An insurer that bids on a contract subject to the competitive bidding and competitive proposal requirements adopted under Section 252.021, Local Government Code, may not submit a bid for a contract to provide stop-loss or other insurance coverage that is subject to any qualification imposed by the insurer that permits the insurer to modify or limit the terms of insurance coverage to be provided after the contract has been made. An insurer that provides stop-loss or other insurance coverage for health benefits under a contract subject to this subchapter may not, based on an individual’s prior medical history: exclude from coverage an individual who is otherwise eligible for the health benefits coverage; or assign a higher deductible to the individual.