What is the normal range for hepatitis B surface antibody?

It is better thought of as a threshold than a range, because the guidance states a floor with nothing above it. CDC treats anti-HBs at 10 mIU/mL or above, measured one to two months after a completed vaccine series, as documenting vaccine-induced protection. Labcorp reports its reference interval as immunity above 10.0 mIU/mL. There is no upper limit in any of these sources, so a result in the hundreds or above a thousand is a strong response rather than an abnormality. Laboratories do differ near the line: the University of Washington cites a protective level of 12 mIU/mL or above per the manufacturer's package insert, and the University of Iowa reports three tiers — non-reactive below 8.5, indeterminate from 8.5 to 11.5, and reactive at 11.5 or above. The reference information printed on your own report is what applies to your number.

My hepatitis B surface antibody is low — what does that mean?

It means protection is not documented by this test, which is narrower than being unprotected. What follows depends on your vaccination record, and the decision belongs with your clinician. If you recently finished a series, the measuring window is one to two months after the last dose, and a result below 10 there has two acceptable routes in ACIP's recommendations: a second complete series followed by testing, or a single additional dose followed by testing one to two months later — route and schedule by product. Non-response is defined only after two complete series with infection excluded, not by a dose count. Never vaccinated or an incomplete series points to starting or completing one. And if your records show a previous anti-HBs at or above 10 after a completed series, a low number now is a declined level in a documented responder. For an immunocompetent person, CDC's Pink Book states immune memory remains intact for more than thirty years and that such recipients remain protected. Two groups differ even so: dialysis patients, for whom annual testing is advised with a booster below 10, and immunocompromised people, who "might need annual testing".

What does a result of less than 5 mIU/mL mean?

A result written as <5 reports a concentration below 5 mIU/mL. It is the laboratory's reporting convention rather than a precise figure, and what it means analytically — whether 5 is a detection limit, a quantification limit, or simply the lowest value that laboratory prints — is established by that laboratory's own assay documentation, not by the number itself. Clinically it sits where any result below the threshold sits: protection is not documented by this test. It is worth separating from a figure just under 10, which is genuinely borderline and assay-dependent — the University of Iowa reports an indeterminate band from 8.5 up to 11.5 mIU/mL, and <5 is well below that zone. What follows depends on your vaccination record: never vaccinated or an incomplete series points to starting or completing one, while a documented prior response at or above 10 puts a low number now in the waning category instead.

Is a high hepatitis B surface antibody level bad?

No. There is no upper threshold for this antibody in any current guidance — CDC states 10 mIU/mL or above as a floor and names no ceiling, and Labcorp's reference interval is simply immunity above 10.0 mIU/mL. A result in the hundreds or above a thousand is a strong antibody response, which is the outcome a vaccine series is meant to produce. One published laboratory scheme grades anti-HBs above 100 mIU/mL as a good response and gives the same management advice whether the figure is 101 or 10,000. If your result is flagged high, that flag comes from the upper bound stored for the marker rather than from anything clinical. Two caveats remain regardless of how high the number is: it does not distinguish vaccine-induced antibody from antibody left by a resolved infection, and Labcorp notes on its own assay that the presence of anti-HBs is not an absolute indicator of resolved infection nor of protection from future infection.

Does this test show whether I have hepatitis B?

No, and this is the one thing on the page worth being certain about. Anti-HBs is the immunity marker. The infection markers are HBsAg, the surface antigen, which indicates current infection, and total anti-HBc, the core antibody, which indicates past or present infection. A person can have a reassuring anti-HBs result and an active hepatitis B infection is not ruled out by it, because the two questions are answered by different tests. CDC's 2023 recommendations put all adults aged 18 and over on once-in-a-lifetime screening using all three together — HBsAg, anti-HBs and total anti-HBc — precisely because no one of them answers the whole question. If you are worried about an exposure or about infection rather than about documenting immunity, the antigen and core antibody tests are the ones to ask about.

How can I tell whether my antibody came from the vaccine or from a past infection?

Not from this number, which is identical either way. The test that separates them is total anti-HBc, the core antibody, because hepatitis B vaccines do not produce it — only infection does. Positive anti-HBs with negative total anti-HBc is the pattern of vaccine-induced immunity. Positive anti-HBs with positive total anti-HBc, and HBsAg negative, is the pattern of an infection that resolved. Both leave you with antibody, and both are reported as a number in mIU/mL on this test. The distinction matters for more than curiosity: a proof-of-immunity request is asking about the vaccine pattern, and a resolved infection carries its own follow-up considerations. In practice, your documented vaccination history plus the core antibody result is what settles it.

Do I need a booster if my level has dropped below 10?

