Check the airline, and of course, check the Safe Travels Hawaii site for the list of approved labs. If you do it the right way, you're pretty much guaranteed to get the results back in time. If you just go into your local testing site for a test, you may not, or you may not get the official Hawaii results form that is necessary for the (automated) Safe Travels approval.
The best site when we went last month was the Color site near SFO, which we did three days before our flight. You need to make a reservation for the test, and we got our results back in about 12 hours, though it can take up to 24. Make sure you don't get tested any earlier than 36 hours before your flight to Hawaii departs (if you're connecting, the relevant time is when the flight TO HAWAII departs, not your first flight to wherever you're connecting.) Even one minute earlier will cause your test to be invalid for the quarantine exemption. For example, if your flight to Maui from SFO leaves on Friday at 9:30 am, don't get tested before 9:30 AM on Tuesday.
The Color site is a drive-through site and was quick, organized and easy. I think it was $105 per person. I do not believe any of the sites for travel testing will be covered by insurance; in fact, I'd say if they even ask for your insurance info, you probably aren't getting a test that will be accepted by Hawaii. There were people on our flight who screwed up and had the wrong test and had to turn around and fly home.
United also has rapid testing which you can do at the airport prior to your flight by arriving a bit early. It was more expensive ($140? I forget) and we opted for the earlier test. You can also do mail in testing from Costco (you buy the test kit, then 3 days before your flight you do your own nasal swab while a clinician watches you by video link from your phone, then you return it by overnight UPS that same day and you get your results probably the day before your flight. That probably works fine but it seemed like there were too many things that could go wrong there.
The day before your trip you need to upload the test results and fill out a health questionnaire on the Safe Travels site, to get the all-important QR code that will let you bypass quarantine. When you get to the airport, make sure you do the pre-travel clearance (check your airline's web site for info) which will allow you to avoid a multi-hour line in Maui.
Have a great trip!
