Federal Gas Tax History, Adjusted for Inflation

The federal tax on gasoline is 18.4 cents a gallon, and it has been since October 1, 1993, apart from 21 months at 18.3 cents in 1996 and 1997, according to FHWA Table FE-101A (Highway Statistics 2024, dated November 2025). In 2025 dollars the rate set in October 1993 was worth 40.7 cents, so the 18.4 cents of 2025 buys 45 percent of what the same rate bought then (43 percent at September 2026 prices).

FE-101A lists 13 dates on which the gasoline rate changed: 11 increases, counting the first tax in 1932, and 2 cuts. The last increase of more than a tenth of a cent was 4.3 cents under the Omnibus Budget Reconciliation Act of 1993, and no act has changed the rate by more than 0.1 cent in the 33 years since. Section 4081 of the Internal Revenue Code states the rate in fixed cents per gallon with no inflation adjustment, so the erosion is arithmetic: a rate that had kept its October 1993 buying power would be 42.6 cents at September 2026 prices, 2.31 times the rate on the books.

The tax did not peak in 1993. Measured in 2025 dollars, the annual value was highest in 1960, at 43.5 cents from a 4 cent rate, and the six highest years are 1960 to 1965. The 1993 rate rebuilt the value to 40.0 cents in 1994, the seventh highest of the 93 years from 1933 to 2025, and it has fallen in 30 of the 31 years since. Against EIA's annual regular price the tax fell from 17.9% of the pump price in 1998 to 5.9% in 2025.

The statute also carries a date. Section 4081(d)(1) says the gasoline rate shall be 4.3 cents per gallon after September 30, 2028, a date that seven laws since 1998 have moved forward, after the 1993 act first wrote the 4.3 cent provision with a 1999 date. Table 9 lists those laws. The date is a deadline for legislation, not a forecast of the rate.

Every rate change since 1932

FE-101A prints effective dates and rates for each motor fuel but names no acts. Table 1 keeps its gasoline column and attaches the enacting law to each date from the statutes themselves (Statutes at Large and the U.S. Code) and from FHWA's histories. The last three columns convert each rate to constant dollars with the CPI-U of the month it took effect: the 2025 column uses the 2025 annual average (321.943) and the September 2026 column uses the newest index (336.940).

Three steps account for most of the rate: 5 cents in 1983, 5 cents in 1990, 4.3 cents in 1993, together 14.3 of the 18.4 cents. The rest came in half-cent and one-cent steps between 1932 and 1959 and in the 0.1 cent steps of 1987, 1996 and 1997. Most of the early date-and-act pairs line up with the statutes. The National Industrial Recovery Act amended the 1932 act effective "as of the day following the date of the enactment", and FE-101A dates 1.5 cents from June 17, 1933, the day after the June 16 enactment. The Revenue Act of 1940 set up a "Defense Tax for Five Years" whose table moves gasoline from 1 cent to 1½ cents for the period after June 30, 1940 and before July 1, 1945, which matches FE-101A's July 1, 1940 date. The Revenue Act of 1941, in section 521 (defense excise tax rates made permanent which are not increased by that Act), wrote 1½ cents into the gasoline section itself.

Two rows need a note. The return to 1 cent on January 1, 1934 was written into the National Industrial Recovery Act itself. Its section 217 has the President proclaim the date of the earlier of two events, the close of a fiscal year in which receipts exceed expenditures or the repeal of the eighteenth amendment, and provides that effective as of the 1st day of the calendar year following the date so proclaimed, section 617(a) of the Revenue Act of 1932 is amended to read 1 cent in place of 1½ cents. FE-101A's January 1, 1934 date is what that mechanism gives if the proclaimed date fell in 1933; the proclamation itself is not cited here. The Revenue Act of 1934, approved May 10, 1934, then restated the tax in its section 603(b) as "a tax of 1 cent a gallon". The Revenue Act of 1951 was approved October 20, 1951 and raised the rate to 2 cents, with the increase to end on April 1, 1954; FE-101A shows 2 cents from November 1, 1951 and no drop in 1954. FHWA's history explains why: the Excise Tax Reduction Act of 1954 extended the tax to April 1, 1955, the Tax Rate Extension Act of 1955 extended it to April 1, 1956, and the 1956 Act then made 3 cents the rate.