For an immunocompetent adult who has documented a response — an anti-HBs at or above 10 recorded after a completed series — generally not. CDC notes anti-HBs concentrations might wane among responders, and its Pink Book states that in immunocompetent recipients immune memory remains intact for more than thirty years following immunization and that those whose antibody has declined remain protected against significant infection. So the protection is not in doubt across the timescales studied; the open question is the ultimate endpoint rather than whether decades of protection exist. CDC also states that routine serologic testing to assess immune status in vaccinated people is not recommended, which is why a declining number in a documented responder does not usually generate any action. The picture differs if a response was never documented in the first place, or if you are immunosuppressed, on dialysis, or in an occupational program with its own schedule — those follow specific protocols rather than this general answer.

I need to prove hepatitis B immunity for work or school — is this the right test?

Yes, and the quantitative version is often the one asked for, because it supplies a concentration that can be compared directly against a stated threshold. A qualitative classification carries a cutoff of its own and some reports give both a word and a number, so the question is what the requesting institution accepts, worth checking before chasing a repeat test. One caveat: immune globulin supplies anti-HBs passively, and CDC states testing within six months of it "is not an accurate measure of a person's immune status". What makes the documentation hold up is the pairing: the result together with the vaccination history it is read against. Anti-HBs at 10 mIU/mL or above alongside a documented complete series documents vaccine-induced protection. The same figure with no vaccination record is equally consistent with a past infection, which this number cannot distinguish. Timing matters too — CDC's window is one to two months after the last dose of the series, and measuring sooner can understate the response. If the body asking for proof specifies its own threshold, that figure rather than a general one is what you need to meet, so it is worth checking what they have asked for.

What is the difference between this test and hepatitis B surface antigen?

One letter, and opposite meanings. Surface antibody — anti-HBs, this test — is made by your immune system and indicates immunity, from a vaccine or from a resolved infection. Surface antigen — HBsAg — is part of the virus itself, and its presence indicates current hepatitis B infection, acute or chronic. They are easy to confuse on a report because the names differ by so little, and the consequence of confusing them is large: a positive antibody is reassuring, while a positive antigen means infection and needs clinical follow-up. CDC's serologic patterns make the pairing clear: HBsAg negative with anti-HBs positive and core antibody negative is immunity from vaccination. A positive HBsAg generally indicates current infection and needs clinical interpretation rather than a conclusion drawn at home — and there is one exception directly relevant to this page, since CDC notes HBsAg can be transiently positive within thirty days after a dose of hepatitis B vaccine. If your report lists both markers, read which word it actually says, and take a positive antigen to your clinician.

Hepatitis B Surface Antibody (Anti-HBs), Quantitative: Proving Immunity and What the 10 mIU/mL Threshold Means

Serum

Other names: Hepatitis B Surface Ab Immunity Qn, Hepatitis B Surface Ab Immunity QN, Hepatitis B Surface Ab Immunity, Hepatitis B Surf Ab Immunity QN, Hep B Surface Ab Immunity, Hep B Surf Ab Immunity

Optimal Result: 10 - 100 mIU/ml.

Immune System

From Healthmatters.io Team and reviewed by HealthMatters Editorial Team

Written on September 30, 2026 | Last updated Updated on Sept. 30, 2026

Lab Results Explained and Tracked

At a Glance

This test measures how much hepatitis B surface antibody — anti-HBs — is in your blood, as a number in mIU/mL. Your immune system makes it after a hepatitis B vaccine series or after recovering from infection, so it marks immunity rather than infection.

The number that matters is 10. CDC treats anti-HBs at 10 mIU/mL or above, one to two months after finishing a series, as the marker of vaccine-induced protection. Below that, protection is not documented by this test — a different statement from being unprotected.

What "Qn" means on your report

Qn is not part of the test's name. It is the scale: quantitative, meaning a number rather than a word. The LOINC concept for this observation carries the scale value Qn with example units of mIU/mL.

The same antibody is also run qualitatively, classified as Reactive or Non-Reactive. A quantitative result supplies the concentration, which allows a direct comparison against a threshold. A qualitative classification has a cutoff behind it too, and some reports carry both — the University of Iowa reports reactivity, immune status and a quantitative concentration together — so Reactive alone does not establish that no number exists. Read the whole report.

The 10 mIU/mL threshold, and the grey zone just underneath it

CDC's guidance for health-care personnel states that immunocompetent adults and children with vaccine-induced anti-HBs of 10 mIU/mL or above are seroprotected, and its 2023 screening recommendations use the same figure, measured one to two months after a series.

Laboratories do not all draw the line identically, which is where results near 10 get confusing. Labcorp reports immunity above 10.0 mIU/mL. The University of Washington states that per the manufacturer's insert the protective level is 12 or above. The University of Iowa reports the same antibody by electrochemiluminescence immunoassay in three tiers: non-reactive below 8.5, indeterminate from 8.5 up to 11.5, reactive at 11.5 or above.

