What Are RINs? D4 vs D6 RIN Prices Explained

A RIN (Renewable Identification Number) is the credit EPA tracks for each ethanol-equivalent gallon of renewable fuel, and refiners and importers must retire RINs in proportion to the gasoline and diesel they sell. D6 RINs come mainly from corn ethanol and D4 RINs from biodiesel and renewable diesel. Because a D4 can stand in for a D6, the D6 price averaged at or below D4 in every year from 2015 to 2025: in 2025, $0.91 against $0.95, by EPA’s trade data.

The US generated 14.67 billion D6 RINs and 7.13 billion D4 RINs in 2025. Priced at that year’s average trade values, the 2025 percentage standards cost about 13.23 cents for every gallon of petroleum gasoline or diesel a refiner produced or imported. The same obligation applies to a gallon of gasoline and a gallon of diesel; the difference shows up only once renewable fuel is blended in, because the blended share brings RINs back. E10 gasoline nets out at about 2.80 cents, while straight petroleum diesel carries the full amount. Two fuels set most of that supply: renewable diesel and biodiesel on the D4 side, and ethanol, whose blend limit is the subject of how E15 differs from regular 87.

A credit made of data fields, not a barcode

The Renewable Fuel Standard, created by the Energy Policy Act of 2005 and expanded by the Energy Independence and Security Act of 2007, requires a minimum volume of renewable fuel in US transportation fuel. EPA does not track the fuel molecule by molecule. It tracks credits. When a producer or importer makes a batch of qualifying fuel, it generates RINs for that batch in EMTS, the EPA Moderated Transaction System, which has held RIN data since July 1, 2010.

The 38-digit code quoted in older descriptions of RINs is real but obsolete: 40 CFR 80.1425 says RINs generated on or after July 1, 2010 are not generated as a 38-digit code and are instead identified by data elements entered in EMTS. The elements carried over from the old code are the useful part. They record the year of generation, the registration number of the producer or importer, the facility, a batch serial number, a two-digit field equal to ten times the equivalence value, and the D-code that identifies the fuel category. The old code also had a K digit marking whether the RIN was still attached to fuel or had been separated from it, and that distinction still drives the market.

A RIN starts life assigned to its batch. It travels with the fuel from party to party until an obligated party (a refiner or importer of gasoline or diesel) buys the fuel or until the fuel is blended into gasoline or diesel. At that point the RIN is separated. A separated RIN can be bought and sold on its own until someone retires it against a compliance obligation. The prices EPA publishes are prices of separated RINs, which is why they behave like any other traded credit.

Equivalence values exist because the program counts in ethanol-equivalent gallons. A gallon of renewable diesel carries more energy than a gallon of ethanol, so it earns more credits. That is the first reason a D4 RIN count runs well ahead of the physical gallons behind it: EMTS shows 7.13 billion D4 RINs in 2025 from 4.36 billion gallons, an implied average of 1.64 RINs per gallon. In 2015 the same ratio was 1.53. The fuel mix explains the rise. By EMTS fuel category, biodiesel generated 81 percent of D4 RINs in 2015 and non-ester renewable diesel 19 percent; in 2025 renewable diesel generated 70 percent, biodiesel 24 percent and renewable jet fuel 6.5 percent.

D3 to D7: what each code certifies and which obligation it fills

The D-code reflects the fuel’s category, set by its feedstock, process and lifecycle greenhouse gas reduction against a 2005 petroleum baseline. EPA lists the thresholds on its program overview: 20 percent for conventional renewable fuel, 50 percent for advanced biofuel and biomass-based diesel, and 60 percent for cellulosic biofuel. Facilities producing before the 2007 law are grandfathered for their baseline volumes.

Each obligated party has four obligations, one per category, called Renewable Volume Obligations (RVOs). The obligation for each is the percentage standard multiplied by the non-renewable gasoline and diesel the party produced or imported that year, under 40 CFR 80.1407. The four are nested: the cellulosic and biomass-based diesel obligations sit inside the advanced obligation, which sits inside the total. And 80.1427(a)(3)(i) lets the same RIN count toward more than one obligation if it is valid for each. A single D4 RIN therefore retires a gallon of biomass-based diesel obligation, a gallon of advanced obligation and a gallon of total obligation at once. That one sentence of regulation explains most of how RIN prices relate to each other.

Eleven years of RIN generation, by D-code

Conventional generation has been flat for a decade. D6 output stayed between 14.26 and 15.18 billion RINs in every year shown except 2020, when it fell to 12.99 billion as fuel demand dropped. Almost all of it is corn ethanol at one RIN per gallon, and gasoline blended at 10 percent ethanol has a ceiling on how much ethanol it can absorb, a limit the E15 guide covers in detail.

