If your provider has ordered INR monitoring, this guide explains the visit options and how to prepare according to their instructions.
What is being measured
A PT test measures how long your blood takes to clot. The result may be reported as an INR, which helps your healthcare provider compare results from different laboratories or testing methods. If you take warfarin, your prescribing provider or anticoagulation clinic sets your testing schedule and decides whether your dose needs to change.
How to prepare
There is no general fasting requirement for an INR check. What matters is consistency: take your dose at your usual time, and keep your appointment window consistent between checks if your clinic asked you to. Do not skip or shift a dose to prepare for the visit unless your prescriber told you to.
- Bring or note any recent changes: new medications, antibiotics, illness, or a significant change in leafy-green intake.
- Tell us if your clinic asked for the check at a specific interval after your dose.
- Keep your dosing log handy if you keep one.
At the visit
We confirm your identity and check your provider’s order before testing or collecting your sample.
When we perform PT/INR testing during your visit, it falls under Stumptown’s CLIA Certificate of Waiver. If your order calls for laboratory testing, we collect your sample and send it to the laboratory named on the order.
Results go to the provider or anticoagulation department listed on your order. They decide whether your medication dose needs to change. Stumptown does not make dosing decisions.
Clark County patients
If your prescriber is in Washington, make sure the order names the Washington provider or anticoagulation department that should receive the result.
Recurring visits and pricing
Your first qualifying monitoring visit in a calendar month is billed at the standard rate. When you book another monitoring visit for the same month, the lower repeat rate applies only if an earlier eligible visit for the same patient has already been completed and its payment is paid or authorized. A future appointment does not qualify, even if its payment is paid or authorized. Eligibility is checked automatically when you book, using Pacific Time to determine the calendar month.
Common questions
- Do I need to fast for an INR check?
- No, there is no general fasting requirement. Keep your warfarin dose at its usual time unless your prescriber instructed otherwise.
- Who gets my result?
- The provider or anticoagulation department named on your order. They make any dosing decision — Stumptown does not interpret results or adjust doses.
- How much does a recurring visit cost?
- The first qualifying monitoring visit in a calendar month is billed at the standard rate. To receive the lower repeat rate when booking another visit for that month, the same patient must already have an eligible completed visit that month with payment paid or authorized. Future appointments do not qualify. Calendar months are based on Pacific Time.
- Can you come to a care facility?
- Yes. Recurring multi-patient facility routes are scheduled directly rather than as individual appointments.
Stumptown Mobile Lab Services performs specimen collection, handling, processing where applicable, and delivery or shipment. Laboratory testing and laboratory-reported results are provided by the applicable testing laboratory, except for our specifically identified CLIA-waived point-of-care testing services. Nothing here is medical advice — questions about your care belong with your provider.