The 1956 and 1959 rows are the highway-funding bargain. FHWA's history describes the 1956 compromise as a gas tax of 3 cents whose revenue, with other highway-user taxes, was credited to a new Highway Trust Fund for the Interstate System and other highway projects, and the 1959 Federal-Aid Highway Act as the first increase after that, to 4 cents on a temporary basis. The Federal-Aid Highway Act of 1961 retained the 4 cents and extended it through September 30, 1972, according to the same history, and the rate then stayed at 4 cents until April 1, 1983, a stretch of 23.5 years that Table 5 measures. Federal tax paid is gallons times the rate, so the gallons burned per licensed driver in each state turn 18.4 cents into dollars per driver.

Where the 18.4 cents goes

The current rate is written in two pieces. Section 4081(a)(2)(A)(i) of the Internal Revenue Code reads "in the case of gasoline other than aviation gasoline, 18.3 cents per gallon," and subparagraph (B) adds: "The rates of tax specified in subparagraph (A) shall each be increased by 0.1 cent per gallon. The increase in tax under this subparagraph shall in this title be referred to as the Leaking Underground Storage Tank Trust Fund financing rate." Eighteen point three plus 0.1 is the 18.4 cents quoted in summaries. The tax is imposed on the removal of taxable fuel from a refinery or terminal, on its entry into the United States, and on certain sales to buyers not registered under section 4101, so it is paid upstream of the pump and arrives at retail inside the price. FE-101A note 2 adds that "Gasoline used by State and local governments and nonprofit educational institutions is not taxed or tax is refunded if paid."

Where the cents are credited has changed more often than the total. Table 2 follows FHWA's Appendix K, which splits each gasoline rate between the Highway Account and Mass Transit Account of the Highway Trust Fund, the LUST Trust Fund, and the General Fund for deficit reduction.

The table shows that a rate and its use are separate questions. From October 1993 the full 18.4 cents was collected, but only 11.5 cents (10 to the Highway Account and 1.5 to Mass Transit) reached the Highway Trust Fund, with 0.1 cent to the LUST fund and 6.8 cents to deficit reduction. On October 1, 1995 the Trust Fund's share rose to 14 cents when 2.5 cents of the deficit-reduction rate moved to it, and on October 1, 1997 the Taxpayer Relief Act of 1997 redirected the remaining 4.3 cents, so that 18.3 cents reach the Trust Fund today: 15.44 to the Highway Account and 2.86 to the Mass Transit Account. FHWA's history describes the 1993 increase as "entirely for deficit reduction, with none credited to the Highway Trust Fund" until 1997.

The most recent year in FHWA's Status of the Highway Trust Fund table (FE-210) shows what the fuel taxes cover. Table 3 takes the fiscal year 2024 Total row.

Motor fuel taxes brought in $34.23 billion against $70.56 billion of spending, 48.5%. The gasoline-and-gasohol line is $24.77 billion, which divided by the 18.3 cents credited to the Trust Fund gives $1.354 billion for each cent of the rate (a division made here, which assumes that FE-210's gasohol column holds all gasoline receipts; the table drops its separate gasoline column after fiscal year 2008, and note 5 says columns were removed "where data is no longer collected"). The gasoline column read $24.46 billion in fiscal 2008, against $24.77 billion in 2024: level in dollars, and about 30 percent lower in constant dollars when each is converted with its calendar year's CPI-U, an approximation for fiscal years. Receipts follow gallons times a fixed number of cents, so the rate's erosion shows up in the Trust Fund as well as at the pump.