So a result of 9, or 11, can be called non-reactive, indeterminate or reactive depending on the laboratory. Within a few units of 10, the reference information on your own report decides.

How to read your result

Read the number against your own report's reference interval, then against your question.

At or above 10 mIU/mL, with a documented complete series and no immune globulin in the last six months, documents protection; for a healthy adult that is the end of the question. Well above 100 is the same answer more emphatically: no guidance behind this page states an upper threshold, so a figure in the hundreds or above a thousand is a strong response, and a high flag comes from the stored bound rather than a clinical ceiling.

Just under 10 is the ambiguous zone above — indeterminate or non-reactive by assay.

Clearly below 10 means protection is not documented by this test. The reasons — never vaccinated, an incomplete series, measurement too soon, antibody declined over years, or a genuine failure to respond — differ in what follows, and the section below separates them.

Any result leaves one question open: this test does not tell you whether you have hepatitis B. Only the full panel does.

One framing note: CDC's Pink Book states routine serologic testing of vaccinated people is not recommended, directing post-vaccination testing at named groups — health-care personnel, hemodialysis patients, immunocompromised people, infants of surface-antigen-positive mothers — but what happens within them differs. For health-care personnel it is documenting a response once. For hemodialysis patients the need for boosters "should be assessed by annual testing", with "a booster dose ... when antibody levels decline below 10 mIU/mL". Immunocompromised people "might need annual testing". What follows about a declining number needing no action applies to immunocompetent documented responders.

If your result is below 10

What happens next is a clinical decision with more than one acceptable route. Where a response was never documented, ACIP describes two options — a second complete series followed by anti-HBs testing, or a single additional dose followed by testing one to two months later. Route and schedule depend on the product: a series is two doses at 0 and 1 month for one vaccine and three at 0, 1 and 6 for others, and the two-dose product may be used even after a non-response to another's.

Non-response is defined as anti-HBs below 10 mIU/mL after two complete series, not after a dose count — and current infection has to be excluded before settling on it. One low result after one series is nowhere near that point.

If you were never vaccinated or did not finish, ACIP has recommended vaccination for adults 19 to 59 since 2022, and for those 60 and over with risk factors.

A number below 10 in someone who previously documented a response — an anti-HBs at or above 10 after a completed series — is a different situation, and the reason is immune memory. For immunocompetent people CDC's Pink Book states immune memory remains intact for more than thirty years and that those whose antibody has declined remain protected against significant infection. Protection is not an open question across the timescales studied; the endpoint is.

The distinction that matters is between completing a series and documenting a response to it: without a post-series result at or above 10 on record, a low number cannot be read as waning.

Proving immunity for work, school or travel

This is why a quantitative anti-HBs is often ordered: it supplies a concentration that can be compared against whatever threshold is asked for. A qualitative result carries a cutoff too and some reports give both, so the practical question is what the requesting institution specifies.

What makes the documentation hold up is the pairing: the result, and the vaccination history it is read against. A figure at or above 10 with a documented series is consistent with vaccine-induced protection; the same figure with no vaccination record is equally consistent with past infection, and only core antibody separates them.

One more thing can supply it. Hepatitis B immune globulin transfers anti-HBs passively rather than provoking it, and CDC states it "can provide anti-HBs for 4-6 months after administration; therefore, testing for anti-HBs ≤6 months after HBIG administration is not an accurate measure of a person's immune status." A protective-looking figure within six months of immune globulin — after an exposure, or at birth to a surface-antigen-positive mother — does not document a vaccine response, whatever the vaccination record says. At the other end, measuring sooner than one to two months after the last dose can understate it.

If you remember only one thing

Ten is a floor, not a target, and this number answers one question. At or above 10 after a complete series documents protection, unless immune globulin in the last six months supplied the antibody. Below 10 means protection is not documented — not that you are unprotected, and not that you have hepatitis B, which is a different test on the same panel.

Two people, same result

Two people both get 4 mIU/mL.

The first is 24, finished a three-dose series six weeks ago for a nursing placement, with no other history. Her result is a first post-vaccination measurement below the threshold, so she is at the start of a defined protocol — one route is a single further dose and a retest in one to two months — not at the end of one.

The second is 58, vaccinated in his thirties, with a record showing both the completed series and an anti-HBs of 140 mIU/mL measured two months afterwards. His 4 mIU/mL today is a declined level in a responder whose response was documented at the time, and for an immunocompetent person CDC's Pink Book puts immune memory at more than thirty years.

