I need to complete Form 5307 to be filed with a Volume Submitter plan document. My question concerns line 3c, where the number of amendments is indicated for the submission. Since there were required amendments after the execution of the plan (e.g. EGTRRA, 401(a)(9), etc.), I would imagine I need to total these amendments, plus any other discretionary amendments and put this amount into 3c?

Now, if I was preparing a submission for a Standardized Adoption Agreement and if the regulatory amendments were prepared on a Sponsor Level, would I still be including these amendments in the line 3c?

Is an amendment an "amendment" for 5307 purposes regardless if Sponsor or Employer level? I appreciate any thoughts on this.

You said it right: an amendment is an amendment, whether generated by the sponsor or the employer.