Key facts for NCD 100.3
- Benefit category
- Diagnostic Tests (other)
- Effective date
- 06/11/1985
- Transmittal
- n/a
- Versions published
- 1
- Manual chapter
- 100
- NCD Manual (Pub. 100-03)
TL;DR
NCD 100.3 sets Medicare's national policy for 24-hour ambulatory esophageal ph monitoring under the benefit category "Diagnostic Tests (other)", effective 06/11/1985. Twenty-four hour ambulatory pH monitoring is covered by Medicare for patients who are suspected of having gastric reflux, but only if the patient presents diagnostic problems associated with atypical symptoms or the patient's symptoms are suggestive of… It has been revised once since publication and binds every Medicare Administrative Contractor nationally.
Item or service described
Twenty-four hour ambulatory esophageal pH monitoring is a diagnostic procedure involving the placement of an indwelling electrode into the lower esophagus of a patient for the purpose of determining the presence of gastric reflux and measuring abnormal esophageal acid exposure.
Indications and limitations of coverage
Twenty-four hour ambulatory pH monitoring is covered by Medicare for patients who are suspected of having gastric reflux, but only if the patient presents diagnostic problems associated with atypical symptoms or the patient's symptoms are suggestive of reflux, but conventional tests have not confirmed the presence of reflux.
Text reproduced from the CMS Medicare Coverage Database record for NCD 100.3 version 1. View the original on cms.gov.
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 100.3
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 100.3
What does NCD 100.3 cover?
Twenty-four hour ambulatory pH monitoring is covered by Medicare for patients who are suspected of having gastric reflux, but only if the patient presents diagnostic problems associated with atypical symptoms or the patient's symptoms are suggestive of reflux, but conventional tests have not confirmed the presence of reflux. The full indications and limitations are reproduced on this page from the CMS Medicare Coverage Database.
When did NCD 100.3 take effect?
The current version (1) is effective 06/11/1985. This is the only published version.
Does a Local Coverage Determination override NCD 100.3?
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).
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…
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.