Change one detail and the second becomes the first: had his record shown the doses but no post-series result, his 4 would be an undocumented response, not a waned one. The number is identical in all three; what separates them is not in the result.

What this result cannot tell you

Whether you have hepatitis B. Anti-HBs is the immunity marker; the infection markers are HBsAg and core antibody, and CDC's 2023 recommendations put all adults aged 18 and over on once-in-a-lifetime screening with all three together. This test is one leg of that panel.

Whether antibody came from a vaccine, a past infection, or immune globulin. Total anti-HBc separates vaccination from resolved infection; recent HBIG is a question of timing.

Whether you are protected, as against whether protection is documented. A figure below 10 in a documented responder is not evidence of susceptibility.

And it is not absolute even when high: Labcorp states on its own assay that the presence of anti-HBs is not an absolute indicator of resolved hepatitis infection nor of protection from future infection.

Common interpretation mistakes

Reading a high number as too much antibody. There is no upper threshold in the guidance; a high flag comes from a stored bound.

Treating a figure a unit or two below 10 as settled. Assays differ — one reports an indeterminate band from 8.5 to 11.5.

Concluding non-response from one low result. The definition requires anti-HBs below 10 after two complete series, with infection excluded.

Reading this test as a hepatitis B screen. It cannot detect infection, and a normal result here says nothing about HBsAg.

Taking the antibody as proof of vaccination without the record. Past infection produces anti-HBs too, and core antibody is what separates them.

Reading a low number as waning without a documented prior response. Without a post-series result at or above 10 on record, there is nothing established to have waned from.

Measuring too soon. CDC's window is one to two months after the last dose.

Questions your doctor may ask

Have you had a hepatitis B vaccine series, how many doses, and do you have the dates? Was your antibody ever checked after that series, and what was the result? Have you had hepatitis B immune globulin in the last six months, after an exposure or at birth? Are you on dialysis, immunosuppressed, or living with HIV? Are you being asked for proof of immunity, and does the requester specify a threshold? Have you ever been told you had hepatitis B? Were you born in, or have you lived in, a country where hepatitis B is common?

Read together with

The other two legs answer what this one cannot. HBsAg marks current infection. Total anti-HBc indicates past or present infection and separates vaccine-induced antibody from antibody left by a resolved one; IgM core antibody then distinguishes a recent infection from an older one. CDC's 2023 recommendation is to run all three together. If this antibody was also run qualitatively, that is the same antibody classified as Reactive or Non-Reactive.

Clinical pearls

The threshold belongs to the assay, not the antibody. Ten, twelve, and an indeterminate band from 8.5 to 11.5 are all in use, and a result near the line is interpreted by the report it arrived on.

Measurable antibody and protection are not the same quantity, and one can decline while the other persists — in immunocompetent people CDC puts immune memory at more than thirty years. What is under study is the endpoint, not whether decades of protection exist.

Clinical Takeaway

Anti-HBs indicates immunity to hepatitis B, not infection with it. CDC treats 10 mIU/mL or above, one to two months after a completed series, as documenting vaccine-induced protection and states no upper limit, so a high figure is a strong response and a high flag reflects a stored bound. Results within a unit or two of 10 depend on the assay, one reporting an indeterminate band from 8.5 to 11.5. Where no response was ever documented, a result below 10 leads to clinician-managed revaccination — a further series or a single dose — then retesting; non-response is defined only after two complete series with infection excluded. A declined level in a documented responder is separate: for an immunocompetent person CDC puts immune memory at more than thirty years, while dialysis responders have a recommended annual test with a booster below 10 and immunocompromised people "might need annual testing". Recent immune globulin can supply the antibody, making a result within six months uninterpretable. And whatever the number, this test cannot tell you whether you have hepatitis B.

In one sentence

This number says whether protection is documented, not whether you are infected, and 10 mIU/mL is a floor rather than a target.

Bottom line

At or above 10 with a record of a complete series, you have what a proof-of-immunity request asks for — unless you had immune globulin within the last six months, which supplies the antibody itself and makes the result uninterpretable. Below 10, bring your vaccination dates and any previous antibody result to your clinician; what follows depends on those more than on the number.

FAQ about Hepatitis B Surface Ab Immunity, Qn

What does "Qn" mean on a hepatitis B surface antibody result?

Qn is the scale, not part of the test's name. It means quantitative: the result comes back as a number in mIU/mL rather than as a word. That is how the standard laboratory vocabulary labels it too — the LOINC concept for this observation, Hepatitis B virus surface Ab [Units/volume] in Serum or Plasma by Immunoassay, carries the scale value Qn with example units of mIU/mL. The distinction matters because the same antibody is also run qualitatively, classified as Reactive or Non-Reactive. A quantitative result supplies the concentration, which is what allows a direct comparison against a threshold such as 10 mIU/mL. A qualitative classification has a cutoff behind it too, and some reports carry both — the University of Iowa reports reactivity, immune status and a quantitative concentration together — so seeing Reactive does not establish that no number exists. Read the whole report, and if you are being asked for documented proof of immunity, check what the requesting institution accepts.
What is the normal range for hepatitis B surface antibody?