Biomass-based diesel is where the growth came from. D4 generation rose from 2.80 billion RINs in 2015 to 9.18 billion in 2024, 3.3 times as many, then fell 22 percent to 7.13 billion in 2025. Cellulosic RINs grew 9.1-fold over the period, from 142 million to 1,291 million; in 2025, 93 percent of D3 RINs came from renewable natural gas, by EMTS fuel category. D5 stayed small, between 98 and 343 million a year, and D7 never reached three million.

The volumes matter for prices because of a number EPA itself uses: the implied conventional volume, the total renewable fuel requirement minus the advanced requirement. EPA’s April 2026 rule says it kept the 15-billion-gallon implied conventional volume set for 2023 to 2025 and implied in the statutory volumes for 2015 to 2022. D6 generation in 2023, 2024 and 2025 came in at 14.84, 14.91 and 14.67 billion, just under that line. Any shortfall has to be covered by a RIN from a higher category, and the cheapest higher category with real volume is D4.

EPA’s RIN price record, 2015 to 2025

EPA publishes weekly volume-weighted average prices for separated RINs by transfer date, from standard trades reported in EMTS. The annual figures below re-weight those weekly averages by the RINs traded in each week, so a week with 500 million RINs counts five times as much as a week with 100 million.

Traded volume exceeds generation in most years because a separated RIN can change hands more than once before it is retired: 25,920 million D6 RINs traded in 2025, against 14,666 million generated.

The record has three phases. From 2015 to 2017, D4 traded between $0.73 and $1.02 and D6 between $0.56 and $0.77. From 2018 to 2020, both fell, and D6 bottomed at $0.17 in 2019. From 2021 to 2023, both rose above a dollar, with D4 peaking at $1.61 in 2022 and D6 at $1.45 in 2023. In 2024, the year D4 generation set its record, the D4 price halved to $0.76; it recovered to $0.95 in 2025, when generation fell back. D3 is in a separate band throughout, from $0.91 in 2015 to $3.11 in 2024.

Reading EPA’s RIN dashboards yourself

Every figure in Tables 3 and 4 can be rebuilt from EPA’s public pages, which run on a Qlik Sense dashboard with an export button. A few settings decide whether a reader’s numbers will match.

• Transfer date versus RIN year. The price series is organized by the week the RIN changed hands. A 2024-vintage RIN sold in March 2025 counts in 2025 here. Filtering by RIN year instead gives a different average.
• Weekly averages are already weighted. Averaging the weekly prices without weights gives a different number from weighting by volume. For 2025 D6, a simple mean of the weekly rows would differ from the $0.91 volume-weighted figure by a cent or two.
• QAP type. Prices are split by whether a RIN was verified under a Quality Assurance Plan (Q-RINs) or not. Table 4 combines both.
• EPA’s outlier filters. Trades below $0.05 or above $3.00 ($3.50 for D3) are dropped from 2020 onward, and the pre-2020 D4, D5 and D6 caps were $2.00, so the dashboard never shows a price outside those bands.
• Revisions. EPA updates the data monthly and warns that remedial actions and resubmitted reports can change past figures.
• Generation versus net generation. The generation summary counts RINs as generated. EPA’s separate net generation view subtracts RINs later retired as invalid or as volume error corrections.

Generation itself depends on the physical fuel. The production capacity, trade and prices that decide how many D4 RINs get made are laid out in the renewable diesel and biodiesel comparison.

Why D6 cannot outrun D4

The nesting rule sets a price ordering. Any obligated party that needs a D6 RIN for its total renewable fuel obligation can retire a D4 RIN in its place, because 80.1427(a)(2)(iv) lists D3, D4, D5, D6 and D7 as valid for that obligation. If D6 ever traded above D4, buyers would switch. So the D4 price works as a ceiling on the D6 price. The reverse is not true: a D6 cannot fill a biomass-based diesel or advanced obligation, so D4 has no ceiling from D6, only a floor. In the full sequence, D6 at or below D5 at or below D4 is the expected order, with D3 apart because only D3 and D7 satisfy the cellulosic obligation.

How close D6 sits to the ceiling depends on whether D6 alone can cover the conventional slice. When ethanol RINs are plentiful relative to the requirement, D6 trades on its own supply and demand and can fall far below D4. When they run short, the marginal RIN for the conventional slice is a D4, and the D6 price is pulled up toward it. Exemptions shift the balance too, because a refinery granted a small refinery exemption has no obligation to cover for that year.

