D0419 is the CDT code for the assessment of salivary flow by measurement. The procedure involves collecting saliva under controlled conditions and quantifying output to evaluate salivary gland function. It is used to identify hyposalivation or xerostomia and to establish a baseline for patients at elevated caries risk due to reduced salivary flow.
Get help with D0419 claims →Last updated June 2026 · Reviewed by the PracticeAlpha billing team
Use D0419 when a patient reports xerostomia and you need to objectively quantify salivary output. Subjective complaints alone are not sufficient for a reliable diagnosis. Measurement distinguishes true hyposalivation from perceived dryness and guides treatment decisions.
Patients with multiple new carious lesions, especially on root surfaces or smooth surfaces, may have reduced salivary flow as a contributing factor. Quantifying flow rate helps identify the cause and supports a preventive treatment plan, including prescription fluoride or saliva substitutes.
Many medications reduce salivary output, including antihistamines, antidepressants, antihypertensives, and anticholinergics. Patients with Sjogren's syndrome, diabetes, or post-radiation changes to salivary glands are also candidates. D0419 provides objective data to share with the patient's physician when coordinating care.
Not all dental plans include D0419 as a covered benefit. Some classify it as an experimental or non-covered diagnostic test. Verify coverage before performing the test. If it is not covered, inform the patient in advance so they are not surprised by an out-of-pocket charge.
Many payers require a brief explanation of why salivary flow measurement was clinically necessary. A claim without a supporting narrative or clinical notes may be denied as lacking medical justification. Attach a narrative describing the patient's symptoms, medications, or conditions that prompted the test.
Some plans bundle D0419 into the evaluation fee and will not pay it separately on the same date of service. Check the patient's plan for bundling language before billing both on the same claim.
If the clinical note does not describe the collection method, duration, or measured output, the claim may be denied upon records request. Document the test fully: collection method, stimulated vs. unstimulated, duration, volume collected, and interpretation.
Document the patient's complaint or clinical finding that prompted the test: dry mouth symptoms, high caries risk, relevant medications, or systemic conditions.
Specify whether stimulated or unstimulated flow was measured and the collection technique used (draining, spitting, swabbing, or aspiration).
Record the time period over which saliva was collected. Standard protocols typically collect over a 5- or 15-minute period.
Record the volume collected, the calculated flow rate, and the reference range used to classify the result as normal, low, or very low.
Note how the result influenced the treatment plan: prescription fluoride, saliva substitutes, referral to a physician, or modification of an existing preventive protocol.
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Learn about our billing servicesD0419 is the CDT code for the assessment of salivary flow by measurement. It involves collecting and quantifying saliva to evaluate salivary gland function and identify hyposalivation.
Use D0419 for patients with dry mouth complaints, those on medications that reduce salivary flow, patients with Sjogren's syndrome, or patients post-radiation to the head and neck region.
D0431 is a caries susceptibility test that evaluates bacterial activity in saliva. D0419 measures the volume of salivary output. They serve different diagnostic purposes and can be billed separately when both are performed.
Coverage varies by plan. Many PPOs include it as a diagnostic benefit, but some classify it as non-covered. Always verify benefits and inform the patient before the test if it may not be covered.
Document the clinical indication, collection method (stimulated or unstimulated), collection duration, measured volume and flow rate, interpretation against reference ranges, and the impact on the treatment plan.
Generally yes, but check the patient's plan for bundling rules. Some plans bundle diagnostic tests performed at the same visit. A supporting narrative attached to the claim reduces the chance of denial.
Search all CDT codes in our dental coding guide.