BOSTON — Medical marijuana is pouring money into the state’s coffers, as the number of pot patients and dispensaries grow.

The state raised more than $7.2 million in the past fiscal year from marijuana dispensary fees and applications, as well as patient registration fees, according to the Department of Public Health. The four-year-old program spent just $2.8 million on salaries and related expenses.

Next year, the health department expects nearly double the revenues from the medical pot program, as well as $5 million in funds rolled over from the previous year. The money is kept in a trust fund used to cover operating expenses for the program.

Meanwhile, the number of people using marijuana to treat chronic pain, cancer symptoms and other conditions continues to grow.

At least 39,778 patients were certified to buy medical marijuana in February, according to the health department, up from nearly 24,196 a year ago.

In February, patients bought 15,320 ounces of marijuana from 10 dispensaries. That’s a sizable increase from 5,866 ounces sold in February 2016.

More physicians are signing up to recommend marijuana treatment, and more “caregivers” are being licensed to provide patients with marijuana.

To get medical pot, patients must have a doctor’s recommendation and a state-issued license, and they must be vetted by health officials. They’re also required pay a $50 annual registration renewal fee.

The state also caps how much pot a patient can get at 10 ounces over a 60-day period.

Voters in November 2012 overwhelmingly agreed to allow as many as 35 dispensaries to grow and sell marijuana for patients with conditions such as cancer, multiple sclerosis and Parkinson’s disease.

Delays in launching the program led to an outcry from medical marijuana advocates. In 2015, the state streamlined the process to allow dispensaries to win approval more quickly, in a way similar to how health care facilities are licensed.

The program also added new staff, growing from nine full-time employees in fiscal 2016 to 19 this year. The state runs a call center to register patients, caregivers who are allowed to provide medical marijuana, as well as dispensary employees.

“It wasn’t a smooth rollout, but it’s starting to get traction,” said Nichole Snow, director of the Massachusetts Patient Advocacy Alliance. “The state doesn’t want this program to be an embarrassment.”

The health department is considering a slew of changes to streamline the approval processes, clarify language and improve patient access and public safety.

Snow said the state should consider eliminating the $50 fee for patient registration cards, which causes a financial hardship for some.

Advocates said a lengthy approval process for new dispensaries is also keeping people from getting their medicine.

Some patients struggle to pay for marijuana treatments that average $300 per ounce, since insurers don’t cover it.

Dr. Uma Dhanabalan, of Uplifting Health and Wellness in Natick, is one of 183 physicians registered to recommend marijuana to treat a range of illnesses. She said many people are still unable to get medicine, either because of a lack of supply or a lengthy distance from the dispensaries that have opened.

Health officials are considering 95 applications for new dispensaries, several of which are likely to be approved. Regulators eventually expect at least 98 percent of the population will live within 25 miles of a dispensary, based on actual and proposed locations.

To date, the state has licensed 10 dispensaries — including Alternative Therapies Group in Salem. Others have been issued in Lowell, Ayer, Northampton, Brookline, Quincy, Brockton and Cambridge.

Happy Valley Ventures in Gloucester and Healthy Pharms in Georgetown are also planning to open new facilities. Three medical marijuana dispensaries have submitted proposals in Methuen.

Dispensaries and growing facilities that supply medical marijuana pay application and licensing fees from $1,500 to $50,000. And some communities are pushing back against proposed dispensaries by passing moratoriums and zoning laws restricting where they can locate.

“Unfortunately there is a lot of stigma about medical marijuana in some communities,” Dhanabalan said. “And that’s alienating people who are seeking medical treatment.”

Christian M. Wade covers the Massachusetts Statehouse for North of Boston Media Group’s newspapers and websites. Email him at cwade@cnhi.com.