It is better thought of as a threshold than a range, because the guidance states a floor with nothing above it. CDC treats anti-HBs at 10 mIU/mL or above, measured one to two months after a completed vaccine series, as documenting vaccine-induced protection. Labcorp reports its reference interval as immunity above 10.0 mIU/mL. There is no upper limit in any of these sources, so a result in the hundreds or above a thousand is a strong response rather than an abnormality. Laboratories do differ near the line: the University of Washington cites a protective level of 12 mIU/mL or above per the manufacturer's package insert, and the University of Iowa reports three tiers — non-reactive below 8.5, indeterminate from 8.5 to 11.5, and reactive at 11.5 or above. The reference information printed on your own report is what applies to your number.
My hepatitis B surface antibody is low — what does that mean?

It means protection is not documented by this test, which is narrower than being unprotected. What follows depends on your vaccination record, and the decision belongs with your clinician. If you recently finished a series, the measuring window is one to two months after the last dose, and a result below 10 there has two acceptable routes in ACIP's recommendations: a second complete series followed by testing, or a single additional dose followed by testing one to two months later — route and schedule by product. Non-response is defined only after two complete series with infection excluded, not by a dose count. Never vaccinated or an incomplete series points to starting or completing one. And if your records show a previous anti-HBs at or above 10 after a completed series, a low number now is a declined level in a documented responder. For an immunocompetent person, CDC's Pink Book states immune memory remains intact for more than thirty years and that such recipients remain protected. Two groups differ even so: dialysis patients, for whom annual testing is advised with a booster below 10, and immunocompromised people, who "might need annual testing".
What does a result of less than 5 mIU/mL mean?

A result written as <5 reports a concentration below 5 mIU/mL. It is the laboratory's reporting convention rather than a precise figure, and what it means analytically — whether 5 is a detection limit, a quantification limit, or simply the lowest value that laboratory prints — is established by that laboratory's own assay documentation, not by the number itself. Clinically it sits where any result below the threshold sits: protection is not documented by this test. It is worth separating from a figure just under 10, which is genuinely borderline and assay-dependent — the University of Iowa reports an indeterminate band from 8.5 up to 11.5 mIU/mL, and <5 is well below that zone. What follows depends on your vaccination record: never vaccinated or an incomplete series points to starting or completing one, while a documented prior response at or above 10 puts a low number now in the waning category instead.
Is a high hepatitis B surface antibody level bad?

No. There is no upper threshold for this antibody in any current guidance — CDC states 10 mIU/mL or above as a floor and names no ceiling, and Labcorp's reference interval is simply immunity above 10.0 mIU/mL. A result in the hundreds or above a thousand is a strong antibody response, which is the outcome a vaccine series is meant to produce. One published laboratory scheme grades anti-HBs above 100 mIU/mL as a good response and gives the same management advice whether the figure is 101 or 10,000. If your result is flagged high, that flag comes from the upper bound stored for the marker rather than from anything clinical. Two caveats remain regardless of how high the number is: it does not distinguish vaccine-induced antibody from antibody left by a resolved infection, and Labcorp notes on its own assay that the presence of anti-HBs is not an absolute indicator of resolved infection nor of protection from future infection.
Does this test show whether I have hepatitis B?

No, and this is the one thing on the page worth being certain about. Anti-HBs is the immunity marker. The infection markers are HBsAg, the surface antigen, which indicates current infection, and total anti-HBc, the core antibody, which indicates past or present infection. A person can have a reassuring anti-HBs result and an active hepatitis B infection is not ruled out by it, because the two questions are answered by different tests. CDC's 2023 recommendations put all adults aged 18 and over on once-in-a-lifetime screening using all three together — HBsAg, anti-HBs and total anti-HBc — precisely because no one of them answers the whole question. If you are worried about an exposure or about infection rather than about documenting immunity, the antigen and core antibody tests are the ones to ask about.
How can I tell whether my antibody came from the vaccine or from a past infection?

Not from this number, which is identical either way. The test that separates them is total anti-HBc, the core antibody, because hepatitis B vaccines do not produce it — only infection does. Positive anti-HBs with negative total anti-HBc is the pattern of vaccine-induced immunity. Positive anti-HBs with positive total anti-HBc, and HBsAg negative, is the pattern of an infection that resolved. Both leave you with antibody, and both are reported as a number in mIU/mL on this test. The distinction matters for more than curiosity: a proof-of-immunity request is asking about the vaccine pattern, and a resolved infection carries its own follow-up considerations. In practice, your documented vaccination history plus the core antibody result is what settles it.
Do I need a booster if my level has dropped below 10?

