Enrollments made through the mail are considered filed when deposited in the U.S. mail, if this is advantageous to the enrollee (i.e., when this allows the individual to be enrolled during a certain month but the actual date of receipt would not).

The date of deposit will ordinarily be the postmark date. However, a filing date may be established up to 2 days earlier than the postmark where there is an identifiable delay in handling of mail in the United States Postal Service. Verification of such delay from postal authorities is not normally needed.

A filing date earlier than 2 days prior to postmark may be established based on a credible statement from the enrollee which is not contradicted by other evidence (e.g., a date shown on the enrollment request agrees with or precedes the alleged date of deposit).

When enrollments are received through the mails early in the month following the end of the IEP or GEP, the envelope containing the postmark will be retained until the enrollment is finally processed.

Enrollments mailed to SSA may have a 7-day tolerance applied to them if the date of filing is material, the postmark is illegible or missing (or the envelope is missing or destroyed), and it originated in the continental United States (other than Alaska).

That is, if an enrollment is received during the first 7 days of the month following the end of an enrollment period (or month - where the month of enrollment is significant), it will be presumed, in the absence of any evidence to the contrary, that the enrollment request was mailed before the end of the enrollment period (or month).

Where the postmark is illegible or missing, and the enrollment request originated in Alaska, Hawaii, Puerto Rico, the Virgin Islands, Guam, American Samoa, or the Northern Mariana Islands, the mailing date is determined on a case-by-case basis.

Despite the above provisions, if the enrollment request is itself dated after the end of the enrollment period (or month, where the month of enrollment is significant), the writing would not be considered filed in the enrollment period (or month).