How to Reschedule a Quest Diagnostics Appointment

You can reschedule online, by phone, or through the Quest app — the fastest route depends on how soon you need the new date

Quest Diagnostics lets you reschedule most appointments through their patient portal, by calling the location directly, or through the Quest mobile app. The online portal is usually fastest if you know which location you want and what time works for you. If you need to reschedule urgently or have questions about whether your test requires fasting or special prep, calling the location is more reliable because you'll talk to someone who can answer right away.

The process takes a few minutes either way, and you'll get a confirmation with your new date and time. If you're rescheduling because you forgot to fast before a blood test or didn't complete prep instructions, let the staff know when you contact them — they can tell you what you need to do differently for the new appointment.

Key Takeaways

• The Quest patient portal, accessible through their website or app, lets you reschedule without calling if you have your appointment confirmation number or date of birth.
• Calling the specific Quest location where your appointment is scheduled is the fastest way to reschedule if you need a date within the next few days.
• You can reschedule up to 24 hours before your appointment time at most locations, though some may allow changes closer to your appointment — ask when you contact them.
• If you're rescheduling because you didn't follow prep instructions (like fasting), tell the staff so they can confirm what you need to do before your new appointment.

Rescheduling through the Quest patient portal

Log into your account on the Quest Diagnostics website or open the Quest mobile app. You'll need your username and password, or you can sign in with your email address. Once you're logged in, look for "Appointments" or "My Appointments" — the exact wording varies depending on whether you're on the website or app, but it's usually in the main menu or dashboard.

Find the appointment you want to reschedule and select the option to change or reschedule it. The system will show you available times at that location for the next several weeks. Pick a date and time that works for you, confirm the selection, and you'll receive a confirmation email with your new appointment details. This whole process usually takes three to five minutes.

If you don't have your login information or can't find your appointment in the portal, you'll need to call instead — the portal can only show appointments you booked through Quest's system, not ones scheduled through a doctor's office or hospital.

Rescheduling by phone

Call the specific Quest location where your appointment is scheduled. You can find the phone number on your appointment confirmation, or search for the location on the Quest Diagnostics website by entering your zip code. Have your appointment confirmation number or date of birth ready when you call — the staff will use one of these to pull up your record.

Tell them you need to reschedule and what dates and times work best for you. They'll check availability and book you into a new slot. Ask them to confirm your new date and time before you hang up, and they'll usually send a confirmation email or text message within a few minutes. If you're calling during busy hours (typically mid-morning on weekdays), you may wait on hold for a few minutes.

Most Quest locations are open Monday through Friday from 6:30 a.m. to 6 p.m., and Saturday mornings, though hours vary by location. If you call outside these hours, you can leave a message and a staff member will call you back, usually within one business day.

Rescheduling through the Quest mobile app

Download the Quest Diagnostics app from the Apple App Store or Google Play Store if you haven't already. Log in with your email and password, or create an account if this is your first time using the app. Once you're logged in, tap "Appointments" at the bottom of the screen.

Find your upcoming appointment and tap on it. You'll see an option to reschedule or cancel. Select reschedule, choose your new date and time from the available slots, and confirm. You'll get a confirmation right away in the app and usually an email as well. The app works the same way as the website portal — you're just using a mobile version of the same system.

What to know about timing and cancellation policies

Most Quest locations allow you to reschedule up to 24 hours before your appointment time. If you're trying to reschedule less than 24 hours before, call the location directly — some can still accommodate you, especially if they have same-day or next-day openings. If you cancel instead of rescheduling, the same 24-hour window usually applies.

If you miss an appointment without canceling or rescheduling, Quest may charge a no-show fee. The amount varies by location and your insurance, so check your confirmation paperwork or call ahead if you're unsure. If you know you can't make your appointment, reschedule or cancel as soon as possible to avoid this fee.

Some tests require specific timing — for example, fasting blood work usually needs to be done in the morning after you haven't eaten for 8 to 12 hours. When you reschedule, make sure your new appointment time still works with any prep requirements. If you're unsure what prep you need, ask the staff when you reschedule.

If you can't reschedule online or by phone

If the portal shows no available appointments at your preferred location, try searching for a different Quest location nearby. Many areas have multiple Quest centers, and one location may have more open slots than another. You can search by zip code on the Quest website to see all nearby options.

If you booked your appointment through your doctor's office or a hospital rather than directly with Quest, you may need to reschedule through that office instead. Call the doctor's office or hospital and ask them to contact Quest on your behalf, or ask for Quest's direct number for that specific appointment.

If you're having trouble logging into the portal or the app, try resetting your password. Go to the Quest login page, select "Forgot password," and follow the steps to reset it. If that doesn't work, call the location directly — they can reschedule you over the phone and may also be able to help you troubleshoot your account access.

Frequently Asked Questions

Can I reschedule less than 24 hours before my appointment?

It depends on the location and how full their schedule is. Call the location directly and ask — they may have same-day or next-day openings available. If they can't reschedule you, ask about canceling without a fee if you genuinely can't make it.

What if I need to reschedule because I didn't fast before my blood test?

Call the location and explain that you didn't complete the prep. They can reschedule you and confirm what you need to do before your new appointment — usually fasting for 8 to 12 hours before a morning appointment. Write down the prep instructions so you don't miss them again.

Do I need to reschedule through the same place I booked?

If you booked directly through Quest's portal or app, you can reschedule the same way. If your doctor's office or hospital booked it for you, contact them first — they may need to reschedule it on their end, though some will give you Quest's direct number to call instead.

Will I be charged a fee if I reschedule?

No — rescheduling is free. You're only charged a no-show fee if you miss the appointment without canceling or rescheduling beforehand. Rescheduling as soon as you know you can't make it protects you from that fee.

What if the app or website won't let me reschedule?

Try calling the location directly — they can reschedule you over the phone in a few minutes. If you're having trouble with your account, ask the staff if they can help you reset your password or troubleshoot your login.