The sprain and strain codes offer three choices for the final character:

• A - initial encounter
• D - subsequent encounter
• S - sequela

The "A" and the "D" might be used by payers three ways:

1. The "A" for "initial encounter" applies only to the first visit, and the "D" for "subsequent encounter" is used for all visits that follow.
2. The "A" is used for the first few weeks, while the patient receives passive modalities, then the "D" is used when rehab/exercises begin.
3. The "A" is used for all treatments during the course of care, and the "D" would be applied if the patient switched to "maintenance care".

At this time, it is believed that the third scenario is most likely because the guidelines define "A -Initial encounter" as care that is considered "active treatment", which is similar to the AT modifier requirement for procedure codes.  And the "D - subsequent encounter" is defined as "aftercare" or "follow-up" which is similar to the definition for "maintenance care".  While some providers view the word "encounter" to mean "visit", it may help to replace the word "encounter" with "phase of care".

Furthermore, the most recent draft of nearly every Medicare contractor LCD (Local Coverage Determination) available lists the codes that might be acceptable to Medicare, and none of them end with the "D", implying that it is probably not payable.  In other words, if you had to start using these codes today, ChiroCode would recommend that you bill with the "A" for all visits expect to be deemed "medically necessary", and never use the "D" when billing a third party.  But, please keep in mind that this is just an educated guess and is subject to change as more information becomes available. 

If you have more questions, consider using the ChiroCode HelpDesk through your membership.