In Block 13, Medicare requires either an 8-digit MMDDCCYY or 6-digit MMDDYY date. Which of the following options correctly states this date format?

• A. A 4-digit year only.
• B. An 8-digit MMDDCCYY or 6-digit MMDDYY date.
• C. Only MMDDYY.
• D. Only CCYYMMDD format.

Answer: (B)

Dates in Block 13 must be entered in a numeric month-day-year format, with the month first, then the day, then the year. Medicare accepts two possibilities: an eight-digit form using the full year (MMDDCCYY) or a six-digit form using a two-digit year (MMDDYY). Using one of these two formats avoids ambiguity and ensures the payer’s system reads the date correctly.

Other formats don’t fit because they either omit part of the date (such as just the year), change the order (like CCYYMMDD), or restrict you to a single form when Medicare explicitly accepts both eight-digit and six-digit versions.