(KXAN) — As more and more businesses nationwide implement proof of vaccination for customers to enter, so too is the number of employers requiring it for workers.

Top job site Indeed reports that as of August 7, there’s been a 90% rise in job postings per million requiring vaccinations. It’s important to note that some businesses list “vaccinations” as a requirement, while some explicitly list “COVID-19 vaccination” as a requirement — but it’s completely within a business’ purview to require either.

And while the the Health Insurance Portability and Accountability Act of 1996 — better known as HIPAA — protects health care professionals and certain organizations from having to disclose a person’s vaccination information, HIPAA does not bar private businesses from asking for it. It also doesn’t give an employee or potential employee from having to give it to keep or get a job.

The Equal Opportunity Commission says while federal laws don’t prevent businesses from requiring COVID-19 vaccinations for employees, under the Americans With Disabilities Act, certain accommodations must be made if employees have certain circumstances making it more difficult for them to get vaccinated.

Among the challenges for managers who would hire unvaccinated (by choice) workers include opposition and concern for the health of other employees and attempts to juggle accommodations to keep unvaccinated and vaccinated employees apart.

These requirements are already being seen in many businesses including in the federal government, where President Joe Biden has already implemented required proof of vaccination. Under the mandate, employees could face fines and/or imprisonment for lying about their status.

Companies that are already requiring certain employees to show proof of vaccination include Google, Facebook, Disney, Ascension Health, and Walgreens.

Meanwhile, areas like New York City and San Francisco have gone even over the head of business owners: passing orders that require residents to prove vaccination to partake in indoor activities, including eating in restaurants and working out in gyms.

According to Indeed info, in July, the sectors that saw the biggest increase in vaccine requirements to apply include education, food preparation and service, drivers, and loading and stocking.