What is hs-CRP?
hs-CRP stands for high-sensitivity C-reactive protein. It’s a blood test that measures inflammation, and it’s used for one fairly narrow purpose: helping estimate your risk of heart disease.
The short version
- CRP is a protein. In the words of the National Library of Medicine, “Your liver makes CRP in response to inflammation.”
- “High-sensitivity” refers to the assay, not to your result. It measures very small changes that a standard CRP test isn’t built to detect.
- Same substance, different jobs. A standard CRP test looks for infection and inflammatory illness. The hs-CRP version is used to estimate heart disease risk.
- The big limitation: CRP shows how much inflammation you have. It does not show where it is or what is causing it.
- Medicare: this is the important part. hs-CRP is covered in essentially one narrow situation, and “routine heart check” isn’t it. Medicare pays the lab $12.95 when it is covered.
Two tests, one substance
This is the part that confuses people, and it’s worth getting straight before you look at a result. CRP and hs-CRP measure the same protein in your blood. What differs is how finely the lab measures it, and what the number is being used for.
- Standard CRP is ordered to check for bacterial infections, chronic inflammatory conditions, infection after surgery, or to monitor sepsis. It’s looking for inflammation that is substantial and usually obvious.
- hs-CRP measures, as MedlinePlus puts it, “very tiny increases in your CRP levels. It is used to estimate your risk of heart disease.”
So if you were handed an hs-CRP result, your doctor was probably thinking about your heart, not about an infection.
What makes CRP go up
The list is long, which is exactly why the number can’t stand alone. The National Library of Medicine names bacterial and viral infections, inflammatory bowel disease, autoimmune disorders, lung diseases, smoking, and exposure to environmental toxins among the things that raise CRP.
This matters for the heart-risk use in a specific way: an ordinary infection or a flare of an inflammatory condition can raise your CRP at the moment of the draw, which makes that particular result unhelpful for judging long-term heart risk. It’s one reason the test is meant to be done when you’re otherwise well.
What a high result can and can’t tell you
MedlinePlus is direct about the ceiling on this test: it indicates “how much inflammation you have in your body” but does not identify the cause or the location. A high CRP says something is inflamed. It does not say what, or where, or why.
High levels, the National Library of Medicine notes, “may mean you have an acute or chronic health condition” — infections, inflammatory bowel disease, autoimmune disorders, and lung diseases among them.
We don’t print a normal range here, and with this test there’s an extra reason beyond the usual one. Labs differ, as always. But hs-CRP results are also grouped into risk bands rather than read as a simple in-or-out-of-range number, and which band matters depends on the rest of your cardiovascular picture. That reading belongs to your doctor, with your result in front of them. Why that range is not the whole story →
What Medicare pays — read this before you agree to the test
hs-CRP is marketed almost everywhere as a routine “inflammation and heart health” number, and it appears in a great many wellness panels. Medicare’s regional policies take a much narrower view, and the gap between the two is where people get surprise bills.
The covered use is essentially a single scenario: your doctor is deciding whether to start cholesterol-lowering medication, your 10-year heart risk sits in the intermediate zone, and the hs-CRP result would genuinely tip that decision. One time. Not for monitoring, not for an annual heart checkup, and not as part of a wellness panel.
| Test | Code | Medicare pays the lab | You pay if covered |
|---|---|---|---|
| High-sensitivity CRP | 86141 | $12.95 | $0 |
If you’re handed a form to sign before this test, that’s the lab telling you it expects Medicare to say no. That form is worth understanding before you sign it. What to do before you go →
The hs-CRP test page has the full coverage rules and what it costs to buy directly. hs-CRP cost and Medicare coverage →
Sources
- MedlinePlus (National Library of Medicine): C-Reactive Protein (CRP) Test
- Medicare coverage detail: regional policy LCD L34856
- Medicare payment amounts: CMS Clinical Laboratory Fee Schedule, 2026 Q3
Checked September 23, 2026. This page explains what the test measures. It is not medical advice and cannot interpret your result. Your doctor can.
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