board.

Nevertheless, any new coverage means at least some new costs, Graves said.

"There are many small business owners who will struggle to afford any coverage, let alone the comprehensive or 'supplemental' coverage envisioned by the proposed rule," he wrote. "Others will simply not be able to provide coverage and be forced to pay the penalty. Requiring policies to cover extensive benefits will only make health insurance more, not less, expensive."