People who purchased insurance through the Affordable Care Act's marketplace had one-third fewer choices in health care providers than those covered by employer plans, according to a new analysis.

A report released Wednesday by consulting research firm Avalere Health found that plans offered through the ACA's exchange offered an average of 34% fewer providers in network compared to the choices provided by the average employer-based or individual non-exchange commercial plan.

Avalere examined plan network regions of the five states with the largest exchange enrollment — California, Florida, Georgia, North Carolina and Texas — and compared the average number of providers included within exchange network with those in nonexchange commercial networks for the same region.

The study found plan networks offered 32% fewer primary-care and behavioral health providers, 42% fewer oncology and cardiology physicians, and nearly a quarter fewer choices of hospitals.

“Plans continue to test new benefit designs in the exchange market,” said Dan Mendelson, CEO at Avalere, in a statement. “Given the new requirements put in place by the ACA, network design is one way plans can drive value-based care and keep premiums low.”

The analysis raises further questions regarding the efficacy of exchange plans to provide greater access to healthcare services to the more than 11 million individuals who have enrolled.

Insurers have traditionally opted to offer exchange plans with smaller provider networks as a way of offering lower premiums to consumers. Limiting the number of providers in a network allows payers to select a few providers who are willing to accept a lower reimbursement rate in exchange for a greater number of patients.

Results of a survey released in May by the Kaiser Family Foundation seem to indicate affordability was a greater factor in exchange enrollees' decision-making than the number of provider options a plan offered. Cost was considered “somewhat” or “very” important among 82% of those surveyed, compared with 60% who reported the choice of doctor or hospital being more important.

Steven Ross Johnson writes for Modern Healthcare, a sister publication of Business Insurance.