A large tie-dye-painted van parked in the Tenderloin aims to cut ambulance calls to the neighborhood and emergency room visits by treating complaints, like wounds, rashes and the common cold.

Nonprofit HealthRight 360 will officially unveil its splashy, brightly colored mobile clinic Tuesday. The van, which has two small examination rooms, provides basic primary care services to the city’s homeless. The goal is to reduce 911 calls, improve care and save the city money by treating people before they’re so sick they wind up in the emergency room.

“Our hope is that we can meet people where they are,” said Ana Valdés, chief health care officer of HealthRight 360. “If we can catch issues early on, then they won’t need to go to the emergency room. And if we can help them, they won’t have to call 911 for issues that are handled at the van.”

The van is restricted to addressing acute needs and basic preventive care, like wrapping wounds, checking blood pressure and TB testing, and providing primary care, like high blood pressure and diabetes. That’s a fraction of the services that the city’s thousands of homeless, mentally ill and drug addicted actually need. Still, it is a step toward improving access to the city’s health care. The nonprofit also plans to expand services to eventually include medication-assisted treatment for addiction, behavioral health services and rapid HIV testing.

By making access to basic medical care easier, the city could reduce the number of ambulances rushing through the Tenderloin, said Del Seymour, a longtime neighborhood advocate. Not only does an ambulance transport cost thousands of dollars, the city’s emergency rooms are already overwhelmed with the number of people coming in off the streets.

“The EMS (emergency medical services) should just park in front of Glide (Memorial Church) to save gas,” he said, of the church on Ellis Street where many homeless people congregate. “Many need help, but they don’t necessarily need an ambulance. Most of the issues can be take care of with some Motrin and a rewrap of a wound.”

HealthRight 360’s van has been parked outside Glide Memorial Church since September. The nonprofit was testing the service twice a week from 11 a.m. to 3 p.m. So far the clinic has helped 125 people for a range of issues, from abscesses to low blood sugar and hypertension. While the nonprofit says it won’t turn anyone away, it generally serves people who are homeless.

The mobile service was created after HealthRight 360 had to shut down its facility — Tenderloin Health Services — inside the church earlier this year, as it couldn’t find or retain the staff needed to operate the facility. San Francisco and other major cities around the country have struggled to attract health care workers as the cost of living soars and wages stagnate.

HealthRight 360 is operating its van with existing staff members. It is also recruiting for five positions dedicated to the van.

While the van is a slimmed-down version of the brick-and-mortar clinic, the nonprofit plans to expand the mobile service to five days a week in January. Eventually HealthRight 360 plans to move it around to other neighborhoods with high homeless populations, like the Haight-Ashbury.

The van is the San Francisco community’s latest attempt to expand services to people on the streets. It has also grown its Homeless Outreach Team to connect more people with services. Meanwhile, a free clinic in the Haight-Ashbury, which was considered a national model for free health care and substance use treatment, shut down earlier this year as it became financially unfeasible.

HealthRight 360 raised $650,000 from private donors to pay for the van’s startup and operation costs for the first three years. The nonprofit intends to continue fundraising from private donors to continue operating — and possibly expand — the service. Sutter Health California Pacific Medical Center, Veritas Investments (one of the city’s largest landlords) and Wells Fargo also contributed.

“A lot of times we see clients from the Tenderloin and Haight-Ashbury come in with more progressed conditions, both medical and behavioral, in the emergency room,” said Emily Webb, director of Community Benefit in the Bay Area for Sutter Health, which donated $250,000 to help fund the van. “We’re interested in investing in having people be healthier and get the services they need sooner.”

Still, the van and its two exam rooms have major limitations when it comes to helping the city’s swelling homeless, drug addicted and mentally ill population. Often the biggest hurdle to getting care is a lack of transportation to the city’s many different drug treatment programs.

The van cannot seamlessly connect people to drug treatment services. Someone who wants to go into a residential treatment program will still have to go to HealthRight360’s headquarters on South Van Ness Avenue and go through an arduous intake process that could take hours.

And even if addicts make it to the intake, there is no guarantee they will get the help they want that day: The city’s treatment programs are often full, or don’t have enough staff to operate all the beds. The city is adding hundreds more treatment beds, but people are now left on the streets every night without adequate care.

Still, bringing primary care to people— rather than expecting them to find their way to a facility — could make a difference in how and when people get help, said Lizz Cady, a social worker in the city. This could reduce the number of people who wait for a medical condition, like an infection, to get dire before seeking help.

The staff in the mobile unit can refer clients to treatment, answer questions about other services and coordinate a drug treatment intake. And communication also gives staff the ability to build trust with people on the streets.

“Even if they just come in and have their wounds taken care of with dignity and respect, that alone increases the likelihood of them seeking out more care,” she said.

Trisha Thadani is a San Francisco Chronicle staff writer. Email: tthadani@sfchronicle.com Twitter: @TrishaThadani

About the Broken Care series San Francisco spends nearly $400 million a year on mental health and addiction treatment, but thousands of people in crisis are still without sufficient care. In this ongoing series, Chronicle journalists investigate the failures of this complicated, costly system and explore solutions to the crisis.