Date format of CMS 1500

Providers and suppliers must report 8-digit dates in all date of birth fields (items 3, 9b, and 11a), and either 6-digit or 8-digit dates in all other date fields (items 11b, 12, 14, 16, 18, 19, 24a, and 31).


Providers and suppliers have the option of entering either a 6 or 8-digit date in items 11b, 14, 16, 18, 19, or 24a. However, if a provider of service or supplier chooses to enter 8-digit dates for items 11b, 14, 16, 18, 19, or 24a, he or she must enter 8-digit dates for all these fields. For instance, a provider of service or supplier will not be permitted to enter 8-digit dates for items 11b, 14, 16, 18, 19 and a 6-digit date for item 24a. The same applies to providers of service and suppliers who choose to submit 6-digit dates too. Items 12 and 31 are exempt from this requirement.

Legend                                    Description
MM                                    Month (e.g., December = 12)
DD                                        Day (e.g., Dec15 = 15)
YY                                  2 position Year (e.g., 1998 = 98)
CCYY                            4 position Year (e.g., 1998 = 1998)

(MM | DD | YY) or (MM | DD | CCYY)        A space must be reported between month, day, and year (e.g., 12 | 15 | 98 or 12 | 15 | 1998). This space is delineated by a dotted vertical line on the Form CMS-1500)

(MMDDYY) or (MMDDCCYY)                     No space must be reported between month, day, and year (e.g., 121598 or 12151998). The date must be recorded as one continuous number.