Why the rate was 18.3 cents in 1996 and 1997

The 0.1 cent in the 18.4 is a separate levy with its own sunset. FHWA's history dates the LUST rate to the Superfund Amendments and Reauthorization Act of 1986, and the statute as it stood at the end of 1995 said the financing rate "shall not apply after December 31, 1995". It did not apply. From January 1, 1996 the gasoline rate was 18.3 cents and the diesel rate 24.3, in FE-101A. Section 1033 of the Taxpayer Relief Act of 1997 rewrote that sentence to read that the rate "shall apply after September 30, 1997, and before April 1, 2005", and the rate returned to 18.4 cents on October 1, 1997. The span in between was 639 days, or 21 months.

The LUST rate has its own end date in today's statute. Section 4081(d)(3) reads in full: "The Leaking Underground Storage Tank Trust Fund financing rate under subsection (a)(2) shall apply after September 30, 1997, and before October 1, 2028." FE-101A's note 12 records one more gap: collection of the 0.1 cent "was suspended for the period September 1 through December 1, 1990", so the effective gasoline rate was 9.0 cents for those three months. The 1990 annual average in Table 6 and Figure 1 allows for it: 9.500 cents, against 9.525 without the suspension.

The shorthand "18.4 cents since 1993" is therefore right for 31 of the 33 years, and exactly right only since October 1, 1997. The distinction barely changes any dollar figure (0.1 cent on a $1.199 gallon in 1997 is under one-tenth of one percent of the price), but a statement that the rate is "unchanged since 1993" is wrong on the record.

Gasohol paid less until 2005

From 1979 to 2004 the gasoline rate was not what every gallon paid. FE-101A carries a separate column for gasohol, defined in its note 6 as a blend of gasoline and at least 10 percent alcohol by volume, and the lower rate applied to blends such as E10 (the table gives two figures from 1990, one for ethanol blends and one for methanol blends, and Table 4 uses the ethanol figure). The gap was set by statute: the 1998 amendment notes to section 4081 print the earlier alcohol-mixture reduction as "5.4 cents per gallon for 10 percent gasohol". The gasoline-minus-gasohol differences in Table 4 equal 5.4 cents from October 1993 to the end of 2000 and then narrow.

The difference was 5.4 cents from October 1993 until the end of 2000, then 5.3 cents from January 1, 2001 and 5.2 cents from January 1, 2003, and the two rates were equal from January 1, 2005. FHWA's Appendix K, note 4, explains the change: "Effective January 1, 2005, gasohol's partial exemption from the gasoline tax was replaced by an equivalent excise tax credit paid from the General Fund of the Treasury." Appendix K gives no history of the credit, so after 2005 the table records 18.4 cents for gasohol while a credit sits outside it. FE-101A and Appendix K give no share of gallons that were gasohol in any year, so Table 7 applies the gasoline rate to all gallons; for the years before 2005 its tax share is an upper bound on what a gallon of E10 paid.

How long each rate held its value

A cent rate loses buying power for as long as it stays put, and the loss is the ratio of two price levels. Table 5 takes each rate from the month it took effect to the month before the next change, and the current rate from October 1993 to September 2026, the newest CPI-U in the BLS database. It reports how many 2025 cents the rate was worth at each end and the change in buying power between them.

Three rates have lasted more than ten years. The 1.5 cent rate held for 11.3 years and lost 46.6 percent of its buying power through the war and postwar inflation before the 2 cent rate replaced it. The 4 cent rate held for 23.5 years, from October 1, 1959 to April 1, 1983, and lost 70.0 percent: it fell from 43.8 cents in 2025 dollars to 13.2. When the 9 cent rate arrived on April 1, 1983 it was worth 29.4 2025 cents, 2.2 times what the 4 cent rate had fallen to. The rates that came after it lasted from 2.8 to 3.9 years and lost from 7.8 to 16.9 percent before being replaced.

