We have had a few customers and partners notice when using Dynamics GP 2013,  they do not have the Inventory module option available when navigating to Microsoft Dynamics GP> Tools> Routines> Financial> Reconcile to GL

On Dynamics GP 2010, the modules available to reconcile are: Payables Management and Receivables Management. However, on Dynamics GP 2013, Bank Reconciliation and Inventory were added to the list of modules.

If you are registered for Inventory Control and do not have Inventory available from the Reconcile to GL window, it is likely because HITB (Historical Inventory Trial Balance) is not enabled. You can verify this by navigating to Reports> Inventory> Activity. Check if Historical IV Trial Balance is an available report. If not, you will need to enable HITB to be able to reconcile Inventory to the GL using this new feature in Dynamics GP 2013 which was designed to help users analyze differences between the Historical Inventory Trial balance report and the associated inventory accounts in the GL.

Here is a link to more information on enabling the HITB report:

Historical Inventory Trial Balance Inventory Reset Tool for Microsoft Dynamics GP

https://mbs.microsoft.com/partnersource/downloads/releases/mdgp10_hitb.htm?printpage=false&sid=heqrux3qy5jdaxmzeb31aqii&stext=hitb