On your lab requisition: Quest “HIV-1/2 Antigen and Antibodies, Fourth Generation, with Reflexes” (test code 91431)Labcorp “HIV Ab/p24 Ag with Reflex” (test no. 083935)BioReference “HIV AG/AB 4th Generation” (test code B688-3)
The short answer
HIV 1/2 Antigen & Antibodies (4th Gen) measures HIV-1/2 Antibodies and HIV p24 Antigen from a standard blood draw. At TestWell it costs $39.99 plus a $6 lab processing fee, needs no fasting, and results post in 1–4 business days. Physician-authorized with no doctor's visit or insurance needed; draw at Labcorp.
Hospital Lab
$150
cash pay
Other Labs
$55
+ lab fees
TestWell
$39.99
+ $6 lab processing fee
The fourth-generation HIV test detects both HIV-1/HIV-2 antibodies and the p24 antigen, allowing for earlier detection than antibody-only tests. It can detect HIV as early as 2–4 weeks after exposure (compared to 3–12 weeks for older tests). This is the CDC-recommended screening method for all adults aged 15–65. The test includes reflexes to confirmatory testing if the screen is positive.
4th-generation HIV test detects both HIV antibodies and the p24 antigen — catches infection as early as 2-4 weeks post-exposure. Recommended annual screening per CDC for at-risk adults; one-time screening for all adults 18-65.
Any sexually active adult per CDC routine-screening guidance, anyone with new partners, post-exposure screening (3 weeks after exposure for 4th-gen testing), routine MSM testing every 3-6 months, anyone with symptoms of acute HIV (flu-like illness 2-4 weeks after exposure).
Sample Type
Blood draw
Fasting
Not required
Results In
1–4 business days
Performed At
Labcorp
2 biomarkers tested
Your HIV 1/2 Antigen & Antibodies (4th Gen) results will include values for each of the 2 biomarkers tested, along with reference ranges. Results are reviewed by a licensed physician before being released to your secure portal.
If any values fall outside the normal range, your report will include guidance on what that may mean and recommended next steps. You'll receive an email notification when your results are ready, typically within 1–4 business days.
Typical reference range layout
Lab reports show where your value sits relative to established reference intervals—your physician interprets this in context for you. Already have results? Analyze them with your AI assistant against our physician-reviewed ranges.
No fasting required. No special preparation needed. Window period: 2–4 weeks after exposure.
An HIV 1/2 Antigen & Antibodies (4th Gen) test costs $39.99 at TestWell — $45.99 all-in when ordered alone, because the $6 lab processing fee is charged once per order, with no draw fee or physician fee added. Ordered directly from the labs' own consumer sites, the closest equivalent lists at $85.00 at Quest Health and $99.00 at Labcorp OnDemand (list prices checked Sep 12, 2026; see the notes on how the products differ). Hospital outpatient labs typically bill around $150.00 self-pay for the same test, and often more. With insurance, what you pay depends on your deductible and your plan's negotiated rate; TestWell's price is fixed before the draw and is HSA/FSA-eligible.
| Where you order | Price | One test, all-in | Notes |
|---|---|---|---|
| TestWell (drawn at Labcorp) | $39.99 | $45.99 | Includes the one $6 lab processing fee, charged once per order |
| TestWell (drawn at BioReference — New York & New Jersey) | $33.99 | $39.99 | New York and New Jersey orders route to BioReference; Quest Health and Labcorp OnDemand don't take self-ordered draws in those states |
| Quest Health (Quest Diagnostics' own site) | $85.00 | $85.00 | Both are 4th-generation antigen/antibody screens with confirmation · list price checked Sep 12, 2026 |
| Labcorp OnDemand (Labcorp's own site) | $99.00 | $99.00 | list price checked Sep 12, 2026 |
| Hospital outpatient lab, self-pay (typical) | $150.00 | $150.00 | Reference figure; hospital charges vary widely by facility and are often higher |
46% less than the lower lab-direct list price, for the same draw at the same lab. Lab test codes: Quest test code 91431 · Labcorp test no. 083935 · BioReference code B688-3. Competitor prices are read from the linked public pages and re-checked regularly; the labs' sites may add taxes or change prices without notice.
