CPT (Current Procedural Terminology) codes are five-digit numbers that describe every medical service or procedure. Your doctor, hospital, and insurance company use them to communicate exactly what was done. Every line on your medical bill has a CPT code, and knowing the code lets you look up what Medicare pays for that same service.

Why do providers charge so much more than Medicare pays?

Providers set their own "chargemaster" prices, which are essentially list prices. Medicare pays a fixed rate based on the resources each service actually requires (the RVU system for procedures, or the Clinical Lab Fee Schedule for lab tests). Commercial insurers typically pay 150% to 250% of Medicare rates. Uninsured patients are often billed the full chargemaster price, which can be 2x to 30x what Medicare pays.

Can I use Medicare rates to negotiate my bill?

Yes. Medicare rates are the closest thing to a "fair price" benchmark in U.S. healthcare. When negotiating, ask the provider what they accept from Medicare for the same CPT code. Most providers will accept 150% to 200% of Medicare for cash-pay patients, which is still far less than their chargemaster price. Many hospital financial assistance policies also use a multiple of Medicare as their discount floor.

How are Medicare rates calculated?

For most procedures, Medicare uses the Resource-Based Relative Value Scale (RBRVS). Each CPT code gets three RVU components: Work (physician time and skill), Practice Expense (overhead), and Malpractice. These are multiplied by geographic adjustment factors (GPCIs) and a conversion factor ($33.4009 in 2026). Lab tests (80000-89999 range) use a separate Clinical Laboratory Fee Schedule with flat national rates.

CPT 88342

Immunohistochemistry (IHC), First Antibody Stain

CPT 88342 covers the first immunohistochemistry (IHC) antibody stain performed on a tissue sample. IHC stains use antibodies to identify specific proteins in tissue, helping pathologists determine cancer type, origin, and treatment targets. Providers charge an average of $210.64, with Medicare paying $110.22 (1.9x markup). What patients often do not realize is that each additional stain (CPT 88341) is billed separately at $150+, and cancer pathology typically requires 4 to 10 or more stains, generating $600 to $1,500+ in pathology charges on top of the base tissue examination.

Updated May 2026Source: CMS Physician Fee Schedule

CPT 88342 at a Glance

Average provider charge: $210.64
Medicare rate (office and facility): $110.22
Typical markup: 1.9x over Medicare
Each additional stain (88341): ~$150+ charge

Common use: Cancer type and treatment planning
Typical stains per case: 4 to 10+
Performed by: Pathology lab
Beneficiaries (2023): 720,208

How the Medicare Rate Is Calculated

Medicare values every procedure using Relative Value Units (RVUs) across three components, then multiplies by a national conversion factor of $33.4009 (2026). IHC staining has a high practice expense RVU because it requires specialized reagents, equipment, and lab technician time:

Component	What It Covers	Office (Non-Facility)	Hospital (Facility)
Work RVU	Pathologist time, skill, and judgment	0.73	0.73
Practice Expense RVU	Lab equipment, reagents, technician time	2.44	2.44
Malpractice RVU	Professional liability insurance	0.02	0.02
Total RVU		3.19	3.19
x $33.4009	2026 conversion factor	$110.22	$110.22

Why the markup is relatively modest (1.9x): Unlike simple tests like bladder scans, IHC staining has genuine overhead costs (specialized antibody reagents at $50 to $200 per vial, automated staining equipment, trained histotechnologists). The 1.9x markup is one of the lower markups in this guide. However, the cumulative cost across multiple stains per case is what catches patients off guard.

Total Pathology Cost: What to Expect After a Biopsy

Patients rarely see pathology charges coming because they happen in the lab after the biopsy. Here is a breakdown of what a typical cancer pathology workup costs:

Service	CPT Code	Avg. Charge	Medicare Rate
Tissue examination (surgical pathology)	88305	~$182	~$100
First IHC stain	88342	$211	$110
Each additional IHC stain (x3 to x9)	88341	~$150 each	~$95 each
Breast cancer example (4 stains: ER, PR, HER2, Ki-67)		~$843	~$495
Complex case (8 stains)		~$1,443	~$875

This is clinically necessary. While the costs are high, IHC staining is essential for cancer treatment planning. Knowing whether breast cancer is ER-positive, HER2-positive, or triple-negative directly determines which drugs will be effective. Skipping these stains would mean treating blindly. The goal is not to avoid the testing, but to understand the charges so you can verify accuracy and plan financially.

