CA 125 Test Cost and Medicare Coverage (CPT 86304)

Also called: cancer antigen 125 · CA-125 blood test · CA 125 level · cancer antigen 15-3 · cancer antigen 27.29 — all the same test, CPT 86304 (related code: 86300).

The short answer

Covered as a baseline before surgery for a suspicious pelvic mass, and for monitoring ovarian cancer and its relatives on a set schedule. Not covered to work out what a pelvic mass is, and not covered to evaluate symptoms. Medicare’s national policy (NCD 190.28, the same in every state) covers CA 125 “as part of the initial pre-operative work-up for women presenting with a suspicious pelvic mass to be used as a baseline for purposes of post-operative monitoring,” and then for tracking ovarian cancer through and after treatment: three levels in the first month after treatment, a level at the end of chemotherapy, surveillance “every 3 months for 2 years, every 6 months for the next 3 years, and yearly thereafter,” and a level before each treatment cycle for advanced or recurrent disease.

The two sentences that get CA 125 claims denied are in the policy’s limitations. First: “These services are not covered for the evaluation of patients with signs or symptoms suggestive of malignancy.” Second: “The CA 125 is specifically not covered for aiding in the differential diagnosis of patients with a pelvic mass as the sensitivity and specificity of the test is not sufficient.” The distinction is narrow and matters: a level drawn before surgery as a baseline for later comparison is covered; the same test drawn to help decide what the mass is, is not.

This page also covers CA 15-3 and CA 27.29 (CPT 86300), the breast cancer markers governed by the neighboring policy, NCD 190.29, in their own section below.

When Medicare DOES cover CA 125

The national policy’s covered picture, in plain English:

• A pre-operative baseline for a suspicious pelvic mass. The policy covers the level “as part of the initial pre-operative work-up for women presenting with a suspicious pelvic mass to be used as a baseline for purposes of post-operative monitoring.”
• The first month after treatment for ovarian cancer. “Initial declines in CA 125 after initial surgery and/or chemotherapy for ovarian carcinoma are also measured by obtaining three serum levels during the first month post treatment to determine the patient’s CA 125 half-life.”
• At the end of chemotherapy, “as an index of residual disease.”
• Surveillance on a schedule: “every 3 months for 2 years, every 6 months for the next 3 years, and yearly thereafter.”
• Advanced or recurrent disease: “CA 125 levels may be obtained prior to each treatment cycle.”
• Related cancers. The policy says CA 125 “is also elevated in carcinomas of the fallopian tube, endometrium, and endocervix,” and may be associated with “a malignant mesothelioma or primary peritoneal carcinoma.”

The policy notes that CA 125 is “elevated in 80 percent of patients who present with epithelial ovarian carcinoma,” which is another way of saying it is not elevated in the rest. If one of these genuinely describes your situation, the diagnosis for it belongs on your doctor’s order, and coverage follows.

When Medicare does NOT cover CA 125

• Evaluating symptoms. “These services are not covered for the evaluation of patients with signs or symptoms suggestive of malignancy.” A symptom that makes someone wonder about ovarian cancer is, under this policy, not a covered reason to draw CA 125.
• Working out what a pelvic mass is. “The CA 125 is specifically not covered for aiding in the differential diagnosis of patients with a pelvic mass as the sensitivity and specificity of the test is not sufficient.” The covered pre-operative use is a baseline for later comparison, not a diagnostic test of the mass.
• Screening, including screening for high-risk women. MedlinePlus lists screening “if your risk is very high” as one way providers use the test, and adds that “your provider cannot use a CA-125 to screen for ovarian cancer if you aren’t at high risk.” Medicare’s policy is stricter than that: it lists no high-risk screening indication at all and never uses the word screening. Quest’s directory says “CA 125 is not recommended as a cancer screening procedure to detect cancer in the general population,” and Cleveland Clinic says the test “shouldn’t be used if you have no symptoms or risk factors for ovarian cancer.”
• More than one tumor marker for the same cancer. “In general, a single ‘tumor marker’ will suffice in following a patient with one of these malignancies.”

(Never ask anyone to change a code just to get coverage; that is fraud. But doctors often have a legitimate reason for the test that simply wasn’t written down.)

CA 15-3 and CA 27.29 (CPT 86300): the breast cancer markers

The policy next door, NCD 190.29, covers two markers that share one CPT code and one Medicare rate. The policy says “CA 15-3 is often medically necessary to aid in the management of patients with breast cancer,” that “serial testing must be used in conjunction with other clinical methods for monitoring breast cancer,” and that “CA 27.29 is equivalent to CA 15-3 in its usage in management of patients with breast cancer.” MedlinePlus’s tumor marker overview lists both for breast cancer, to “monitor treatment in people with advanced breast cancer.”

Two rules from that policy:

• One or the other, not both. “For monitoring, if necessary, use consistently either CA 15-3 or CA 27.29, not both.” An order that carries both markers is asking Medicare to pay for a test its own policy calls unnecessary.
• The same symptoms exclusion as CA 125. “These services are not covered for the evaluation of patients with signs or symptoms suggestive of malignancy.” The covered use is for someone with a breast cancer diagnosis, “to assess either the presence of recurrent disease or the patient’s response to treatment with subsequent treatment cycles.”

The policy says nothing about anyone without a breast cancer diagnosis, and Quest’s directory carries the same Medicare limited-coverage notice on both CA 15-3 and CA 27.29 as on CA 125.

What you pay if it IS covered: $0

Covered lab tests cost Medicare patients nothing, with no deductible and no 20% coinsurance. Medicare pays the lab $20.81 for a CA 125 test, and the same $20.81 for CA 15-3 or CA 27.29 (CPT 86300). You owe zero.

