Medicare plans to pay less for lab tests starting in 2027. Your lab bill didn't get the memo.

Medicare keeps a price list for lab tests. It’s called the Clinical Laboratory Fee Schedule (CLFS), and it sets what Medicare pays a lab for each blood test, urine test, and panel.

On September 21, 2026, the Centers for Medicare & Medicaid Services (CMS), the federal agency that runs Medicare, released preliminary numbers for 2027. By law, Medicare’s lab rates are based on what private insurers pay. CMS says the new private-insurer data points to rates about 16% lower, on average, than 2026 rates. But no test can be cut more than 15% in a year, so the bigger drops would phase in over 2027–2029.

That sounds like good news for patients. Sometimes it is. Often, it changes nothing about the bill in your mailbox. Here’s why, and what to do about it.

1. What CMS actually released

These are preliminary numbers, not final. Here’s what CMS’s fact sheet says:

• The average potential change from 2026 rates is about 16% lower.
• CMS had enough private-insurer data to set a new figure for 1,528 tests. Of those, 1,171 came in lower than the 2026 rate, 186 higher, and 169 the same.
• No test’s payment can be cut more than 15% a year from 2027 through 2029, so some bigger drops would take several years.
• Final rates come out in November 2026 and take effect January 1, 2027.

Anyone can comment. You don’t need to be a doctor or a lab. CMS allows 30 days after publication. Counting from the September 21 release, that’s about October 21, 2026 — CMS doesn’t list a calendar date, so don’t wait until the last day. Comments go by email to CLFS_Annual_Public_Meeting@cms.hhs.gov. Details are in the CMS fact sheet.

2. What this means for you — and what it doesn’t

Original Medicare track

Here’s the good news most people never hear: if Original Medicare covers a lab test, you usually owe $0. No deductible, no 20% coinsurance, no copay. Medicare pays the lab directly, at Medicare’s rate.

So if your test is covered, a lower Medicare rate doesn’t change your bill. It was already zero.

Here’s the catch. The gap between Medicare’s rate and the lab’s own price matters a lot when:

• Medicare denies the test and you signed an ABN (Advance Beneficiary Notice), the form that says Medicare may not pay and you agree to pay if it doesn’t. Common denial reasons: the diagnosis on the order didn’t match Medicare’s coverage rules, or you had the test too soon after the last one.
• You paid out of pocket (self-pay), so Medicare was never billed.
• You’re in a Medicare Advantage plan and used a lab outside its network (see below).

In those cases, you can be billed the lab’s own price. And its own price is usually nothing like Medicare’s.

Medicare Advantage track

If you’re in a Medicare Advantage (MA) plan, the fee schedule above is Original Medicare’s price list. Your plan sets its own lab network and cost-sharing, so your plan’s Evidence of Coverage — not this fee schedule — decides what you owe. Two things to know:

• ABNs have no effect in Medicare Advantage. What counts there is your plan’s decision and its written denial notice.
• Using a lab outside your plan’s network can lead to a denial or higher costs. Check which labs your plan uses before the draw.

If your plan denies a lab test, you can ask the plan for reconsideration within 65 days of the denial notice. More on Medicare Advantage →

3. How far apart are lab prices and Medicare’s rate?

Stat card — Average lab markup over Medicare’s rate

392% average markup (median 250%) — about 4.9x what Medicare pays.

Population: 97,714 laboratory provider-service records, comparing CY2023 submitted charges to the 2026 Medicare Clinical Laboratory Fee Schedule. Source: GougeStop analysis of CMS data.

Caveat: these are submitted charges — what labs billed, not what anyone actually paid. On a covered Original Medicare test, the patient owes $0. The markup bites when a test is denied and you signed an ABN, or when you pay yourself.

Here’s what Medicare pays in 2026 for some of the most common tests:

Now compare that with what hospitals post. A 2024 study of large Florida hospitals (400 or more beds), published in the journal Cureus, found the average posted hospital price for a CBC was $401, against Medicare’s $7.77. For a comprehensive metabolic panel, it was $957, against $10.56.

