NCH Claim Payment Amount to Beneficiary
The total payments made to the beneficiary for this claim (sum of all line-level payments to beneficiary, variable called LINE_BENE_PMT_AMT)
This variable is populated if, for example, a beneficiary pays for a service that should have been Medicare-covered.
The beneficiary can be refunded the payment.
Costs to that beneficiaries are liable for are described in detail on the Medicare.gov website. There is a CMS publication called "Your Medicare Benefits", which explains the deductibles and coinsurance amounts.
Medicare payments are described in detail in a series of Medicare Payment Advisory Commission (MedPAC) documents called "Payment Basics" (see: http://www.medpac.gov/payment_basics.cfm).
Also in the Medicare Learning Network (MLN) "Payment System Fact Sheet Series" (see the list of MLN publications at: http://www.cms.gov/Outreach-and-ducation/Medicare-Learning-Network-MLN/MLNProducts/MLN-Publications.html)
Some additional information on this variable: