Pulling values from one table in an app to a field in another table

I need to pull a value from a supporting table in the app (Dental cost) to a field (Coverage Tier) in another table based upon selection of coverage tier.  Essentially, I have some data tables that have dental coverage tier and an associated cost of each tier.

So, if I choose Employee Only (Coverage Tier) in the main table, I need it to look to the "Dental Table" and pull the coverage cost value matching the Employee Only (Coverage Tier).  The coverage tier language match in the main table and the supporting table.  There are five tiers (Employee Only, Employee + Spouse, Employee + Children, Family, and Waived).

I would like to be able to pull the valued directly from the Dental Table so when the values change annually, I can just make the adjustment in one place and all the associated employee's record in the Main Table will adjust accordingly.

Thanks in advance!!!