Two Republican Senate leaders asked the Institute of Medicine this week to include estimated cost increases in insurance premiums (PDF) within the calculations it is required to produce for coming standardized insurance packages.

The request by Sens. Mike Enzi (R-Wyo.), ranking member on the Health, Education, Labor and Pensions Committee, and Orrin Hatch (R-Utah), ranking member on the Finance Committee, stems from the long-held Republican contention that coverage mandates in the 2010 law will accelerate rising health insurance costs. Specifically, the law requires regulators to develop a series of increasingly generous standardized insurance benefits, known as essential benefits packages, which people can buy through coming insurance marketplaces.

“If the secretary defines an essential health benefits package that includes a high number of mandated benefits and mandated providers, premiums will increase, taxpayer costs will rise, and patients will have fewer choices in deciding the plan that best meets their needs,” according to the senators.

The healthcare law requires the IOM to provide an analysis of what coverage the benefits packages should include.

The senators asked the IOM to include in its report an emphasis on affordability and “consumer choice.”

“We urge you to fully consider the impact of federal benefit mandates on taxpayers and patients and avoid a one-size-fits-all approach in the recommendations you provide.”