Patients in those states may see longer wait times both in person and over the phone, according to Kaiser. The company said it would close more than 20 of its labs, imaging centers and pharmacies in Colorado, mostly in and around Denver and Boulder. Some labs in California said they were only open for urgent issues, while some outpatient programs in Oregon are temporarily closed.

With over 12 million patients, Kaiser operates 39 hospitals and more than 700 medical offices in eight states and D.C. The vast majority of striking workers — over 60,000 — are based in California, where Kaiser is headquartered, according to a union fact sheet.