D5 RIN

A D5 RIN is the Renewable Identification Number assigned to a gallon of advanced biofuel that is neither cellulosic nor biomass-based diesel under the U.S. Renewable Fuel Standard (RFS). The D5 category sits in the middle of the program's nesting hierarchy: it is more general than D3 or D4 but more specific than the conventional D6 pool. Because of this position, D5 RINs are commonly described as the "advanced non-BBD" tier.

Pathways approved as D5

EPA's pathway determinations under 40 CFR 80.1426 govern which fuel/ feedstock combinations may generate D5 RINs. Approved D5 pathways have historically included sugarcane ethanol imported from Brazil, biogas/ naphtha pathways from biomass that do not qualify as cellulosic, butanol from advanced biomass feedstocks, and certain renewable gasoline streams derived from biomass. The full list is published in EPA's Approved Pathways for Renewable Fuel and is updated as new petitions clear the 40 CFR 80.1416 review process.

The advanced-biofuel definition under section 211(o)(1)(B) of the Clean Air Act requires a 50% lifecycle greenhouse-gas reduction relative to the 2005 petroleum baseline. Pathways that are derived from corn starch do not qualify as advanced unless they meet additional criteria (combined heat and power configuration, qualifying feedstock blend) set out in the original RFS2 rulemaking (75 FR 14670, 26 March 2010) and subsequent pathway petitions.

Equivalence values for D5 fuels

A D5 RIN is one ethanol-equivalent gallon. Like other D-codes, the ethanol-equivalent yield per physical gallon depends on the fuel and is set by 40 CFR 80.1415:

• Ethanol pathways (sugarcane, advanced corn-starch with qualifying CHP configurations) — 1.0 RINs per gallon
• Renewable gasoline and renewable gasoline blendstocks — 1.0 RINs per gallon (energy parity with conventional gasoline)
• Other ethanol-equivalent fuels — pathway-specific multipliers as listed in the rulemaking

The 2027 EV regime change — which moves non-ester EVs to a flat 1.5 — is written for biomass-based diesel and renewable diesel and does not change the D5 ethanol multipliers.

Use of D5 RINs in compliance

The nesting rule under 40 CFR 80.1427 allows D5 RINs to satisfy the D5 RVO or to be used downward against the D6 conventional RVO. They cannot satisfy a D4 (biomass-based diesel) or D3 (cellulosic) obligation. In practice, when the cellulosic D3 supply has fallen short of the cellulosic RVO, EPA has issued cellulosic waiver credits at a regulatory price; obligated parties have alternately retired D5 RINs upward to satisfy the advanced-biofuel sub-obligation that nests above D6.

Vintage and carryover

Like other D-codes, D5 RINs carry a vintage year embedded in the 38-character RIN identifier. RINs are valid for the calendar year of generation and the following compliance year, with a 20% rollover cap on prior-vintage RINs against current-year obligations under 40 CFR 80.1427. Two-year vintage windows mean a 2025-vintage D5 RIN is usable for 2025 or 2026 compliance and is then expired.

Historical context

The D5 pool has historically been smaller than D4 or D6, with sugarcane ethanol imports the dominant source through the late 2010s. Imports contracted after 2020 as Brazilian domestic demand rose and as the peso/real exchange rate moved. The 2023 multi-year Set Rule (88 FR 44468, 27 July 2023) set the advanced-biofuel RVO above the cellulosic RVO, preserving a structural D5 sub-obligation. Public EMTS aggregates show the D5 weekly volume-weighted average price has historically tracked between the D4 and D6 prices, reflecting the nesting position.

Sources

EPA RFS regulations: 40 CFR 80.1415 (EVs), 40 CFR 80.1426 (RIN generation), 40 CFR 80.1416 (pathway petition process), 40 CFR 80.1427 (nesting and obligation discharge). Approved Pathways for Renewable Fuel is maintained on the EPA RFS website. Aggregated weekly D5 RIN data appear on the EPA "RIN Trades and Price Information" page.