The narrowest spreads came in 2023, 2024 and 2025: $0.07, $0.05 and $0.04. In each of those years the implied conventional volume was 15.00 billion and D6 generation fell short of it, so D4 RINs or banked prior-year RINs had to fill part of the conventional slice and the D6 price converged on D4. The shortfall alone does not set the spread, since D6 generation also fell short in 2019 and 2022. The widest spreads, $0.31 in 2017 and $0.31 in 2019, fall in the 2017 to 2019 exemption peak: 17.05 billion gallons of gasoline and diesel exempted for 2017 and 12.00 billion for 2019, against 3.07 billion for 2015. Fewer obligated gallons meant fewer RINs needed, and D6 could fall away from the ceiling.

One caution on the exemption column. EPA’s table records the exemptions as finally decided, and many decisions came years after the compliance year; EPA acted on a backlog of petitions in 2025, according to its Set 2 fact sheet. The column shows how large the exemptions turned out to be, not when traders learned of them. Carryover RINs, the blend wall and diesel demand all move the spread as well. The table is consistent with the nesting logic; it does not isolate one cause.

From a credit price to cents per gallon

A refiner’s RIN bill per gallon of petroleum fuel follows directly from the percentage standards. Each percentage is the number of RINs owed per 100 gallons of non-renewable gasoline or diesel, so a percentage multiplied by a price in dollars gives cents per gallon. Because nested RINs count toward several obligations at once, the total number of RINs owed equals the total renewable fuel percentage, split into four slices.

1. Cellulosic slice: 0.71 RINs per 100 gallons at $2.50 = 1.78 cents per gallon.
2. Biomass-based diesel slice: 3.15 at $0.95 = 2.99 cents.
3. Advanced-only slice: 4.31 minus 3.15 minus 0.71 leaves 0.45, at $0.95 = 0.43 cents.
4. Conventional slice: 13.13 minus 4.31 leaves 8.82, at $0.91 = 8.03 cents.
5. Total: 1.78 + 2.99 + 0.43 + 8.03 = 13.23 cents per gallon of petroleum gasoline or diesel.

The conventional slice is 61 percent of the bill even though D6 is the cheapest RIN, because it is by far the largest slice. Running the same formula over every year gives the series below.

The bill ranged from 2.77 cents in 2019 to 18.30 cents in 2023, a factor of more than six, while the total standard moved only from 10.97 to 12.10 percent. Prices, not percentages, drove most of the swing.

The table is an approximation in three ways. It pairs each year’s standard with RINs traded in that calendar year, but compliance for year i can use RINs bought through the following year’s deadline. Up to 20 percent of each obligation can be met with prior-year RINs under 80.1427(a)(5), and those were bought at older prices. And many refiners generate their own RINs by blending, so their cash outlay differs from the market value of the obligation. The figures measure what the obligation was worth at market, which is the cost a refiner without blending capacity would face.

Same obligation, different blends: E10, B5 and B20

Gasoline and diesel carry the same percentage, so a gallon of petroleum gasoline and a gallon of petroleum diesel carry the same RIN cost. The difference appears in the finished fuel, because the renewable share is not obligated and brings separated RINs with it. For a gallon of E10, the obligation falls on the 0.9 gallon of petroleum blendstock, and the 0.1 gallon of ethanol releases 0.1 D6 RIN. For B20, the obligation falls on 0.8 gallon and the 0.2 gallon of biodiesel releases 0.3 D4 RIN, at the 1.5 equivalence value.

For 2025 that means about 2.80 cents for E10, 5.44 cents for B5 and a credit of 17.91 cents for B20, against 13.23 cents for unblended petroleum fuel. The E10 result is the arithmetic behind a statement in EPA’s April 2026 rule, which said higher D6 prices have little to no impact on E10, about 97 percent of the gasoline EPA projects for 2026 and 2027. Using the 2025 standards, a $1 rise in the D6 price adds 0.9 x 8.82 = 7.94 cents of obligation to an E10 gallon and 10 cents of RIN value, a net change of -2.06 cents. EPA describes the effect as a cross-subsidy: RINs raise the price of fuels with little or no renewable content and lower the price of high-renewable blends.

Diesel is where the cost is most visible: diesel sold with no biodiesel or renewable diesel blended in carries the full obligation and earns nothing back. The diesel price guide breaks down the other parts of the pump price, and the gasoline price breakdown shows where a refiner’s costs sit inside a gallon of regular. EPA states that, on average at the national scale, obligated parties that buy RINs recover their cost in the prices of the gasoline and diesel they sell. RIN costs therefore also show up in refining margins, the subject of the crack spread guide, since the futures used in a 3-2-1 crack price the fuel but not the refiner’s RIN obligation.

Banked RINs, carried deficits and the two-year clock

A RIN has a short shelf life. Under 40 CFR 80.1427(a)(6) it can be used only for the compliance year in which it was generated or the year after, and 80.1427(a)(5) caps prior-year RINs at 20 percent of each of the four obligations. A refiner that buys 2025 RINs cheaply can hold them for its 2026 obligation, but it cannot cover more than a fifth of that obligation this way, and anything unused by then is worthless for compliance. That limit is why a RIN price is not a pure long-run asset price: the stock of banked credits can soften a tight year, but only by so much and only for one year.

