Key facts for NCD 190.32
- Benefit category
- Diagnostic Laboratory Tests
- Effective date
- 11/25/2002
- Implemented 01/01/2003
- Transmittal
- Transmittal 17
- Versions published
- 1
- Manual chapter
- 190
- NCD Manual (Pub. 100-03)
- Lab edit list
- 3,992 covered ICD-10
- 245 non-covered
TL;DR
NCD 190.32 sets Medicare's national policy for gamma glutamyl transferase under the benefit category "Diagnostic Laboratory Tests", effective 11/25/2002 and implemented 01/01/2003. • To provide information about known or suspected hepatobiliary disease, for example: As a laboratory NCD it carries a national ICD-10 edit list: 3,992 diagnosis codes support medical necessity and 245 are denied, applied automatically by every Medicare contractor to 1 procedure code.
Item or service described
Gamma Glutamyl Transferase (GGT) is an intracellular enzyme that appears in blood following leakage from cells. Renal tubules, liver, and pancreas contain high amounts, although the measurement of GGT in serum is almost always used for assessment of hepatobiliary function. Unlike other enzymes which are found in heart, skeletal muscle, and intestinal mucosa as well as liver, the appearance of an elevated level of GGT in serum is almost always the result of liver disease or injury. It is specifically useful to differentiate elevated alkaline phosphatase levels when the source of the alkaline phosphatase increase (bone, liver, or placenta) is unclear. The combination of high alkaline phosphatase and a normal GGT does not, however, rule out liver disease completely.
As well as being a very specific marker of hepatobiliary function, GGT is also a very sensitive marker for hepatocellular damage. Abnormal concentrations typically appear before elevations of other liver enzymes or bilirubin are evident. Obstruction of the biliary tract, viral infection (e.g., hepatitis, mononucleosis), metastatic cancer, exposure to hepatotoxins (e.g., organic solvents, drugs, alcohol), and use of drugs that induce microsomal enzymes in the liver (e.g., cimetidine, barbiturates, phenytoin, and carbamazepine) all can cause a moderate to marked increase in GGT serum concentration. In addition, some drugs can cause or exacerbate liver dysfunction (e.g., atorvastatin, troglitazone, and others as noted in FDA Contraindications and Warnings.)
GGT is useful for diagnosis of liver disease or injury, exclusion of hepatobiliary involvement related to other diseases, and patient management during the resolution of existing disease or following injury.
Indications and limitations of coverage
Indications
• To provide information about known or suspected hepatobiliary disease, for example:
• Following chronic alcohol or drug ingestion.
• Following exposure to hepatotoxins.
• When using medication known to have a potential for causing liver toxicity (e.g., following the drug manufacturer's recommendations).
• Following infection (e.g., viral hepatitis and other specific infections such as amoebiasis, tuberculosis, psittacosis, and similar infections).
• To assess liver injury/function following diagnosis of primary or secondary malignant neoplasms.
• To assess liver injury/function in a wide variety of disorders and diseases known to cause liver involvement (e.g., diabetes mellitus, malnutrition, disorders of iron and mineral metabolism, sarcoidosis, amyloidosis, lupus, and hypertension).
• To assess liver function related to gastrointestinal disease.
• To assess liver function related to pancreatic disease.
• To assess liver function in patients subsequent to liver transplantation.
• To differentiate between the different sources of elevated alkaline phosphatase activity.
Limitations
When used to assess liver dysfunction secondary to existing non-hepatobiliary disease with no change in signs, symptoms, or treatment, it is generally not necessary to repeat a GGT determination after a normal result has been obtained unless new indications are present.
If the GGT is the only "liver" enzyme abnormally high, it is generally not necessary to pursue further evaluation for liver disease for this specific indication.
When used to determine if other abnormal enzyme tests reflect liver abnormality rather than other tissue, it generally is not necessary to repeat a GGT more than one time per week.
Because of the extreme sensitivity of GGT as a marker for cytochrome oxidase induction or cell membrane permeability, it is generally not useful in monitoring patients with known liver disease.
Note: Scroll down for links to the quarterly Covered Code Lists (including narrative).
