Hundreds of thousands (perhaps even millions) of newly insured Americans will be covered starting Jan. 1, 2014, by the health insurance exchange products being peddled as part of the Patient Protection and Affordable Care Act. Some experts believe this influx of new patients will lead to physician shortages in both primary-care and specialty realms — and those shortages could become even more pronounced due to some physicians choosing not to contract with the payers offering coverage through the health insurance exchange.

Physicians in some states won't have a choice if they've already signed contracts that contain all-products clauses (the legality of which varies state by state). However, those physicians who do have the option to accept or walk away from contracts with health insurance exchange payers all cite one big reason why they won't be participating in those contracts: money. Or, to be more precise, a lack thereof.

"The reimbursement is lousy," says Diane Haugen, general manager of Harvey Clinic, in Harvey, N.D. "We're a small, independent practice, and our clinic's in a rural community with many farmers. Many of them are having their insurance canceled because they all had individual policies — not a group policy where they got some protection. And they aren't able to sign up for anything else yet."