For an immunocompetent adult who has documented a response — an anti-HBs at or above 10 recorded after a completed series — generally not. CDC notes anti-HBs concentrations might wane among responders, and its Pink Book states that in immunocompetent recipients immune memory remains intact for more than thirty years following immunization and that those whose antibody has declined remain protected against significant infection. So the protection is not in doubt across the timescales studied; the open question is the ultimate endpoint rather than whether decades of protection exist. CDC also states that routine serologic testing to assess immune status in vaccinated people is not recommended, which is why a declining number in a documented responder does not usually generate any action. The picture differs if a response was never documented in the first place, or if you are immunosuppressed, on dialysis, or in an occupational program with its own schedule — those follow specific protocols rather than this general answer.
I need to prove hepatitis B immunity for work or school — is this the right test?

Yes, and the quantitative version is often the one asked for, because it supplies a concentration that can be compared directly against a stated threshold. A qualitative classification carries a cutoff of its own and some reports give both a word and a number, so the question is what the requesting institution accepts, worth checking before chasing a repeat test. One caveat: immune globulin supplies anti-HBs passively, and CDC states testing within six months of it "is not an accurate measure of a person's immune status". What makes the documentation hold up is the pairing: the result together with the vaccination history it is read against. Anti-HBs at 10 mIU/mL or above alongside a documented complete series documents vaccine-induced protection. The same figure with no vaccination record is equally consistent with a past infection, which this number cannot distinguish. Timing matters too — CDC's window is one to two months after the last dose of the series, and measuring sooner can understate the response. If the body asking for proof specifies its own threshold, that figure rather than a general one is what you need to meet, so it is worth checking what they have asked for.
What is the difference between this test and hepatitis B surface antigen?

One letter, and opposite meanings. Surface antibody — anti-HBs, this test — is made by your immune system and indicates immunity, from a vaccine or from a resolved infection. Surface antigen — HBsAg — is part of the virus itself, and its presence indicates current hepatitis B infection, acute or chronic. They are easy to confuse on a report because the names differ by so little, and the consequence of confusing them is large: a positive antibody is reassuring, while a positive antigen means infection and needs clinical follow-up. CDC's serologic patterns make the pairing clear: HBsAg negative with anti-HBs positive and core antibody negative is immunity from vaccination. A positive HBsAg generally indicates current infection and needs clinical interpretation rather than a conclusion drawn at home — and there is one exception directly relevant to this page, since CDC notes HBsAg can be transiently positive within thirty days after a dose of hepatitis B vaccine. If your report lists both markers, read which word it actually says, and take a positive antigen to your clinician.

Lab Results Explained and Tracked

All Your Lab Results.
One Simple Dashboard.

Related Health Conditions

All Your Lab Results.
One Simple Dashboard.

Import, Track, and Share Your Lab Results Easily

Import, Track, and Share Your Lab Results

Import lab results from multiple providers, track changes over time, customize your reference ranges, and get clear explanations for each result. Everything is stored securely, exportable in one organized file, and shareable with your doctor—or anyone you choose.

Cancel or upgrade anytime

What does it mean if your Hepatitis B Surface Ab Immunity, Qn result is too low?

A result below 10 mIU/mL means protection is not documented by this test. That is a narrower statement than being unprotected, and what follows from it depends on your vaccination history more than on the number.

First, how close to 10. Laboratories do not draw the line identically — the University of Iowa reports this antibody by electrochemiluminescence immunoassay as non-reactive below 8.5, indeterminate from 8.5 up to 11.5, and reactive at 11.5 or above, while the University of Washington cites a protective level of 12 or above per the manufacturer's insert. A figure within a unit or two of 10 is interpreted by the reference information on your own report.

If you were never vaccinated or did not complete a series, the current schedules are two doses at 0 and 1 month or three doses at 0, 1 and 6 months, depending on the product.

If you have recently completed a series, the measurement window is one to two months after the last dose. A result below 10 there is a clinical decision, and ACIP describes two acceptable routes: a second complete series followed by anti-HBs testing, or a single additional dose followed by testing one to two months later. The schedule depends on the product — two doses at 0 and 1 month for one vaccine, three at 0, 1 and 6 months for others. Non-response is anti-HBs below 10 after two complete series with current infection excluded, not a dose count. Measuring too soon after a dose can also understate the response.