Text reproduced from the CMS Medicare Coverage Database record for NCD 190.32 version 1. View the original on cms.gov.
Laboratory NCD code lists (January 2026)
Medicare contractors apply this NCD through a national edit: the procedure codes below are paid only when the claim carries a covered diagnosis. The January 2026 list holds 3,992 covered and 245 non-covered ICD-10-CM codes plus 30 codes with other resolution rules.
1 procedure code are edited against this NCD's diagnosis list. CPT codes are shown as numbers only; descriptors are licensed by the AMA.
| Code | Code set |
|---|---|
| 82977 | CPT (descriptor licensed by AMA) |
The first 40 of 3,992 covered diagnosis codes, with FY2027 ICD-10-CM descriptions. A claim with any covered code on the line supports medical necessity under the national edit.
| ICD-10-CM | Description | Effective |
|---|---|---|
| A021 | Salmonella sepsis | 2015-10-01 |
| A060 | Acute amebic dysentery | 2015-10-01 |
| A061 | Chronic intestinal amebiasis | 2015-10-01 |
| A062 | Amebic nondysenteric colitis | 2015-10-01 |
| A063 | Ameboma of intestine | 2015-10-01 |
| A064 | Amebic liver abscess | 2015-10-01 |
| A065 | Amebic lung abscess | 2015-10-01 |
| A066 | Amebic brain abscess | 2015-10-01 |
| A067 | Cutaneous amebiasis | 2015-10-01 |
| A0681 | Amebic cystitis | 2015-10-01 |
| A0682 | Other amebic genitourinary infections | 2015-10-01 |
| A0689 | Other amebic infections | 2015-10-01 |
| A069 | Amebiasis, unspecified | 2015-10-01 |
| A1783 | Tuberculous neuritis | 2015-10-01 |
| A179 | Tuberculosis of nervous system, unspecified | 2015-10-01 |
| A1831 | Tuberculous peritonitis | 2015-10-01 |
| A1832 | Tuberculous enteritis | 2015-10-01 |
| A1839 | Retroperitoneal tuberculosis | 2015-10-01 |
| A1882 | Tuberculosis of other endocrine glands | 2015-10-01 |
| A1883 | Tuberculosis of digestive tract organs, not elsewhere classified | 2015-10-01 |
| A1884 | Tuberculosis of heart | 2015-10-01 |
| A1889 | Tuberculosis of other sites | 2015-10-01 |
| A199 | Miliary tuberculosis, unspecified | 2015-10-01 |
| A200 | Bubonic plague | 2015-10-01 |
| A201 | Cellulocutaneous plague | 2015-10-01 |
| A202 | Pneumonic plague | 2015-10-01 |
| A203 | Plague meningitis | 2015-10-01 |
| A207 | Septicemic plague | 2015-10-01 |
| A208 | Other forms of plague | 2015-10-01 |
| A209 | Plague, unspecified | 2015-10-01 |
| A227 | Anthrax sepsis | 2015-10-01 |
| A260 | Cutaneous erysipeloid | 2015-10-01 |
| A267 | Erysipelothrix sepsis | 2015-10-01 |
| A268 | Other forms of erysipeloid | 2015-10-01 |
| A269 | Erysipeloid, unspecified | 2015-10-01 |
| A270 | Leptospirosis icterohemorrhagica | 2015-10-01 |
| A301 | Tuberculoid leprosy | 2015-10-01 |
| A320 | Cutaneous listeriosis | 2015-10-01 |
| A3211 | Listerial meningitis | 2015-10-01 |
| A3212 | Listerial meningoencephalitis | 2015-10-01 |
245 diagnosis codes deny automatically under this NCD; the first 20 are shown.
