CPT 85576Laboratory

Blood platelet aggregation

CPT code 85576 covers laboratory testing that measures how well blood platelets clump together (aggregate), which is essential for diagnosing bleeding disorders and monitoring patients on antiplatelet medications like aspirin or Plavix.

Showing rates for

National Average

Base Medicare rate

$17.14

This calculator gives a typical-case estimate using standard Medicare modifier rules. Actual payment depends on payer policies, documentation, code-specific CMS status indicators, and locality. Verify before billing.

RVU breakdown

Work RVU

0.37

PE RVU (NF)

0.15

MP RVU

0.01

Total RVU

0.53

Conversion factor: 32.3465 · Source: CMS MPFS RVU25A · Confidence: High

NCCI bundling edits

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Billing tips

Document the specific medical necessity for platelet aggregation testing, including the clinical indication (bleeding symptoms, medication monitoring, or pre-surgical assessment) and prior test results if applicable
Impact: Reduces denial rate by approximately 35-40% as payers frequently request medical necessity documentation for specialized coagulation studies
Specify the aggregating agents used (ADP, collagen, epinephrine, ristocetin, arachidonic acid) in the laboratory report, as some payers may require documentation of multiple agonists for full reimbursement
Impact: Ensures full $17.14 payment and supports medical necessity; incomplete testing may result in reduced payment or denial
When monitoring antiplatelet therapy, limit testing frequency to quarterly or as medically justified with documented clinical changes, as excessive frequency triggers payer audits
Impact: Medicare and commercial payers often deny claims for testing performed more frequently than quarterly without documented clinical indication
Link appropriate ICD-10 diagnosis codes that support medical necessity, such as D69.1 (qualitative platelet defects), Z79.02 (long-term antiplatelet therapy), or hemorrhagic condition codes
Impact: Improper diagnosis coding accounts for 25-30% of denials; correct linkage ensures clean claims processing
Do not routinely bill 85576 with comprehensive coagulation panels unless each test has distinct medical necessity; consider unbundling risks with codes like 85732
Impact: Prevents bundling denials and potential recoupment; improper bundling can result in loss of $10-15 per claim
Verify patient medication list includes antiplatelet agents or anticoagulants when billing for therapeutic monitoring, as lack of documented medication triggers payer scrutiny

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Frequently asked questions

What is the 2025 Medicare reimbursement rate for CPT code 85576?

The 2025 Medicare national average reimbursement rate for CPT 85576 is $17.14 for both facility and non-facility settings, based on a total RVU of 0.53 and conversion factor of 32.3465.

How often can CPT 85576 be billed for antiplatelet therapy monitoring?

While there is no specific CMS frequency limitation, most payers consider quarterly testing (every 90 days) reasonable for antiplatelet therapy monitoring. More frequent testing requires documented clinical changes, medication adjustments, bleeding events, or pre-surgical assessment to establish medical necessity.

What diagnosis codes support medical necessity for CPT 85576?

Common supporting diagnosis codes include D69.1 (qualitative platelet defects), Z79.02 (long-term use of antithrombotics/antiplatelets), D69.6 (thrombocytopenia unspecified), Z79.01 (long-term use of anticoagulants), and specific hemorrhagic disorder codes. The diagnosis must clearly justify why platelet function testing is medically necessary.

Can CPT 85576 be billed together with other coagulation tests?

Yes, CPT 85576 can be billed with other coagulation studies when each test serves a distinct clinical purpose. However, be cautious of bundling edits with comprehensive panels. Use modifier 59 when necessary to indicate distinct procedural services and ensure documentation supports the medical necessity of each separate test.

What is the difference between CPT 85576 and 85597?

CPT 85576 covers blood platelet aggregation studies (traditional platelet function testing), while CPT 85597 is for platelet neutralization, a different type of coagulation study used primarily in lupus anticoagulant evaluation. These tests measure different aspects of platelet and coagulation function and are not interchangeable.

Do I need a modifier when billing 85576 for repeat testing on the same day?

Yes, use modifier 91 when performing repeat platelet aggregation testing on the same day for clinical monitoring purposes, such as assessing response to therapy adjustments. Alternatively, modifier 76 may be appropriate for repeat procedures by the same physician. Without the appropriate modifier, the duplicate claim will likely deny.

What RVU values are assigned to CPT 85576 in 2025?

For 2025, CPT 85576 has a Work RVU of 0.37, Practice Expense RVU of 0.15 (both facility and non-facility), and Malpractice RVU of 0.01, totaling 0.53 total RVUs. These values, multiplied by the 2025 conversion factor of 32.3465, yield the Medicare payment rate of $17.14.