Separately: hepatitis B immune globulin supplies anti-HBs passively, and CDC states testing within six months of it is not an accurate measure of immune status — relevant if you had it after an exposure or at birth.

If your records show a previous anti-HBs at or above 10 after a completed series, this is a declined level in a documented responder rather than a failure. For an immunocompetent person, CDC's Pink Book states immune memory remains intact for more than thirty years and that such recipients remain protected despite the fall, and that routine serologic testing of vaccinated people is not recommended. Two groups are managed differently even after documenting a response: hemodialysis patients, for whom annual testing is advised with a booster below 10 mIU/mL, and immunocompromised people, who "might need annual testing". Without a prior result at or above 10, there is nothing established to have declined from.

A low result does not mean you have hepatitis B. If infection is the question, HBsAg and total anti-HBc are the tests that answer it.

Related Biomarkers

Article Review & Sources

All our content is backed by peer-reviewed studies, academic research, and trusted medical sources. We're committed to accuracy and transparency — see our editorial policy for details.

Laboratories

Bring All Your Lab Results Together — In One Place

We accept reports from any lab, so you can easily collect and organize all your health information in one secure spot.

Pricing Table

Gather Your Lab History — and Finally Make Sense of It

Finally, Your Lab Results Organized and Clear

Choose the plan that fits you — and turn scattered lab reports into clear insights you can finally use.

Pick a plan that fits you — and turn scattered lab reports into clarity.

Personal plans

Professional plan

$79/ year

Advanced Plan

Access your lab reports, explanations, and tracking tools.

Import lab results from any provider
Track all results with visual tools
Customize your reference ranges
Export your full lab history anytime
Share results securely with anyone
Receive 5 reports entered for you
Cancel or upgrade anytime

$250/ once

Unlimited Account

Pay once, access everything—no monthly fees, no limits.

Import lab results from any provider
Track all results with visual tools
Customize your reference ranges
Export your full lab history anytime
Share results securely with anyone
Receive 10 reports entered for you
No subscriptions. No extra fees.

Professional plan

$45/ month

Pro Monthly

Designed for professionals managing their clients' lab reports

Import lab results from any provider
Track lab results for multiple clients
Customize reference ranges per client
Export lab histories and reports
Share results and reports with clients
Invite clients to their accounts
Begin with first report entered by us
Cancel or upgrade anytime

About membership

What's included in a Healthmatters membership

Import Lab Results from Any Source

Easily upload lab results from any provider, whether it's a hospital, independent lab, or home testing service. We support PDFs, scanned documents, and JPEGs from patient portals. No need to log in to multiple platforms — everything is centralized in one secure space.

Easily upload lab results from any provider — we support PDFs, scans, and images. Keep all your reports organized in one secure place.

See Your Health Timeline

Every lab result is automatically organized on a chronological timeline, giving you a complete picture of your health journey. Whether you're tracking a condition, managing treatments, or staying proactive, the timeline helps you and your doctor understand how things progress over time.

Every lab result is automatically organized on a chronological timeline, giving you a complete picture of your health journey.

Understand What Your Results Mean

Whether it's a blood test, GI panel, urinalysis, or something else, lab reports measure numerous biomarkers that reveal what's happening inside your body. Our extensive database covers over 10,000 biomarkers, providing clear, simple explanations of what each result means and how you can take action—no matter your membership level. Say goodbye to confusion and get the insights you need to better understand your health.

Our database covers over 10,000 biomarkers with clear, simple explanations—so you can finally understand your results and what to do next.

Enter Your Lab Reports Yourself — Always Free Enter Your Lab Reports — Always Free

If you'd like to handle inputting your health data into your account, you can do so with our easy-to-use data entry forms. Our user-friendly form is designed to guide you through the quick and easy submission process, making it simple to keep track of your health metrics. This is available to both Advanced plan and Unlimited plan members.

Our user-friendly form guides you through a quick, simple submission process, making it easy to enter your health metrics.

Add your results anytime with our easy entry form. It's quick, guided, and helps you stay organized — free for all members.

Visualize Your Results

View your lab data through easy-to-read graphs and tables. Quickly spot patterns, track changes, and compare results across different dates — all without digging through multiple reports. You can also select and compare graphs of specific biomarkers side-by-side to better understand how they relate and change over time.

See your lab reports in clear graphs and tables. Spot patterns, track changes, and compare results over time — all in one place.

Export Your Complete Lab History in a Single File Export Your Complete Lab History

After collecting lab results from different providers, you can download your entire history combined into a single file. Choose from PDF, Excel, or CSV formats to easily review, share, or get a second opinion—no more juggling multiple reports.

After collecting lab results from different providers, you can download your entire history combined into a single file.