| ICD-10-CM | Description |
|---|---|
| R99 | Ill-defined and unknown cause of mortality |
| Z0000 | Encounter for general adult medical examination without abnormal findings |
| Z0001 | Encounter for general adult medical examination with abnormal findings |
| Z00110 | Health examination for newborn under 8 days old |
| Z00111 | Health examination for newborn 8 to 28 days old |
| Z00121 | Encounter for routine child health examination with abnormal findings |
| Z00129 | Encounter for routine child health examination without abnormal findings |
| Z005 | Encounter for examination of potential donor of organ and tissue |
| Z006 | Encounter for examination for normal comparison and control in clinical research program |
| Z0070 | Encounter for examination for period of delayed growth in childhood without abnormal findings |
| Z0071 | Encounter for examination for period of delayed growth in childhood with abnormal findings |
| Z008 | Encounter for other general examination |
| Z020 | Encounter for examination for admission to educational institution |
| Z021 | Encounter for pre-employment examination |
| Z022 | Encounter for examination for admission to residential institution |
| Z023 | Encounter for examination for recruitment to armed forces |
| Z024 | Encounter for examination for driving license |
| Z025 | Encounter for examination for participation in sport |
| Z026 | Encounter for examination for insurance purposes |
| Z0271 | Encounter for disability determination |
Revision history
07/2004 - Published NCD in the NCD Manual without change to narrative contained in PM AB-02-110. Coding guidance now published in Medicare Lab NCD Manual. Effective and Implementation dates NA. ( TN 17 ) (CR 2130)
07/2002 - Implemented NCD. Effective date 11/25/02. Implementation date 1/01/03. ( TN AB-02-110 ) (CR 2130)
How this NCD shows up on remittances
A service denied under a National Coverage Determination returns CARC 50 (not deemed medically necessary) with remark N386 (decision based on an NCD); a denial citing a local policy instead carries N115. Because NCDs bind nationally, the appeal path is documentation that the patient meets the indications above, not a contractor-policy argument.
How QuickIntell applies NCD 190.32
QuickAuth checks the ordered service and diagnosis against NCD and LCD criteria before the encounter, QuickCode validates the diagnosis pairing on the claim, and QuickRCM routes CARC 50 denials with the policy text and the covered-code list attached so the appeal starts with evidence.
Frequently asked questions — NCD 190.32
What does NCD 190.32 cover?
• To provide information about known or suspected hepatobiliary disease, for example: The full indications and limitations are reproduced on this page from the CMS Medicare Coverage Database.
When did NCD 190.32 take effect?
The current version (1) is effective 11/25/2002, implemented 01/01/2003, published in transmittal 17. This is the only published version.
Does a Local Coverage Determination override NCD 190.32?
No. A National Coverage Determination binds all Medicare Administrative Contractors; an LCD can only address services or circumstances the NCD leaves open. Claims denied under this NCD typically return CARC 50 with remark N386 (NCD) rather than N115 (LCD).
Which diagnosis codes are covered under NCD 190.32?
The January 2026 laboratory NCD edit list contains 3,992 ICD-10-CM codes that support gamma glutamyl transferase (for example A021 Salmonella sepsis; A060 Acute amebic dysentery; A061 Chronic intestinal amebiasis) and 245 codes that deny. The list applies to 82977.
How often does the lab NCD code list for 190.32 change?
CMS updates the laboratory NCD edit module quarterly, with the January release carrying the annual ICD-10-CM code changes. Codes added or deleted mid-year appear in the quarterly change spreadsheets on the Lab NCDs page.
Sources
Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-02. Verify against the primary file before billing or contracting decisions.
- Medicare Coverage Database NCDs via the CMS Coverage APIVersion API snapshot 2026-09-27 · effective 2026-09-20 · file national-coverage-ncd.jsonSHA-256 a90fadfd264b9ef4…
- Laboratory NCD ICD-10 code lists, January 2026Version January 2026 · effective 2026-01-01 · file 2026100-Initial-ICD10-NCD-Spreadsheet-20250721-508.xlsxSHA-256 57ff5cd37ba523d3…
- ICD-10-CM FY2027 code descriptionsVersion FY2027 · effective 2026-10-01 · file icd10cm_codes_2027.txtSHA-256 3c0583a38ee0e848…
Disclaimer
This page reproduces the CMS National Coverage Determination text and, for laboratory NCDs, the CMS ICD-10 edit lists, as an operational reference. Coverage decisions depend on the full policy, the claim and the contractor; nothing here is legal, clinical or billing advice. CPT codes are shown as numbers only; CPT descriptors are copyright AMA.