This is a CCW-derived field that indicates the cost-sharing tier in which the prescription was placed, according to the benefit structure and formulary for the beneficiary’s plan. If a product is part of two different tiers, this field is populated with the minimum tier value for the product.
Starting in 2010, this variable is included in the Formulary file (rather than the PDE file).
Part D plan sponsors submit the pricing, tiers, and formularies for their plan benefit packages to CMS via the Health Plan Management System (HPMS).
This includes information on how many cost-sharing tiers each plan will use and the drugs that will be on each tier. The CCW creates this variable based on the beneficiary’s plan of record, which is identified using the Part D contract and plan benefit package of record (the PLAN_CNTRCT_REC_ID and PLAN_PBP_REC_ID variables). For a small number of beneficiaries, particularly those who changed plans around the time of the fill, the variable may not be an accurate reflection of whether the PDE was on a particular drug tier.
Source: PDE and Plan Characteristics (derived)
1-6 = The tier on the plan's formulary associated with the drug on the PDE
(Note: if the plan is not required to submit a formulary then TIER_ID is assigned a value of '1')