Here's the MS bulletin page for MS17-010:
https://technet.microsoft.com/en-us/library/security/ms17-010.aspx
Which does indeed point you to KB4013380:
https://support.microsoft.com/en-us/help/4013389/title
However, that article in turn lists several other KB articles covering various products effected or patches addressing this vulnerability:
4012598 MS17-010: Description of the security update for Windows SMB Server: March 14, 2017
4012216 March 2017 Security Monthly Quality Rollup for Windows 8.1 and Windows Server 2012 R2
4012213 March 2017 Security Only Quality Update for Windows 8.1 and Windows Server 2012 R2
4012217 March 2017 Security Monthly Quality Rollup for Windows Server 2012
4012214 March 2017 Security Only Quality Update for Windows Server 2012
4012215 March 2017 Security Monthly Quality Rollup for Windows 7 SP1 and Windows Server 2008 R2 SP1
4012212 March 2017 Security Only Quality Update for Windows 7 SP1 and Windows Server 2008 R2 SP1
4013429 March 13, 2017—KB4013429 (OS Build 933)
4012606 March 14, 2017—KB4012606 (OS Build 17312)
4013198 March 14, 2017—KB4013198 (OS Build 830)
Any one or several of those may show up for you in WSUS, depending on which products are found in your environment.
In my own systems, that means I need to check for both 4012215 and 4012212. However, I don't have to manage any Windows 8 or Server 2012 machines. If those operating systems matter to you, the list is a bit longer.
Additionally, the monthly quality rollups really are rollups. I have machines that failed the March update, but succeeded in April or May. These machines still show "Failed" when I look at the WSUS reports for these KB#'s, but they're okay because they have the later updates.