Californians stricken with COVID-19 took the first step in filing more than 5,000 workers’ compensation claims from January through May, according to state data released to CalMatters.

More than 1,000 of those claims were denied, most of them before Gov. Gavin Newsom signed a May 6 executive order extending protections for essential workers infected on the job on or after March 19, the day California’s lockdown order went into effect. The order presumes that essential workers – including nurses, first responders, farmworkers and grocery workers who contracted COVID-19 – were infected on the job, and puts the burden on employers to prove otherwise.

At the same time, overall workers’ compensation claims plummeted during California’s lockdown as workplaces shut down and fewer employees were injured at work. Only 1,098 claims were filed in May, compared with more than 50,000 in January.

While a number of states have extended similar “presumptive eligibility” protections to varying groups of workers – mostly health care workers and first responders – California goes further than many in protecting all essential workers.

As of Tuesday, more than 10,000 health care workers have been diagnosed with COVID-19; 63 have died. More than half worked in nursing homes.

Analysts originally estimated that California employers and their insurers might face COVID claims of up to $33.6 billion annually but later downgraded that to about $2 billion.

COVID-related claims were denied at a rate of 10 to 60 percent depending on the month. In April, about 13 percent of claims were denied. Under Newsom’s executive order, essential workers, such as nurses or first responders, have to show that they were infected within a certain period after the statewide shutdown began; they also had to be diagnosed by a physician.

Alex Swedlow, president of the California Workers’ Compensation Institute said that even before Newsom’s order took effect, the majority of COVID claims were approved.

The shortage of diagnostic tests – a significant problem for workers in March and April, when most of the claims were filed – may have contributed to some of the denials, Swedlow said. Other workers may have been denied because they tested negative at a time when some COVID-19 tests have produced false negatives.

An Institute report released earlier this month found that about 41 percent of workers’ comp claims were made by health workers, with another 32 percent by first responders including police and firefighters. Some workers were denied because they worked at home; others because they declined to be tested, according to the report.

Swedlow anticipates that denials may decline as workers get more access to testing and California’s workers’ comp system adjusts to dealing with an entirely new disease.