Emergency room visit spanning midnight

A Medicare patient was taken to the ED on 10/20/14 and ended up being in the ED past midnight. His diagnosis was AMS (780.97). On 10/21/14, while still in the ED, a spinal tap (CPT® 62270) was done. The E/M (99285) was billed for on the DOS of 10/20/14 with Modifier -25, the tap was billed for on the DOS of 10/21/15. Is the Modifier -25 necessary as they are different dates of service?