CMS Public Use Files (PUF)

Path B data source — 21+DC state-based marketplace states

Overview

CMS publishes standardized Public Use Files containing all plan data for every state-based exchange (SBE). Combined with the federal APTC formula, these enable subsidized premium calculations identical to what each state's marketplace shows consumers.

Source: https://www.cms.gov/marketplace/resources/data/state-based-public-use-filesFormat: ZIP containing 6 CSVs per state Refresh: Annually (typically Q4 before open enrollment)

Files Per State

File	Records (est.)	Key Fields	Critical?
Rate PUF	~50K/state	plan_id, age, rating_area, premium	YES
Plan Attributes PUF	~300/state	plan_id, metal_level, deductibles, CSR variants	YES
Benefits PUF	~3K/state	plan_id, benefit_name, is_covered	Partial
Service Area PUF	~500/state	issuer, county, zips, rating_area	YES
Network PUF	~100/state	plan_id, network_url	Nice to have
Business Rules PUF	~50/state	rating methodology	Low priority

States Covered

CA, CO, CT, DC, GA, ID, IL, KY, ME, MD, MA, MN, NV, NJ, NM, NY, PA, RI, VT, VA, WA

Schema Notes

• CSR variants use plan ID suffixes: -01 (standard), -02 (zero cost), -03 (limited), -04 (73% AV), -05 (87% AV), -06 (94% AV)
• Rating areas are state-defined geographic regions. Mapping from zip → rating area requires parsing the Service Area PUF.
• Benefits PUF has coverage flags but NOT copay dollar amounts. Copay data comes from the Plan Attributes PUF SBC columns or requires SBC PDF parsing.
• Age-rated premiums in the Rate PUF are per-individual, per-age (0-64), per-plan, per-rating-area. Household premium = sum of individual premiums for each member.

Validated Against

• Covered California 2026 website — 10 scenarios, 4/6 marketplace scenarios within $0.44-$8.29
• See validation docs for full results