X12 837P DTP01 (Date/Time Qualifier): Format, Values, and Testing Notes
Every DTP segment on a claim looks the same at a glance — three elements, a code, a value. DTP01 is the only thing that tells you what you're actually looking at, and a parser that skims past it will happily file an admission date under statement dates.
DTP01 is the Date/Time Qualifier in an X12 837P claim — a code that identifies which specific date or date period the DTP segment is reporting, since the same segment structure is reused for onset dates, statement periods, admission and discharge dates, and several others.
Common code values
Example
DTP01 value 434 marks this as the statement dates period, paired with a date range in DTP03. Synthetic claim data.
Where this trips people up
Fixture data tends to include just enough DTP segments to make one claim scenario pass — usually 431 for a professional claim and maybe 434 if the test happens to touch statement dates. Qualifiers like 096 and 435 rarely show up until an institutional-adjacent scenario forces the issue, so a mapping table built from early test files quietly has no case for them and either drops the segment or throws it into a catch-all bucket the first time production sends one.