What you pay if it is NOT covered, read this before you sign

Quest’s own test directory flags CA 125, CA 15-3, and CA 27.29 as “subject to a Medicare Limited Coverage Policy” that “may require a signed ABN when ordering.” (Labcorp’s pages carry no such notice.) If the test is on your order to evaluate symptoms, to help diagnose a pelvic mass, or with no cancer diagnosis behind it, expect the Advance Beneficiary Notice (ABN), the signature pad, committing you to the lab’s own billing rates if Medicare denies the claim. Before you sign:

1. Ask the lab to print exactly what you would owe. You’re entitled to see the number in black and white first. For perspective: when Medicare covers this exact test, it pays the lab $20.81.
2. Ask which markers are on the order. If it lists both CA 15-3 and CA 27.29, ask your doctor whether both are needed; the policy says to use one consistently, not both.
3. Know the direct prices: a CA 125 test sells for about $49.90 all in at Ulta Lab Tests (partner link in the table; our commission is disclosed there) and $58.00 all in at Jason Health (jasonhealth.com, including their flat $18 lab-collection fee per order). Quest’s consumer site, Labcorp OnDemand, and Personalabs do not sell it. Same certified labs, same blood draw. CA 15-3 and CA 27.29 sell for $35 each at Jason Health and $48.95 and $40.95 at Ulta, plus each site’s fee.

Before you sign the pad, 60-second checklist

1. Ask: “Can you print what I’ll owe if Medicare doesn’t pay?”
2. Ask your doctor: “Is this a baseline before surgery or a follow-up of a cancer already on my chart, and is that on the order?”
3. Compare the printed price to the direct-purchase prices before deciding how to proceed.

What counts as a “normal” CA 125 level

Start with the range printed on your own report. Published ranges for CA 125 exist, they differ from lab to lab, and MedlinePlus, notably, publishes no number at all.

• Cleveland Clinic says “generally, levels higher than 35 units per milliliter are considered irregular.”
• Quest’s directory gives a CA 125 range of under 35 U/mL, and a CA 15-3 range of under 32 U/mL; its CA 27.29 range is hidden until a service area is chosen.
• Labcorp’s reference interval for CA 125 is 0.0 to 38.1 units/mL for women, with the interval for men listed as “not established.” For CA 15-3 it is 0.0 to 25.0 units/mL, and for CA 27.29 it is 0 to 38.6 units/mL. Two labs, two different upper limits, for each test.
• MedlinePlus gives no range.

None of the sources we checked gives a treatment target for any of these markers, so there is no “clinical target” to add here. What every source does say is that the number is not a diagnosis. MedlinePlus: “While high CA-125 levels don’t always mean ovarian cancer, a normal CA-125 test result doesn’t rule it out.” Cleveland Clinic: “the test alone doesn’t diagnose or detect cancer.” The National Cancer Institute says “having an elevated level of a tumor marker does not mean that someone has cancer,” that “noncancerous conditions can sometimes cause an increase in the level of a tumor marker,” and that “not everyone with a particular type of cancer will have a higher level of a tumor marker associated with that cancer.”

(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 imaging, your earlier levels, and your history.

Quick questions people ask

What is a CA 125 test? MedlinePlus says “this test measures the amount of a protein called CA-125 (cancer antigen 125) in a sample of your blood.” Medicare’s policy describes tumor markers like it as proteins or carbohydrates whose blood level, “when elevated,” “may reflect tumor size and grade.” The National Cancer Institute lists CA-125 as a marker for ovarian cancer. On billing paperwork it is CPT code 86304.

Can a CA 125 test screen for ovarian cancer? MedlinePlus says providers may use it “to screen for ovarian cancer if your risk is very high,” and that “your provider cannot use a CA-125 to screen for ovarian cancer if you aren’t at high risk.” Medicare’s policy goes further and lists no screening use at all, high risk or otherwise, so a CA 125 ordered for screening has no covered indication under it. NCI says studies of tumor markers as screening tests “have generally found that these markers do not work well for screening.”

Does a high CA 125 mean cancer? Not by itself. MedlinePlus says “high CA-125 levels don’t always mean ovarian cancer,” and NCI says “noncancerous conditions can sometimes cause an increase in the level of a tumor marker.” NCI says marker results “are usually combined with the results of other tests, such as biopsies or imaging, to diagnose cancer.” What your result means is a conversation with your doctor.

What is the difference between CA 15-3 and CA 27.29? Medicare’s policy treats them as interchangeable: “CA 27.29 is equivalent to CA 15-3 in its usage in management of patients with breast cancer.” They share CPT code 86300 and the same Medicare rate. The one rule is to pick one and stay with it: “use consistently either CA 15-3 or CA 27.29, not both.”

Do you have to fast for a CA 125 test? No. MedlinePlus says “you don’t need any special preparations for a CA-125 blood test,” Cleveland Clinic says “you don’t need to do anything to prepare,” and Quest’s directory lists no patient preparation for any of the three markers.

Sources and data dates

Medicare payment amounts: CMS Clinical Laboratory Fee Schedule, 2026 Q3 file (national rates for 86304 and 86300). Coverage rules: CMS Medicare Coverage Database, NCD 190.28 (CA 125) and NCD 190.29 (CA 15-3/CA 27.29), national policies identical in every state, and the same text in the NCD Manual, Chapter 1, Part 3. Test descriptions, preparation, and ranges: National Cancer Institute (Tumor Markers fact sheet and list), MedlinePlus (CA-125 Blood Test; Tumor Marker Tests), Cleveland Clinic (CA-125 Blood Test), Quest tests 29256, 5819, and 29493, Labcorp tests 002303, 143404, and 140293. 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.