How To Use CPT Code 83735

CPT 83735 refers to a laboratory test that measures the amount of magnesium in a patient specimen, and this article will cover its description, procedure, qualifying circumstances, usage, documentation requirements, billing guidelines, historical information, similar codes, and examples.

1. What is CPT 83735?

CPT 83735 is a code used to represent a laboratory test that measures the amount of magnesium in a patient specimen, such as blood. This test is often ordered by clinicians to evaluate patients for abnormal levels of magnesium, which may be related to various medical conditions, including kidney problems, gastrointestinal issues, muscle problems, low calcium or potassium levels, and abnormal heart rhythm.

2. 83735 CPT code description

The official description of CPT code 83735 is: “Magnesium.”

3. Procedure

1. The patient’s specimen, typically blood, is collected.
2. The specimen is sent to the laboratory for analysis.
3. The lab analyst performs a test to measure the amount of magnesium in the specimen, often using a methodology such as mass spectrometry.
4. The sample is vaporized and ionized in the mass spectrometry instrument.
5. Electromagnetic fields separate the ions according to their mass-to-charge ratio.
6. A detector measures the ions, providing data for calculating the amount of specific components present in the sample, including magnesium.
7. The results are reported to the ordering clinician for interpretation and further management of the patient’s condition.

4. Qualifying circumstances

Patients who are eligible to receive CPT code 83735 services are those who require evaluation for abnormal levels of magnesium due to suspected or confirmed medical conditions, such as kidney problems, gastrointestinal issues, muscle problems, low calcium or potassium levels, and abnormal heart rhythm. The ordering clinician must determine the medical necessity of the test based on the patient’s signs, symptoms, and medical history.

5. When to use CPT code 83735

It is appropriate to bill the 83735 CPT code when a clinician orders a laboratory test to measure the amount of magnesium in a patient specimen for the purpose of evaluating the patient for abnormal levels of magnesium related to various medical conditions. The test must be medically necessary and supported by the patient’s signs, symptoms, and medical history.

6. Documentation requirements

To support a claim for CPT 83735, the following information must be documented:

• Patient’s demographic information, including name, date of birth, and insurance information.
• Ordering clinician’s information, including name, contact details, and National Provider Identifier (NPI) number.
• Date and time of the specimen collection.
• Type of specimen collected (e.g., blood).
• Medical necessity for the test, including relevant signs, symptoms, and medical history.
• Results of the magnesium test, including the measured value and reference range.
• Interpretation of the test results by the ordering clinician and any subsequent management or treatment plans.

7. Billing guidelines

When billing for CPT code 83735, it is essential to follow the specific guidelines and rules set by the payer. Some payers may pay separately for collecting the specimen using a code such as 36415, Collection of blood by venipuncture. Additionally, ensure that the claim includes all the required documentation to support the medical necessity of the test and the accuracy of the billed code.

8. Historical information

CPT 83735 was added to the Current Procedural Terminology system on January 1, 1990. There have been no updates to the descriptor since its addition.

9. Similar codes to CPT 83735

Five similar codes to CPT 83735 and how they differentiate from it are:

• CPT 83718: This code is used for measuring the amount of lipoprotein in a patient specimen, rather than magnesium.
• CPT 83721: This code represents a test for measuring the amount of lipoprotein (direct measurement) in a patient specimen, not magnesium.
• CPT 83789: This code is used for mass spectrometry and tandem mass spectrometry procedures, which may be a part of the methodology used in CPT 83735 but is not specific to magnesium measurement.
• CPT 83825: This code is for measuring the amount of mercury in a patient specimen, not magnesium.
• CPT 83835: This code represents a test for measuring the amount of methotrexate in a patient specimen, rather than magnesium.

10. Examples

Here are 10 detailed examples of CPT code 83735 procedures:

1. A patient with chronic kidney disease requires monitoring of their magnesium levels to assess the effectiveness of their treatment plan.
2. A patient with a history of gastrointestinal issues presents with symptoms of muscle weakness, and the clinician orders a magnesium test to evaluate the possible cause.
3. A patient with a known electrolyte imbalance requires a magnesium test to determine if their magnesium levels have returned to normal after treatment.
4. A patient with a suspected abnormal heart rhythm undergoes a magnesium test as part of their diagnostic workup.
5. A patient with a history of alcohol abuse presents with symptoms of tremors and confusion, and the clinician orders a magnesium test to assess their electrolyte status.
6. A patient with malabsorption issues due to a gastrointestinal disorder requires a magnesium test to monitor their nutritional status.
7. A patient with a history of hypocalcemia undergoes a magnesium test to evaluate the possible cause of their low calcium levels.
8. A patient with a suspected magnesium deficiency due to chronic use of certain medications undergoes a magnesium test as part of their evaluation.
9. A patient with a history of hypokalemia requires a magnesium test to determine if their low potassium levels are related to abnormal magnesium levels.
10. A patient with a suspected metabolic disorder undergoes a magnesium test as part of their diagnostic workup.