Compare more: Quest Diagnostics price list · Labcorp price list · Quest vs Labcorp · Lab test price checker
Both HIV antibodies (your immune response, takes 4-12 weeks to develop) and the p24 antigen (a viral protein detectable 2-4 weeks after infection). 4th-gen testing closes the 'window period' significantly vs older antibody-only tests — catches most acute infections at 2-4 weeks vs 3 months.
4th-gen testing detects most infections by 2-4 weeks post-exposure. CDC recommends initial test at 2-4 weeks, repeat at 6 weeks and 3 months for a definitive result. PEP (post-exposure prophylaxis) is most effective within 72 hours — go to urgent care immediately if recent exposure.
All TestWell HIV tests use a confirmatory algorithm — a reactive screen automatically triggers a confirmatory Western blot or HIV-1/2 differentiation test before reporting positive. Effective treatment makes HIV a manageable chronic condition with near-normal life expectancy. We'll connect you with care providers and resources.
On TestWell, the HIV 4th-Gen test is $39.99. Quest Direct lists the same test at $55, walk-in hospital labs typically bill $100-150 without insurance. Free testing is also available at most community health centers and Planned Parenthood — check your state's options.
The CPT code for 4th-generation HIV-1/2 antigen/antibody screen is 87389. Confirmatory testing uses additional codes (87534 for HIV-1 RNA, 86703 for confirmation).
Yes if you haven't been tested recently or have a new partner. The STI Comprehensive Panel bundles HIV with chlamydia & gonorrhea, syphilis, hepatitis B, and hepatitis C at a discount.
Not always — many public health departments and community clinics offer free or low-cost HIV testing, and insurance plans cover routine screening. If you want it private, fast and on your own schedule, TestWell's 4th-generation HIV-1/2 antigen/antibody test is $39.99 with no doctor's visit or insurance, drawn at Labcorp with results in 1–4 business days; a positive screen reflexes to confirmatory testing automatically.
Ordered directly, the closest equivalent lists at $85.00 at Quest Health (Quest Diagnostics' own site) and $99.00 at Labcorp OnDemand (prices checked September 2026). TestWell orders the same test at the same Labcorp patient service centers for $39.99 — $45.99 all-in with the $6 per-order lab processing fee — paid out of pocket at checkout with no insurance, doctor's visit or draw fee; HSA and FSA cards are accepted.
No, fasting is not required for an HIV 1/2 Antigen & Antibodies (4th Gen) test — you can eat normally and book any time of day. Window period: 2–4 weeks after exposure.
Order the HIV 1/2 Antigen & Antibodies (4th Gen) test online from TestWell for $39.99 (plus a $6 per-order lab processing fee) — no doctor's visit, referral or insurance needed. A licensed physician authorizes the order, then you walk into any Labcorp patient service center near you for the draw (the lab locator on our site lists the closest ones by ZIP code), and results arrive in 1–4 business days.
The HIV 1/2 Antigen & Antibodies (4th Gen) test is Quest Diagnostics test code 91431 ("HIV-1/2 Antigen and Antibodies, Fourth Generation, with Reflexes"), Labcorp test number 083935 ("HIV Ab/p24 Ag with Reflex"), BioReference code B688-3 ("HIV AG/AB 4th Generation") (CPT 87389). TestWell orders it under those codes for $39.99 at Quest, Labcorp or BioReference — no doctor's visit or insurance required, results in 1–4 business days. Codes verified against the labs' catalogs in 2026.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
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TestWell Price
$39.99
+ $6 lab processing fee at checkout
No insurance needed · HIPAA compliant
Better value: the STI Basic Panel
Save $7.99This test is part of the STI Basic Panel — 2 tests · 4 biomarkers for $84.99, $7.99 less than à la carte.
$84.99$92.98
2 tests · 4 biomarkers
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HIV 1/2 Antigen & Antibodies (4th Gen)
$39.99