In its latest effort to get more states to states to expand their Medicaid programs, health officials are emphasizing its role in paying for treatment of opioid abuse and mental health issues. Federal health officials are still pressing to get more states to agree to extend Medicaid eligibility to all low-income residents under the Obama health law, in the wake of a 2012 Supreme Court decision that effectively gave governors and state legislators a choice over whether to do so. To date, 30 states have opted in; 20 are sitting out.