OLYMPIA, Wash. -

Medicaid enrollments through Washington state's new health exchange have exceeded officials' expectations, but questions remain about whether there will be enough doctors to serve the influx of newly insured low-income patients.

The state Health Care Authority, which oversees the federal-state program for the poor and disabled, is in talks with the University of Washington and the Washington State Medical Association to do a statewide survey of doctors this summer to see if the federal health law's temporary bump in Medicaid payments to doctors was an incentive that helped keep or add providers in the Medicaid system.

That bump -- bringing the reimbursement rates up to the same level to Medicare, the federal program for those 65 and older -- was part of the Affordable Care Act.