How to read a lab report layout

What a lab report usually shows

A lab report is the record the lab that ran your test sends back. Federal CLIA rules (42 CFR 493.1291) say a test report must show the patient's name or another identifier, the name and address of the lab, the report date, the test performed, the specimen source when appropriate, and the result with its units when they apply. The lab's reference intervals must also be available to the person who ordered the test. A report may also show the collection date, the ordering provider, and flags the lab prints next to a result; those vary by lab, and the report's own key names each flag. MedlinePlus notes that "test results are measured with different units of measurement," that labs "often use different testing methods," and that "You can't compare test results from different labs." This page does not explain what a result means. As MedlinePlus puts it, "it's still important to talk with your provider to find out what your results really mean for you." Ask your clinician or the lab.

Sources: MedlinePlus, "How to Understand Your Lab Results," https://medlineplus.gov/lab-tests/how-to-understand-your-lab-results/ (accessed Oct 19, 2026). 42 CFR 493.1291, eCFR (accessed Oct 19, 2026).

Sections on the report

The list below is a document layout. Patient information, lab information, the report date, test name, result, units, and specimen notes follow 42 CFR 493.1291(c). The reference interval relates to 493.1291(d), which requires the lab's reference intervals to be available to the person who ordered the test; it does not require them to be printed on the report. Collection date, ordering provider, and flags are not in that rule. They may also show, and they vary by lab.

• Patient information: name or other identifier, ID number.
• Lab information: name and address of the lab that ran the test.
• Dates: report date (required). Collection date may also appear.
• Ordering provider (may appear).
• Test name, as the lab prints it.
• Result, as printed.
• Units, as printed.
• Reference interval, as printed by the lab.
• Flags: a letter or symbol the lab may print next to a result. The lab's own key on the report says what it stands for.
• Specimen notes, e.g. specimen source, or a note that a specimen didn't meet the lab's criteria.