4. What happened to me

I’m David Rockaway, founder of Medterpret. I’m on Original Medicare in Texas.

A lab billed me $173 for two tests Medicare values at about $27. On a separate bill, denied tests were charged at $1,183.17 against a Medicare rate of $117.49 — and the provider never produced a signed ABN.

That’s why GougeStop exists. The price list is public. Most patients just never get shown it.

5. Five action steps

Action step 1 — Precheck before the draw. Get a copy of the lab order before your appointment and check it. Is the test covered for the diagnosis listed? Is it too soon since your last one? Medterpret’s Precheck runs that check for you.

Action step 2 — Don’t sign a blank or after-the-fact ABN. (Original Medicare only.) An ABN must be filled in — the specific tests, the reason Medicare may not pay, and a cost estimate — and given to you before the service. If it’s blank, ask staff to fill it in first. If you still want the test, choosing the option that bills Medicare keeps your appeal rights.

Action step 3 — If you’re billed, ask for the signed ABN and an itemized bill. Put it in writing. (Original Medicare:) without a valid ABN signed before the service, you generally owe nothing on a medical-necessity denial. The itemized bill shows exactly which tests you’re being charged for, and at what price.

Action step 4 — Compare with GougeStop’s bill check. Upload the bill. GougeStop shows what you were charged next to what Medicare pays for the same test.

Action step 5 — Negotiate, with Medicare’s rate as the anchor. Call or write the lab’s billing office. Say what Medicare pays for the test and ask them to adjust. GougeStop’s negotiate-a-bill scripts give you the words. There’s no promise of a result — but a public federal rate is a much stronger starting point than “this seems high.” This is how you push back on the bill with facts.

What to do this week

• Comment, if you want to. CMS is taking comments on the 2027 rates until about October 21.
• Pull out any unpaid lab bill. Is it itemized? Is there a signed ABN on file?
• Original Medicare: check your Medicare Summary Notice (MSN). If a test was denied, you have 120 days from receiving the MSN to ask for a redetermination.
• Medicare Advantage: check your plan’s Explanation of Benefits (EOB) and any denial notice. You have 65 days from the denial notice to ask your plan for reconsideration.
• Before your next draw: get the order and run a Precheck.

Bottom line: a lower Medicare rate is a better yardstick. It only helps you if you use it.

Got a lab bill that looks way off? Run it through GougeStop’s bill check to see what Medicare pays for the same tests, then get drafted scripts and documents. Medterpret drafts; you decide what to send. Check a bill →

Got a denial or a confusing notice? Appeal a denial →

Founding members: $69 a year, locked in for as long as you stay a member. Open to the first 500 members or through December 31, 2026, whichever comes first. Reserve My Founding Rate (no card needed). Founding rate →

Medterpret is independent and not affiliated with or endorsed by Medicare, CMS, HHS, or any government agency. Educational information, not legal or medical advice.

Sources

1. “Preliminary Calendar Year (CY) 2027 Medicare Clinical Laboratory Fee Schedule Payment Rates,” fact sheet, Centers for Medicare & Medicaid Services (CMS), September 21, 2026. cms.gov
2. “CMS Announces New Preliminary Medicare Payment Rates for Laboratory Services, Saving Taxpayers an Estimated $1 Billion Annually,” press release, CMS, September 21, 2026. cms.gov
3. “Clinical Laboratory Fee Schedule (CLFS),” CMS, accessed September 29, 2026. cms.gov
4. “Diagnostic laboratory tests,” Medicare.gov, accessed September 29, 2026. medicare.gov
5. “FFS ABN” (Advance Beneficiary Notice of Non-coverage), CMS, accessed September 29, 2026. cms.gov
6. Lin T, Margo CE. “Cost Comparisons of Physician-Ordered Versus Direct-to-Consumer Laboratory Testing,” Cureus, November 21, 2024. pmc.ncbi.nlm.nih.gov
7. “Medicare Physician & Other Practitioners — by Provider and Service” (CY2023 data used in the GougeStop markup analysis), CMS data.cms.gov. data.cms.gov