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Frequently Asked Questions
  1. What is medical necessity?

  2. How do I bill for tests which I believe will be denied because the patient’s diagnosis is not covered under either national or local coverage policy?

  3. What if ionized calcium is not medically necessary and I don’t want to run it with the other tests on a Chem 8+ cartridge?

  4. How do I bill for additional Hct or glucose tests that are run for the same patient on the same day?

  5. Why can't I use the CPT code for a Basic Metabolic Panel (80048) when I run a Chem 8 cartridge?

  6. Can an imaging center bill Medicare for creatinine tests using the I-STAT?

  7. Can I bill for collecting blood when I run tests on the I-STAT?

What is medical necessity?

All tests reimbursed by Medicare and most other payers must be medically necessity for the treatment of an injury, illness or malformed body part.

Medicare uses National Coverage Determinations (NCDs) and Local Coverage Determinations (LCDs) to define medical necessity. NCDs and LCDs for many clinical tests list the exact diagnosis (ICD-9) codes which will be accepted for payment.

When neither an NCD or LCD exists, the decision as to what tests are medical necessity for any given patient is left to the judgement of the physician and must be supported by the patient’s medical record.

For example, no NCD exists for ionized calcium. However, 12 Medicare carriers have published local coverage determinations for ionized calcium.

How do I bill for tests which I believe will be denied because the patient’s diagnosis is not covered under either national or local coverage policy?

When an NCD or LCD applies, and the appropriate diagnosis code is not listed as a covered code, a signed Advance Beneficiary Notice (ABN) should be obtained from the patient prior to performing the test. The ABN informs that patient that if the test is denied they are responsible for payment. A properly signed ABN which lists the specific test or service you believe may be denied as well as the reason for probable denial must be obtained in order to bill the patient for a service that is later denied.

What if ionized calcium is not medically necessary and I don’t want to run it with the other tests on a Chem 8+ cartridge?

An ionized calcium test should not be performed and billed if it is not medically necessary. The ionized test function can be “turned off” when running an iSTAT Chem 8+ cartridge so that no test result is reported. See your Operator’s Manual for how to do this.

How do I bill for additional Hct or glucose tests are run for the same patient on the same day?

Repeat tests performed on the same day (date of service) must be identified by using the CPT codifier –59 with the appropriate test code. This modifier indicates that the test is a separate and distinct medically necessary service and not a duplicate test.

Why can't I use the CPT code for a Basic Metabolic Panel (80048) when I run a Chem 8 cartridge?

Answer: CPT code 80048 (Basic Metabolic Panel, total calcium) can be used only when each of the following eight tests are performed: total calcium, carbon dioxide, chloride, creatinine, glucose, potassium, sodium and BUN. The Chem 8 cartridge measures ionized calcium, not total calcium; thus CPT code 80047 (Basic Metabolic Panel, ionized calcium) must be used.

Can an imaging center bill Medicare for creatinine tests using the I-STAT?

Answer: Yes. You will need a CLIA Certificate of Waiver or CLIA Moderate or High Complexity Certificate. Be sure to include your CLIA number in Item 23 of the CMS 1500 form (or its electronic equivalent). The test is billed using CPT code 82565 (Creatinine, blood) with a QW modifier. Since there is no co-pay for clinical laboratory tests, you will receive the entire fee schedule amount, the patient pays nothing.

Can I bill for collecting blood when I run tests on the I-STAT?

Answer: Medicare pays $3.00 for blood collection by venipuncture. Use CPT code 36415. (Collection of venous blood by venipuncture). Only one specimen collection fee is allowed, no matter how many tubes are drawn or how many different tests are performed on the specimen. Capillary blood collection is reported using 36416 (Collection of capillary blood specimen (e.g., finger, heel, ear stick).  Medicare does not cover capillary blood collection, however, some private payers do.

1Reimbursement information source: Centers for Medicare and Medicaid Clinical Diagnostic Laboratory Fee Schedule (CLFS) 2025, available at: https://www.cms.gov/Medicare/Medicare-Fee-for-Service-Payment/ClinicalLabFeeSched/Clinical-Laboratory-Fee-Schedule-Files.html

CLFS does not reflect 2% Payment Adjustment (Sequestration). Click here for more information.

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