Vintage (RIN vintage year)

The vintage of a Renewable Identification Number (RIN) under the U.S. Renewable Fuel Standard (RFS) is the calendar year of generation embedded in the 38-character RIN identifier specified at 40 CFR 80.1426(f)(3). The vintage year governs how long the RIN remains valid for compliance and how it interacts with deficit carry-forward, prior-year rollover caps, and the annual Renewable Volume Obligation.

Two-year vintage window

A RIN is valid for the calendar year of generation and the immediately following compliance year, with restrictions, under 40 CFR 80.1427. A 2025-vintage D4 RIN can be retired against either the 2025 or 2026 compliance-year obligation; after 2026 it expires. The two-year window applies across all four D-codes (D3, D4, D5, D6).

20% rollover cap

Under 40 CFR 80.1427(a)(5), the use of prior-vintage RINs against the current-year RVO is capped at 20% of that RVO. In practice this means that no more than 20% of an obligated party's 2026 retirements can be 2025-vintage RINs — at least 80% must be 2026-vintage. The cap applies separately to each of the four sub-obligations (cellulosic, biomass- based diesel, advanced, total renewable). The cap is intended to prevent excessive RIN inventory build that could distort the program's year-over-year volume signal.

Deficit carry-forward

Separately from rollover, 40 CFR 80.1427(b) allows an obligated party to carry up to a one-year deficit forward, provided the deficit is fully made up in the next compliance year using current-year RINs. Repeated deficit carry-forwards are not permitted. The deficit-carry-forward mechanism is operationally distinct from the 20% rollover cap; the two provisions can interact, but each operates against a different compliance-year boundary.

Vintage in EMTS records

The EPA Moderated Transaction System (EMTS) records the vintage as a field on every RIN transaction event — generation, transfer, separation, retirement. Obligated parties' compliance-team workflows typically include reconciling current-vintage and prior-vintage holdings before the 31 March compliance deadline at 40 CFR 80.1451 to confirm that no more than 20% of the year's retirement plan relies on prior-vintage RINs.

Public aggregates and vintage

The weekly RIN Trades and Price Information page published by EPA aggregates trades by D-code and reports a single weekly volume-weighted average price per category. Vintage breakdowns are reported in EPA's quarterly Public Data on RIN Generation, Transactions and Volumes and in the annual EMTS public aggregates, but the headline weekly price is not vintage-disaggregated. Charts that report the headline series are therefore an aggregate across in-window vintages.

Historical context

The vintage framework is unchanged since the 2010 RFS2 final rule (75 FR 14670, 26 March 2010). EPA has clarified the operational mechanics in subsequent annual and multi-year rulemakings, but the two-year window and 20% rollover cap have remained the structural backbone of the program's vintage discipline. The 2027 equivalence-value regime change does not affect vintage rules — it changes the EV multiplier embedded in the RIN at generation time, not the vintage validity window.

Common compliance-team patterns

Three common patterns shape how obligated-party compliance teams manage vintage:

1. Year-end inventory check. In the fourth quarter, the team reconciles current-vintage and prior-vintage holdings against the year's RVO. The 20% rollover cap is applied separately to each sub-obligation.
2. First-quarter true-up. Before the 31 March compliance deadline, the team allocates any prior-vintage RINs that remain usable against the just-closed compliance year, then files via EMTS.
3. Vintage-aware procurement. Prior-vintage RINs typically trade at a small discount to current-vintage RINs because of the validity horizon and the 20% cap. Programmatic procurement teams account for this in scenario planning.

Sources

EPA RFS regulations: 40 CFR 80.1426(f)(3) (RIN structure), 40 CFR 80.1427 (vintage validity, rollover cap, deficit carry-forward), 40 CFR 80.1451 (annual compliance demonstration). The 2010 RFS2 final rule is at 75 FR 14670. Quarterly public aggregates are on the EPA "Public Data for the Renewable Fuel Standard" page.