PT/INR Test Cost and Medicare Coverage (CPT 85610)

Also called: PT test · INR test · protime · clotting time test — all the same test, CPT 85610.

The short answer

Yes — this is one of the most reliably covered tests in medicine. Medicare’s national policy (NCD 190.17, the same in every state) covers the PT/INR for its main real-world job — monitoring the blood thinner warfarin (Coumadin) — plus bleeding problems, liver disease, and pre-surgery checks. People on warfarin get this test constantly, sometimes weekly, and that’s fine: the frequency follows medical need, and dose management is exactly what the policy exists for. Medicare pays the lab $4.29 per test.

When Medicare DOES cover it

• Warfarin monitoring — the big one. Every dose adjustment and routine check while on the medication is covered as often as your management genuinely requires.
• Evaluating bleeding or clotting problems — unexplained bleeding, easy bruising, suspected clotting-factor disorders
• Liver disease — the liver makes clotting factors, so PT doubles as a liver-function signal
• Before surgery or procedures when bleeding risk needs checking

When Medicare does NOT cover it

• Routine screening with no medication, symptom, or condition behind it — rare in practice for this test.
• One technical note from the national policy: the PT is the warfarin test. Patients on heparin are monitored with a different test (the PTT) — mixing those up on an order is a paperwork problem, not a you-problem, but it explains some odd denials.

What you pay if it IS covered: $0

Covered lab tests cost Medicare patients nothing — no deductible, no 20% coinsurance. Medicare pays the lab $4.29, and you owe zero — even when you’re tested every week.

What it costs to buy yourself

The PT/INR sells direct-to-consumer for $10 at Jason Health (jasonhealth.com — add their flat $18 lab-collection fee per order), about $39 at Labcorp OnDemand, and $42 at Quest’s consumer site (questhealth.com, plus a $6 physician fee). Worth knowing — though if you’re on warfarin, your monitoring should be running through your doctor and Medicare at $0, not out of pocket.

What counts as a “normal” INR result

This is the one test where “normal” is the wrong word. If you take warfarin, the point of the test is not to land in the range a healthy person would occupy — it is to sit inside a target range your doctor sets deliberately, to keep your blood thinner than usual without going too far.

That target is chosen for your situation: the reason you are on warfarin, your other conditions, and your history all move it. Two people on the same medication can be given different targets, and yours can be changed over time.

So there is no general figure worth printing here. The number that applies to you is the target your own doctor has set, and your result is read against that, not against a population range.

(Where lab ranges and “optimal” ranges come from, and who decides.)

This page can tell you where those numbers came from. It cannot tell you what yours means — that reading belongs to your doctor, alongside your history and your other results.

Quick questions people ask

What is a PT/INR test? The prothrombin time (PT) measures how many seconds your blood takes to clot. The INR is that result standardized so it reads the same at every lab in the world — which matters because warfarin doses are set by INR targets (commonly 2.0–3.0). One blood draw produces both numbers. On billing paperwork it’s CPT code 85610.

Is PT the same as PTT or aPTT? No — they’re partner tests that check different parts of the clotting system. The PT (this page) monitors warfarin. The PTT or aPTT monitors heparin and screens other clotting factors — a separate test with its own code, coverage rule, and price. Some orders include both when a bleeding workup is underway, though for monitoring one blood thinner Medicare’s policy expects one test, not two.

How often will Medicare pay for it? As often as your care truly requires — weekly INRs during a dose change are normal and covered. One convenience worth asking about: Medicare also covers home INR monitors for certain long-term warfarin patients, so ask your doctor if finger-stick testing at home fits your situation.

Do you have to fast for a PT/INR test? No. Fasting isn’t required, and you should take your blood thinner as usual unless your doctor tells you otherwise, because the test measures how well that dose is working. Our fasting guide covers which tests do need it.

Sources and data dates

Medicare payment amount: CMS Clinical Laboratory Fee Schedule, 2026 Q3 file (national rate). Coverage rules: CMS Medicare Coverage Database, NCD 190.17 (Prothrombin Time) — a national policy, identical in every state. Consumer prices checked September 2026. Information current as of the date shown above; coverage is always determined by Medicare when your claim is processed.

ClaraCover provides information, not medical, billing, or insurance advice. Talk to your doctor about what tests you need.