Allowing healthcare providers to opt out of testing bundled payment models could deal a “severe blow” to payment reform efforts and the future of the bundled payment program, according to some experts.

In a blog post published Monday in Health Affairs, researchers with the Brookings Institution examined how the Trump administration may proceed with bundled payments, especially given Department of Health and Human Services Secretary Tom Price’s, M.D., previous criticisms of the models.

“We argue there is some scope to modify these models to address concerns raised by Secretary Price and others without damaging the integrity of the models,” the authors wrote. “However, making these models optional would eliminate the ability to generate robust evidence on their effectiveness, dealing a severe blow to efforts to use bundled payments to improve care delivery … and to the chances for bringing bundled payments to scale nationally in the coming years.”

Republican lawmakers, including Price, also voiced concerns about the bundles’ mandatory nature in a letter sent to the Centers for Medicare & Medicaid Services last year. In that letter, Price and others bashed mandatory models as “experimenting” with patient lives without large-scale evidence to show that they’ll bring results.

But allowing selective participation can also be detrimental to testing outcomes, the post’s authors argued, by delaying rolling out the program on a national scale and damaging the work of CMS’ Innovation Center. Doing away with mandatory models also could cut the Innovation Center’s savings, they said.

“If bundled payments are ever to reach national scale in Medicare or elsewhere, we will need evidence that they work for all providers, not just ‘early adopters,’” the post reads. “Such a retrenchment could have ripple effects for private payment reform efforts that attempt to complement CMS programs.”