Introduction to cms

Vigneshwar Subramanian & Raoul R. Wadhwa

20 May 2020

The cms package implements a set of tools to download and clean publically available Medicare data, published on https://www.cms.gov, for analysis in R. This vignette provides an overview of the key features of the package.

Medicare Physician Fee Schedule (MPFS)

The get_mpfs function returns national payment files for the Medicare Physician Fee Schedule (MPFS). All revisions for a specified year between 2014 and 2020, inclusive (specified as 2-digit integer, 14 through 20) are downloaded from the CMS website to a user-specified path.

# Example, code not run within vignette itself. 
# Result is hardcoded and displayed for illustrative purposes.

library(cms)

# download and view first few rows of 2020 MPFS database
mpfs20 <- get_mpfs(20, storage_path = 'storage', keep_downloads = TRUE)
head(mpfs20, 3)
#>   Year Carrier Number Locality HCPCS Code Modifier PCTC Indicator Status Code
#> 1 2020          01112       05      G0076     none              0           A
#> 2 2020          01112       06      G0076     none              0           A
#> 3 2020          01112       07      G0076     none              0           A
#>   Multiple Surgery Indicator 50% Therapy Reduction Amount (non-institutional)
#> 1                          0                                       0000000.00
#> 2                          0                                       0000000.00
#> 3                          0                                       0000000.00
#>   50% Therapy Reduction Amount (institutional) OPPS Indicator Facility Fee
#> 1                                   0000000.00              9        63.64
#> 2                                   0000000.00              9        63.64
#> 3                                   0000000.00              9        63.64
#>   Non-Facility Fee OPPS Facility Fee OPPS Non-Facility Fee
#> 1            63.64                 0                     0
#> 2            63.64                 0                     0
#> 3            63.64                 0                     0

By default, get_mpfs will store downloaded .zip files so that subsequent calls to get_mpfs with the same year and storage path will not require redownloading the raw data to import the database. get_mpfs will instead delete downloaded files by passing the argument keep_downloads = FALSE.

Optionally, users can specify a valid 7-digit locality code (5-digit carrier number + 2-digit locality, passed as a single string) to instruct get_mpfs to return only the data corresponding to that locality:

# Example, code not run within vignette itself. 
# Result is hardcoded and displayed for illustrative purposes.

mpfs20_ohio <- get_mpfs(20, storage_path = 'storage', locality = '1520200')
head(mpfs20_ohio, 3)
#>   Year Carrier Number Locality HCPCS Code Modifier PCTC Indicator Status Code
#> 1 2020          15202       00      G0076     none              0           A
#> 2 2020          15202       00      G0077     none              0           A
#> 3 2020          15202       00      G0078     none              0           A
#>   Multiple Surgery Indicator 50% Therapy Reduction Amount (non-institutional)
#> 1                          0                                       0000000.00
#> 2                          0                                       0000000.00
#> 3                          0                                       0000000.00
#>   50% Therapy Reduction Amount (institutional) OPPS Indicator Facility Fee
#> 1                                   0000000.00              9        55.71
#> 2                                   0000000.00              9        79.54
#> 3                                   0000000.00              9       131.29
#>   Non-Facility Fee OPPS Facility Fee OPPS Non-Facility Fee
#> 1            55.71                 0                     0
#> 2            79.54                 0                     0
#> 3           131.29                 0                     0

Medicare Locality Key

The locality_dict dataset contains the locality definitions used by the MPFS, updated for 2020.

mpfs20_locality <- cms::locality_dict
head(mpfs20_locality, 3)
#>   Carrier Number Locality   State Fee Schedule Area     Counties
#> 1          10102       00 ALABAMA         STATEWIDE ALL COUNTIES
#> 2          02102       01  ALASKA         STATEWIDE ALL COUNTIES
#> 3          03102       00 ARIZONA         STATEWIDE ALL COUNTIES