The other release valve runs in the opposite direction. Under 80.1427(b), an obligated party that falls short in year i may carry the deficit into year i + 1, provided it did not carry a deficit for the same obligation into year i, and it must then meet year i + 1 in full with no deficit carried into year i + 2. A deficit can be deferred once, not rolled forward indefinitely. The deficit itself is the obligation minus the current-year and prior-year RINs applied to it.

Deficits are small against a total obligation in the tens of billions, but they move. The largest in the table is the 1,106 million total renewable fuel RINs carried out of 2023, and it fell to 280 million out of 2024. EPA’s compliance table shows the 2023 deficit as the prior-year deficit added to obligated parties’ 2024 total. A deficit is deferred demand: those parties still have to buy the RINs, one year later, at whatever the price is then. When reading a price series, a year with large carried deficits is a year whose demand partly lands in the next one.

2026 and 2027: a bigger diesel slice

EPA announced the final Set 2 rule on March 27, 2026, and it was published in the Federal Register on April 1, 2026 (91 FR 16388). It sets the 2026 and 2027 standards, reallocates 70 percent of the small refinery exemptions granted for 2023 to 2025 into those two years, removes renewable electricity (eRINs) from the program and partially waives the 2025 cellulosic requirement down to 1.21 billion RINs. It also changes the unit for biomass-based diesel: through 2025 that requirement was set in physical gallons, and from 2026 it is set in RINs like the other three. From January 1, 2027, it also cuts the assigned equivalence value for renewable diesel from 1.7 to 1.5 and sets renewable jet fuel at 1.5 and renewable naphtha at 1.4; EPA expects most renewable diesel to qualify for 1.6 RINs per gallon by application, which still means fewer D4 RINs per physical gallon than in 2026.

The biomass-based diesel percentage rises from 3.15 to 5.24, about two-thirds higher, and the 2025 figure was already expressed in RINs, so the jump is real growth and not a unit change. The check: the 2025 volume of 3.35 billion gallons at 1.6 RINs per gallon is 5.36 billion RINs, and 5.36 divided by the 170.03 billion gallons of gasoline and diesel EPA projected for 2025 is 3.15 percent. The 2026 figure is 9.07 billion RINs.

As an illustration only, holding every RIN at its 2025 average price, the 2026 standards would cost 15.59 cents per gallon of petroleum fuel and the 2027 standards 15.93 cents, against 13.23 cents for 2025. The biomass-based diesel slice alone would rise from 2.99 to 4.98 cents. This is not a forecast. A larger diesel slice raises demand for D4 RINs, and the price that results depends on how much biodiesel and renewable diesel the market supplies.

One proposal did not make it into the final rule. EPA had proposed cutting the RINs generated for imported biofuels and for biofuels made from imported feedstocks. Its fact sheet says it is not finalizing those provisions in Set 2 and intends to finalize them in a future action, beginning in 2028. Until such a rule is published, imported fuel generates RINs at the same equivalence values as domestic fuel.

Data and sources: U.S. EPA, RIN Trades and Price Information (weekly volume-weighted RIN prices and volumes, outlier filters; page last updated October 15, 2026) and RINs Generated Transactions (generation by D-code and RIN year; page last updated October 15, 2026), data retrieved from EPA’s public EMTS dashboard on October 30, 2026. EPA, Annual Compliance Data for Obligated Parties and Renewable Fuel Exporters, Table 1 (exempted gasoline and diesel volumes; page last updated March 27, 2026), retrieved October 30, 2026. EPA, Renewable Fuel Annual Standards (volume requirements, 2015 to 2025) and Overview of the Renewable Fuel Standard Program (GHG thresholds, obligated parties), checked October 30, 2026. EPA, Final Renewable Fuel Standards for 2026 and 2027 and the Set 2 detailed fact sheet (EPA-420-F-26-007, March 2026), checked October 30, 2026. Federal Register, 91 FR 16388 (April 1, 2026), RFS Program: Standards for 2026 and 2027, Partial Waiver of 2025 Cellulosic Biofuel Volume Requirement, and Other Changes, via govinfo, checked October 30, 2026 (implied conventional volume, RIN cost pass-through, E10 statement, percentage standard method). eCFR, 40 CFR 80.1405, 80.1407, 80.1415, 80.1425 and 80.1427, version of October 27, 2026, checked October 30, 2026. Annual price averages, spreads, per-gallon costs, blend positions and the 2026 and 2027 illustration are this page’s arithmetic. No figure on this page is a current RIN price; EPA updates its price series monthly.