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Official Description

Lithium

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 80178 refers to a laboratory test specifically designed to measure the levels of lithium in the blood. Lithium, commonly known by its brand names such as Eskalith or Lithobid, is a medication that functions as a neurotransmitter, playing a crucial role in regulating the flow of sodium through nerve and muscle cells. This regulation is particularly important in the management of bipolar disorder, where lithium is utilized to stabilize the manic phase of the condition. Additionally, lithium may be prescribed for other medical issues, including cluster headaches and bipolar depression. Due to its narrow therapeutic range, it is essential to monitor lithium blood levels closely, especially during the initial stages of therapy when the dosage is being adjusted. Blood samples for lithium testing should ideally be drawn 12 hours after the last dose to ensure accurate measurement. The blood sample is collected through a venipuncture, which is a procedure that can be reported separately. Once collected, the serum is analyzed using a method known as reflectance spectrophotometry, which allows for precise quantification of lithium levels in the bloodstream.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The lithium blood test (CPT® Code 80178) is indicated for several specific clinical scenarios, particularly in the management of bipolar disorder and related conditions. The following are the primary indications for performing this test:

  • Bipolar Disorder Management - The test is used to monitor lithium levels in patients undergoing treatment for bipolar disorder, especially during the manic phase.
  • Adjustment of Dosage - Frequent monitoring is necessary when adjusting the dosage of lithium to ensure therapeutic levels are achieved without reaching toxic levels.
  • Suspected Lithium Toxicity - The test is indicated when there is a suspicion of high lithium levels, which can lead to toxicity and adverse effects.
  • Monitoring Maintenance Therapy - Regular intervals of testing are required for patients on maintenance doses of lithium to ensure levels remain within the therapeutic range.
  • Cluster Headaches and Bipolar Depression - The test may also be indicated for patients being treated for cluster headaches or bipolar depression, where lithium is part of the therapeutic regimen.

2. Procedure

The procedure for testing lithium levels involves several key steps that ensure accurate and reliable results. The following outlines the procedural steps involved in the lithium blood test:

  • Step 1: Patient Preparation - Prior to the blood draw, the patient should be informed about the test and the importance of timing. It is crucial that the blood sample is drawn 12 hours after the last dose of lithium to obtain an accurate measurement of the drug's level in the bloodstream.
  • Step 2: Venipuncture - A qualified healthcare professional will perform a venipuncture, which involves inserting a needle into a vein, typically in the arm, to collect a blood sample. This step is essential as it provides the serum needed for testing.
  • Step 3: Sample Handling - Once the blood is drawn, it is collected in a suitable container and handled according to laboratory protocols to prevent contamination or degradation of the sample.
  • Step 4: Laboratory Analysis - The serum is then subjected to analysis using reflectance spectrophotometry, a method that allows for the precise quantification of lithium levels in the blood. This technique measures the amount of light reflected by the sample, which correlates with the concentration of lithium present.
  • Step 5: Result Interpretation - After the analysis is complete, the results are compiled and interpreted by laboratory personnel. The findings are then reported to the healthcare provider, who will use the information to make informed decisions regarding the patient's treatment plan.

3. Post-Procedure

After the blood sample has been collected and sent for analysis, there are a few considerations for post-procedure care. Patients may experience minor discomfort or bruising at the venipuncture site, which typically resolves quickly. It is important for patients to follow any specific instructions provided by their healthcare provider regarding medication adherence and follow-up appointments. The healthcare provider will review the test results and determine if any adjustments to the lithium dosage are necessary based on the measured levels. Regular monitoring is essential to ensure that lithium levels remain within the therapeutic range, thereby minimizing the risk of toxicity and optimizing treatment outcomes.

Short Descr ASSAY OF LITHIUM
Medium Descr DRUG SCREEN QUANTITATIVE LITHIUM
Long Descr Lithium
Status Code Statutory Exclusion (from MPFS, may be paid under other methodologies)
Global Days XXX - Global Concept Does Not Apply
PC/TC Indicator (26, TC) 9 - Not Applicable
Multiple Procedures (51) 9 - Concept does not apply.
Bilateral Surgery (50) 9 - Concept does not apply.
Physician Supervisions 09 - Concept does not apply.
Assistant Surgeon (80, 82) 9 - Concept does not apply.
Co-Surgeons (62) 9 - Concept does not apply.
Team Surgery (66) 9 - Concept does not apply.
Diagnostic Imaging Family 99 - Concept Does Not Apply
CLIA Waived (QW) Yes
APC Status Indicator Conditionally packaged laboratory tests
Type of Service (TOS) 5 - Diagnostic Laboratory
Berenson-Eggers TOS (BETOS) T1H - Lab tests - other (non-Medicare fee schedule)
MUE 2
CCS Clinical Classification 235 - Other Laboratory
90 Reference (outside) laboratory: when laboratory procedures are performed by a party other than the treating or reporting physician or other qualified health care professional, the procedure may be identified by adding modifier 90 to the usual procedure number.
QW Clia waived test
GW Service not related to the hospice patient's terminal condition
77 Repeat procedure by another physician or other qualified health care professional: it may be necessary to indicate that a basic procedure or service was repeated by another physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 77 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
GA Waiver of liability statement issued as required by payer policy, individual case
GX Notice of liability issued, voluntary under payer policy
GY Item or service statutorily excluded, does not meet the definition of any medicare benefit or, for non-medicare insurers, is not a contract benefit
GZ Item or service expected to be denied as not reasonable and necessary
26 Professional component: certain procedures are a combination of a physician or other qualified health care professional component and a technical component. when the physician or other qualified health care professional component is reported separately, the service may be identified by adding modifier 26 to the usual procedure number.
59 Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
76 Repeat procedure or service by same physician or other qualified health care professional: it may be necessary to indicate that a procedure or service was repeated by the same physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 76 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
91 Repeat clinical diagnostic laboratory test: in the course of treatment of the patient, it may be necessary to repeat the same laboratory test on the same day to obtain subsequent (multiple) test results. under these circumstances, the laboratory test performed can be identified by its usual procedure number and the addition of modifier 91. note: this modifier may not be used when tests are rerun to confirm initial results; due to testing problems with specimens or equipment; or for any other reason when a normal, one-time, reportable result is all that is required. this modifier may not be used when other code(s) describe a series of test results (eg, glucose tolerance tests, evocative/suppression testing). this modifier may only be used for laboratory test(s) performed more than once on the same day on the same patient.
GC This service has been performed in part by a resident under the direction of a teaching physician
GV Attending physician not employed or paid under arrangement by the patient's hospice provider
PN Non-excepted service provided at an off-campus, outpatient, provider-based department of a hospital
Q1 Routine clinical service provided in a clinical research study that is in an approved clinical research study
QJ Services/items provided to a prisoner or patient in state or local custody, however the state or local government, as applicable, meets the requirements in 42 cfr 411.4 (b)
X5 Diagnostic services requested by another clinician: for reporting services by a clinician who furnishes care to the patient only as requested by another clinician or subsequent and related services requested by another clinician; this modifier is reported for patient relationships that may not be adequately captured by the above alternative categories; reporting clinician service examples include but are not limited to, the radiologist's interpretation of an imaging study requested by another clinician
XE Separate encounter, a service that is distinct because it occurred during a separate encounter
Date
Action
Notes
2013-01-01 Changed Medium description changed per AMA 2013 corrections document dated January 25, 2013.
1993-01-01 Added First appearance in code book in 1993.
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