In 2015, Governor Fallin signed HB 2154, Katie and Cayman’s Law, which allows physicians in Oklahoma to recommend a high-CBD cannabis oil (less than 0.3 percent THC) to minors suffering from a severe epilepsy disorder such as Lennox-Gastaut or Dravet Syndrome. In 2016, the state adopted HB 2835, which expanded legal protections to patients of all ages and added several new qualifying conditions including spasticity due to Multiple Sclerosis or paraplegia, intractable nausea and vomiting, and appetite stimulation with chronic wasting diseases. In March of 2017, a lawsuit was resolved allowing Question 788 - the Medical Marijuana Legalization Initiative to appear on the June 2018 Ballot, where voters approved the initiative by 57 percent. 

Under Question 788 registered patients may possess up to three ounces of medical cannabis flower and one ounce of concentrated medical cannabis and may also cultivate up to six mature plants with another six vegetative plants.  Regulations governing the operation of the new law were approved quickly in 2018, which also removed the ban on smoking cannabis as a treatment method, the requirement that all dispensaries have a pharmacist on staff and the patient eligibility condition list.  That same year the Oklahoma Court of Civil Appeals ruled that the presence of an intoxicating substance in the blood does not automatically mean impairment, which is a victory for those patients who may be drug tested in the workplace. The Oklahoma Medical Program grew rapidly in 2019, as no licensing caps were imposed on medical retail facilities.  By the beginning of the fourth quarter of 2019, state regulators had issued almost 7,000 licenses to cannabis businesses and registered over 200,000 patients.  

2019 saw Oklahoma implement a number of new reforms to the state’s medical access program.  Included in these reforms were reduced application fees for low-income patients, an expansion of the type of licensed physicians who may recommend medical cannabis and organization of guidelines for inventory testing, tracking, advertising, packaging and labeling.  Lawmakers also approved HB 2612, which establishes a Medical Marijuana Authority within the state Department of Health, outlines the rights of patients who are firearm owners, allows patients to have 2-year registrations, permits veterans to participate in the program and creates a medical cannabis research licensing category.