Access county-level data on NFIP policies — get_nfip

Retrieves National Flood Insurance Program (NFIP) policy data at the county level, including both current and historical policies.

Usage

get_nfip_policies(
  state_abbreviation,
  county_geoids = NULL,
  file_name = NULL,
  api = FALSE
)

Arguments

state_abbreviation: A 2 letter state abbreviation (e.g. TX).
county_geoids: A character vector of five-digit county codes.
file_name: The name (not the full path) of a per-state Box file containing the raw data (see @details). If NULL (default), reads state_abbreviation's records directly from the most recently cached nationwide file for this dataset (see get_openfema_cache_path()), which avoids the cross-border duplication issue described below entirely.
api: If TRUE, query the API. If FALSE (default), read from file_name.

Value

A dataframe of project-level funding requests and awards, along with variables that can be aggregated to the county level.

id: Unique identifier for the policy record; use this to de-duplicate cross-border policies after combining results from multiple states – see @details.
state_fips: A two-digit state identifier.
state_abbreviation: The two-character abbreviation of the state.
county_code: The five-digit county identifier.
county_name: The name of the county.
census_tract: The 11-digit census tract code.
policy_cost: The cost of the policy summing the calculated premium, reserve fund assessment, federal policy fee, and HFIAA surcharge.
policy_count: The number of insured units in active status associated with the policy.
policy_rated_flood_zone: The NFIP flood zone.
policy_premium_total_cost: The policy premium; negative values indicate a refund.
policy_date_termination: The date when the policy is no longer in effect, either because it was cancelled or lapsed.
policy_date_effective: The effective date of the flood policy.
building_occupancy_type: The occupancy type of the building.
building_replacement_cost: The insurer's estimated cost to replace the building.

Details

Data are from FEMA's OpenFEMA API. See https://www.fema.gov/openfema-data-page/fima-nfip-redacted-policies-v2.

The following dataset houses information on NFIP policies (both historic and current). In order to filter to current policies, the analyst will need to filter on the policy_date_termination and policy_date_effective columns.

The dataset also contains both residential and commercial policies. In order to filter to residential policies, the analyst can filter out the "non-residential" occupancy type.

When file_name is supplied explicitly, per-state files (in the intermediate/ Box folder) are not mutually exclusive: a policy whose county sits near a state border can appear in more than one state's file. When looping this function over multiple states this way and combining results, run dplyr::distinct(id, .keep_all = TRUE) on the combined data to remove these duplicates (verified: 72 Delaware-file rows keyed to Maryland counties, all also present in Maryland's own file). This does not apply to the default (cache-backed) mode, which reads directly from the single nationwide file.

Examples

if (FALSE) { # \dontrun{
 test <- get_nfip_policies(
      state_abbreviation = "TX",
      county_geoids = c("48201"),
      file_name = "fima_nfip_policies_2025_10_14.parquet",
      api = FALSE) |>
    dplyr::filter(
      !building_occupancy_type %in% c("non-residential"), ### only residential claims,
      policy_date_termination >= as.Date("2025-10-15"),
      policy_date_effective <= as.Date("2025-10-15")) |>
    dplyr::group_by(county_geoid)|>
    dplyr::summarise(avg_policy_cost = mean(policy_cost))
} # }