Is the new lateral promotion from SPC to CPL automatic or would the SM have to wait for a 4187 to be approved?

4187 is still required.

As I have stated several time and will continue to believe, the Army made a great mistake when they got rid of the SPC ranks. Not everyone is a leader, and not everyone can be made a leader. There are those who are very proficient at their MOS but they are not leaders. There needs to remain a way for these soldiers to move up not out. Once the Army again realizes this fact, things will be much better off.

4187 is required. The SM gets promoted to SPC and remains as a SPC until they go before the board and BLC, then they become (P) and their command should submit a 4187 for a lateral transfer to CPL.

In my experience it was usually conferred to a SPC/4 who had been to or was awaiting the E-5 board and was already in a leadership slot or performing the duties of a Sergeant.

DA 4187 for Lateral Appointment to Corporal must be submitted through your BN S1 prior to pinning rank. The 4187 must be accompanied with your SRB and BLC Certificate. Reason for SRB is to show that you are indeed promotable since some folks have gone through BLC with out having been to the promotion board. Directive 2021-17 states that Specialists must go through promotion board and BLC in order to be laterally promoted to Corporal. S1 will update eMilpo to show your new rank. Date of rank does not change from when you made Specialist since it is the same pay grade. I hope this helps.

Good question.

Since the Big Army has decreed it, much like an automatic promotion, I don't think it needs a whole ceremony for a rank no one wants. Just like any rank, I think you should just be able to put it on once it's on your srb. Command teams tell soldiers that they have to be pinned before they can wear it, but that's not what regs say. They just want to feel good about themselves.

I understood it to mean automatic. The regulation didn't say will be promoted to. It said you are now this rank.