For Rachel Robles, getting diagnosed with Long COVID was an uphill battle. She caught the virus in March 2020, when nearly nothing was known about its long-term effects and testing was inaccessible for most people.

To this day, she is sensitive to looking at screens—doing so can prompt pressure in her head and ringing in her ears—and has to manage COVID-19-related injuries to her liver and brain. But since she never got tested for COVID-19 when she first got sick, Robles had to “fight tooth and nail for every diagnosis I’ve received,” convincing doubtful doctors that she’d caught the virus and developed Long COVID.

She was eventually diagnosed with Long COVID, but it likely would have been easier if she had had the proof of infection that a test result provides, she says. Robles now recommends that anyone who suspects they have COVID-19 get a laboratory test, just in case they go on to develop Long COVID and need documentation of a previous infection for diagnosis or care.

“I never got proof of my initial COVID infection, and I was gaslit so much,” says Robles, who is an administrator at the Long COVID support group Body Politic and a contributor to the Patient-Led Research Collaborative for Long COVID. “So I always tell people, ‘This is something you need to do if you have a COVID infection, just in case.’”

David Putrino, a Long COVID researcher at New York’s Mount Sinai health system who co-authored a chapter of the forthcoming Long COVID Survival Guide with Robles and neurologist Dr. Dona Kim Murphey, says he “wholeheartedly” agrees that people should get as much documentation of an infection as possible. Getting a PCR test is “100% the recommendation”—but if all you can do is take an at-home test, at least keep photos of the results, Putrino says.

“Covering your bases as soon as you start to feel unwell and keeping good records is super important,” he says. (In the book chapter, Putrino, Murphey, and Robles even recommend that people consider getting blood tests and chest X-rays done soon after they get diagnosed with COVID-19, so they have a baseline record in case they later experience complications.)

PCR tests are still considered the gold standard for accuracy, so some doctors recommend getting one to confirm the results of an at-home swab. But people are increasingly forgoing that step now that rapid tests are widespread and increasingly accepted. A PCR test isn’t even required to get a prescription for the antiviral Paxlovid.

It may seem paranoid to plan ahead for a possible case of Long COVID—but the odds of getting it aren’t so long. Recent federal data suggest that one in five people who catches COVID-19 will develop symptoms of Long COVID, which can include fatigue, cognitive dysfunction, and chronic pain, among many others.

If someone does develop Long COVID, having documentation of a previous COVID-19 case could make it easier to get properly diagnosed or treated in a Long COVID clinic, some of which require either proof of previous infection or a positive antibody test. But not all patients have such proof.

In July, Hannah Davis—who is also part of Body Politic and the Patient-Led Research Collaborative for Long COVID—said in Congressional testimony that PCR and antibody tests “are often required for sick leave, entry into Long COVID clinics, health care, and participation in research,” even though some people get false negative results and others can’t get tested at all. Davis added that some people who catch COVID-19 do not produce antibodies, or see their antibody levels drop to undetectable levels over time.

Dr. Hector Bonilla, who co-directs Stanford’s Post COVID-19 Syndrome Clinic, says his facility accepts a patient as long as they have a positive test result linked to their name—that is, one done by a clinician or testing service, as opposed to a do-it-yourself home test—or evidence of infection-related antibodies. Having a COVID-19 test result can help determine whether someone has Long COVID or other, similar illnesses, such as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), Bonilla says. (Some Long COVID patients also meet diagnostic criteria for ME/CFS.)

But Dr. Benjamin Abramoff, who directs Penn Medicine’s Post-COVID Assessment and Recovery Clinic, says he thinks fewer clinics will require official test results now that at-home tests are the norm. “Realistically, everybody’s going to be getting home tests,” he says. “I can’t imagine anyone requiring [formal testing] moving forward.”

And while many Long COVID patients without PCR test results were outright dismissed by doctors early in the pandemic, Abramoff thinks that’s happening less now that Long COVID is more widely known. “It still happens, but much less than it did,” he says. Even without a PCR test result, documentation from a doctor can be enough to get disability benefits, insurance coverage, and work accommodations, he says. Many long-haulers struggle to get disability benefits even with proper documentation, however.

Maria Van Kerkhove, the World Health Organization’s (WHO) technical lead for COVID-19, said in a statement to TIME that “the lack of proof of prior infection shouldn’t be an impediment for people to get access to diagnosis and care” for Long COVID. The WHO’s definition of Long COVID specifies that it can occur among people who have either a “probable or confirmed SARS-CoV-2 infection,” she noted.

Still, Putrino says it’s better to be safe than sorry, as the criteria for getting a Long COVID diagnosis or being admitted to a treatment center vary by institution and could change in the future. “Those diagnostic criteria can change based on who’s in power,” he says. “Making sure that you have very clear documentation of a positive test is important, because it gives you your best chance of being able to receive services as long as you need them.”