Medicare Rate by State

Medicare adjusts the national rate by location using Geographic Practice Cost Indices (GPCIs). Because 88342 has a high practice expense component (lab costs), geographic variation is meaningful in dollar terms (roughly $80 to $102).

Medicare Rate by State (2026)

Medicare adjusts payments by location using Geographic Practice Cost Indices (GPCIs). Select your state to see the adjusted rate.

Sample State Rates

State	Medicare Pays	Avg. Charge	Markup
Texas (Austin)	$88.28	$210.64	2.4x
California (Los Angeles)	$93.78	$210.64	2.2x
New York (Manhattan)	$94.08	$210.64	2.2x
Florida (Fort Lauderdale)	$88.95	$210.64	2.4x
Ohio	$83.25	$210.64	2.5x
Mississippi	$80.15	$210.64	2.6x
Arkansas	$79.67	$210.64	2.6x
Alaska	$101.59	$210.64	2.1x

Rates shown use 2026 GPCIs and the $33.4009 conversion factor. The average provider charge of $210.64 is the 2023 national average from CMS utilization data. Actual charges vary by provider.

Common Billing Problems with 88342

Out-of-network pathologist surprise bills

The pathologist who reads your biopsy is almost always a different provider than your surgeon. They may be out-of-network with your insurance, even if your surgeon and the hospital are in-network. The No Surprises Act (effective January 2022) protects you: if the pathology was performed at an in-network facility, you should not be billed more than your in-network cost-sharing amount, regardless of the pathologist's network status. If you receive a balance bill from an out-of-network pathologist, cite the No Surprises Act.

Unexpected pathology charges after biopsy

Many patients are blindsided by pathology bills because no one mentions the cost in advance. Your surgeon performs the biopsy, sends the tissue to the lab, and weeks later you receive a separate bill from the pathology group for $600 to $1,500+. While these charges are legitimate (you need the analysis for treatment decisions), you should know to expect them. Ask your surgeon's office before the biopsy approximately how many stains will be needed and who the pathology group is, so you can verify network status.

Excessive number of stains

While 4 to 6 stains is common for straightforward cancer cases, some pathology labs perform 10 to 15+ stains. More stains are sometimes clinically necessary (for example, when the cancer origin is unknown), but they should be ordered for specific diagnostic reasons. If your bill shows an unusually high number of stains, ask the pathologist's office for the rationale. Each stain should have been ordered to answer a specific clinical question.

Billing 88342 multiple times instead of 88342 + 88341

The first antibody stain is 88342 ($211). Each additional stain on the same specimen should be billed as 88341 (lower rate, approximately $150). If you see 88342 billed multiple times rather than once for 88342 and then 88341 for subsequent stains, this is a coding error that may be inflating your bill. The distinction matters because 88342 has a higher payment rate than 88341.

Frequently Asked Questions

How much does immunohistochemistry (CPT 88342) cost?

The first IHC stain (CPT 88342) has an average provider charge of $210.64. Medicare pays $110.22 (1.9x markup). Each additional stain is billed under CPT 88341 at approximately $150+ per stain. Cancer pathology often requires 4 to 10 or more stains, generating $600 to $1,500+ in pathology charges on top of the base tissue examination (CPT 88305, approximately $182).

Why are multiple IHC stains needed for cancer?

IHC stains use antibodies to identify specific proteins in tissue, helping pathologists determine cancer type, where it originated, and which treatments will work. For breast cancer, common stains include ER (estrogen receptor), PR (progesterone receptor), HER2, and Ki-67. Each stain targets a different protein and is billed separately. This information is clinically necessary because it directly determines which therapies (hormone therapy, targeted therapy, chemotherapy) will be effective for your specific cancer.

Can the pathologist be out-of-network?

Yes. The pathologist who performs IHC staining is almost always a different provider than your surgeon or oncologist, and may be out-of-network with your insurance even when the hospital or surgery center is in-network. The No Surprises Act (effective January 2022) protects you from surprise bills from out-of-network pathologists at in-network facilities. You should not be billed more than your in-network cost-sharing amount. If you receive a balance bill, cite this federal protection.

What is the total pathology cost for a cancer biopsy?

A typical cancer biopsy pathology bill includes the tissue examination (88305, approximately $182 charge), the first IHC stain (88342, $211), and additional stains (88341, approximately $150 each). For breast cancer with 4 IHC stains (ER, PR, HER2, Ki-67), expect roughly $843 in pathology charges. More complex cases requiring 8 to 10 stains can exceed $1,500. These charges are separate from the biopsy procedure itself and often come as a separate bill from the pathology group.

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