Box 18: Hospitalization dates
By Dr. Daniel Turner, DC · Reviewed September 2, 2026
What goes in Box 18 of the CMS-1500?
Admission and discharge dates when the services relate to a hospital stay. Almost always empty on chiropractic claims.
What does Box 18 mean for chiropractic billing?
Empty is the answer in nearly every chiropractic scenario. Its presence on the form is a reminder that the CMS-1500 serves all of outpatient medicine, not that your claims need it.
The mistakes that turn this box into denials
- ✗Filling it for patients who happen to have been hospitalized for something unrelated
How Cervica fills Box 18
Cervica generates the CMS-1500 and its electronic 837P equivalent from the chart and the payer's own rules: identifiers from the verified insurance record, modifiers and codes per payer, and pre submission scrubbing that flags exactly the mistakes listed above before a claim leaves the building.
Related boxes
- →Box 19 · Additional claim information
General information for billing teams, not billing advice for any individual claim. The NUCC's 1500 Claim Form instructions and each payer's companion guides control.