Comprehensive Data Entry Service for Your Reports Data Entry Service for Your Reports

Our inclusive service handles the data entry for your lab reports. Just submit your information and we'll take care of the rest. Advanced plan members receive five reports entered for free, then $15 per report after that. Unlimited plan members receive ten report entries for free, then $15 per report after that.

Our inclusive service handles the data entry for your lab reports. Just submit your information and we'll take care of the rest.

Securely Share With Anyone You Trust

Whether you're working with a doctor, nutritionist, caregiver, or wellness coach, you can securely share your complete lab history by sending an invite link to anyone you trust. You have full control over who sees your information and for how long, ensuring your privacy and peace of mind at every step.

Share your full lab history with your doctor, nutritionist, or coach using a secure invite link.

Discover

Let Your Lab Results Tell the Full Story

Once your results are in one place, see the bigger picture — track trends over time, compare data side by side, export your full history, and share securely with anyone you trust.

Bring all your results together to compare, track progress, export your history, and share securely.

I have been using Healthmatters.io since 2021. I travel all over the world and use different doctors and health facilities. This site has allowed me to consolidate all my various test results over 14 years in one place. And every doctor that I show this to has been impressed. Because with any health professional I talk to, I can pull up historical results in seconds. It is invaluable. Even going back to the same doctor, they usually do not have the historical results from their facility in a graph format. That has been very helpful.

Anthony

Unlimited Plan Member since 2021

What fantastic service and great, easy-to-follow layouts! I love your website; it makes it so helpful to see patterns in my health data. It's truly a pleasure to use. I only wish the NHS was as organized and quick as Healthmatters.io. You've set a new standard for health tracking!

Karin

Advanced Plan Member since 2020

As a PRO member and medical practitioner, Healthmatters.io has been an invaluable tool for tracking my clients' data. The layout is intuitive, making it easy to monitor trends and spot patterns over time. The ability to customize reports and charts helps me present information clearly to my clients, improving communication and outcomes. It's streamlined my workflow, saving me time and providing insights at a glance. Highly recommended for any practitioner looking for a comprehensive and user-friendly solution to track patient labs!

Paul

Healthmatters Pro Member since 2024

We implement proven measures to keep your data safe.

At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.

Hepatitis B Surface Antibody (Anti-HBs), Quantitative: Proving Immunity and What the 10 mIU/mL Threshold Means

At a Glance

What "Qn" means on your report

The 10 mIU/mL threshold, and the grey zone just underneath it

How to read your result

If your result is below 10

Proving immunity for work, school or travel

If you remember only one thing

Two people, same result

What this result cannot tell you

Common interpretation mistakes

Questions your doctor may ask

Read together with

Clinical pearls

Clinical Takeaway

In one sentence

Bottom line

FAQ about Hepatitis B Surface Ab Immunity, Qn

What does "Qn" mean on a hepatitis B surface antibody result?

What is the normal range for hepatitis B surface antibody?

My hepatitis B surface antibody is low — what does that mean?

What does a result of less than 5 mIU/mL mean?

Is a high hepatitis B surface antibody level bad?

Does this test show whether I have hepatitis B?

How can I tell whether my antibody came from the vaccine or from a past infection?

Do I need a booster if my level has dropped below 10?

I need to prove hepatitis B immunity for work or school — is this the right test?

What is the difference between this test and hepatitis B surface antigen?

All Your Lab Results. One Simple Dashboard.

Related Health Conditions

All Your Lab Results. One Simple Dashboard.

Import, Track, and Share Your Lab Results Easily

Import, Track, and Share Your Lab Results

What does it mean if your Hepatitis B Surface Ab Immunity, Qn result is too low?

Related Biomarkers

Article Review & Sources

Bring All Your Lab Results Together — In One Place

Gather Your Lab History — and Finally Make Sense of It

Finally, Your Lab Results Organized and Clear

Advanced Plan

Unlimited Account

Pro Monthly

What's included in a Healthmatters membership

Import Lab Results from Any Source

See Your Health Timeline

Understand What Your Results Mean

Enter Your Lab Reports Yourself — Always Free Enter Your Lab Reports — Always Free

Visualize Your Results

Export Your Complete Lab History in a Single File Export Your Complete Lab History

Comprehensive Data Entry Service for Your Reports Data Entry Service for Your Reports

Securely Share With Anyone You Trust

Let Your Lab Results Tell the Full Story

Once your results are in one place, see the bigger picture — track trends over time, compare data side by side, export your full history, and share securely with anyone you trust.

Bring all your results together to compare, track progress, export your history, and share securely.

What Healthmatters Members Are Saying

Use promo code to save 10% off any plan.

We implement proven measures to keep your data safe.

All Your Lab Results.
One Simple Dashboard.

All Your Lab Results.
One Simple Dashboard.