Escalating medical and prescription drug costs have given Regence BlueCross BlueShield executives little choice but to raise rates an average 9.6 percent for people who buy their own insurance, an executive told Oregon insurance regulators Monday.

“We are simply putting our finger in the dam and hoping that the water stops flowing,” said Don Antonucci, Regence’s Oregon president, adding that the insurer is spending down reserves to limit increases.

The rate hike and a new, more limited provider network for about 20,000 Portland-area members were discussed at a sparsely attended public hearing in Salem.

Regence unveiled the changes, which affect only people who are not on Medicare, in June. Portland-area members must choose between five provider networks, each one affecting premiums differently: Providence Health 15.3 percent; Oregon Health & Science University 12.2 percent; Legacy Health 11.2; percent Tuality Health 6.7 percent; Adventist Health 2.6 percent.

Regence officials say many people will actually see their premiums go down because the insurer is transferring people from low-deductible plans to higher ones.

However, at the hearing, critics attacked the proposal as well as its effects.

Jesse Ellis O’Brien of the OSPIRG Foundation said Oregonians will face less choice and more costs as a result of the proposal.

 “Just because it can be done doesn’t mean it should,” said Gillian Hearst of Stayton, adding that Regence has “lost sight of its origin which is helping people, not making profits.”

The public has until Aug. 4 to submit written comments to the Oregon Insurance Division, or comment online at The Oregon Insurance Division is expected to decide on the request shortly thereafter.