The current stretch is the longest in the record: 33.1 years, against 23.5 for the 4 cent rate. It has lost less, 56.8 percent against 70.0, because prices have risen more slowly. The CPI-U compounded at 5.3 percent a year from October 1959 to March 1983 and 2.6 percent a year from October 1993 to September 2026, so each year at a fixed rate cost less in the later period, and the later period has lasted 9.6 years longer. Whether the present erosion triggers a response is a legislative question the numbers cannot answer; the table shows only that Congress let the 4 cent rate lose 70 percent before the 1982 act, and that the current rate has lost 57 percent.

The tax in constant dollars, 1933 to 2025

Table 1 prices each rate at the moment of its change. Averaging the rate in force over each calendar year and dividing by that year's CPI-U gives a yearly series that can be compared with annual fuel prices. Figure 1 plots the rate as written and in 2025 cents. Because the 1932 tax began on June 21, 1932, the series starts with 1933; the average for a year with a mid-year change weights each rate by the days it was in force, so 1993 mixes 14.1 cents for 273 days with 18.4 cents for 92.

The pattern has four phases. The series starts at 31.7 cents in 1933 and ranges between 19.6 and 32.9 cents from 1941 to 1955, as the 1.5 and 2 cent rates met wartime and postwar inflation. The 3 and 4 cent rates of 1956 to 1959 push it to the 1960 high of 43.5 cents, and 1960 to 1965 are the six highest years of the 93. Inflation then wears the 4 cent rate down to 13.3 cents in 1982. The 1983, 1990 and 1993 increases rebuild it to 40.0 cents in 1994, the seventh highest year in the series.

The fourth phase is the decline since. From 1995 to 2025 the 2025-dollar value fell in 30 of 31 years; 2009, when the CPI-U fell, is the exception. Among the years from 1983 on, the lowest is 2025, at 18.4 cents, and the only years in the whole series with a lower 2025-dollar value than 2025 are 1979 to 1982. These are annual averages of a rate in cents against an index; they say nothing about the cost of building or maintaining roads. For that comparison the gas prices by year, adjusted for inflation page applies the same CPI-U to the pump price, and the diesel price history does so for the 24.4 cent diesel tax's fuel.

The tax as a share of the pump price

A fixed number of cents takes a smaller share of a price that rises. EIA publishes the U.S. average retail price of regular gasoline, all formulations, as an annual series starting in 1992. Table 7 divides each year's average federal rate by that price. The rate column is the day-weighted average from the previous section, so 1993 and 1996 show the mid-year changes.

The share was 17.1% in 1994, the first full year at 18.4 cents, and peaked at 17.9% in 1998, when regular averaged $1.030. It was above 15 percent only from 1994 to 1999. It has been below 10 percent in every year from 2004 to 2025, 22 years in a row, with a low of 4.7% in 2022 when regular averaged $3.951. In 2025 it was 5.9% on a $3.097 price. The share moves with the price year to year (it rose from 5.7% in 2008 to 7.8% in 2009 as the price fell from $3.246 to $2.353), while the steady downward drift under that movement is inflation.

The two forces can be separated. Between 1994 and 2025 the average regular price rose 2.88 times, from $1.075 to $3.097, while the CPI-U rose 2.17 times. In 2025 dollars the 1994 price was $2.335, against $3.097 in 2025, so the price itself rose in real terms and the frozen tax lost ground on both counts. Had the price only kept pace with the CPI, 18.4 cents on a $2.335 price would still be 7.9%. State taxes sit on top of the federal tax and are not part of any figure here: the state-by-state tax table and the breakdown of a gallon's price show where the federal slice sits among the others, and why California gas is so expensive covers one state's fuel taxes in detail.

What indexing would have produced

One way to size the erosion is to ask what each past rate would be at current prices. The arithmetic is a restatement of Table 1: take the cents set at a date, multiply by the CPI-U now and divide by the CPI-U then. Table 8 does it for the rates set since 1951, using September 2026 as the endpoint. It is a conversion of past rates to current prices, not a proposal or a forecast of any rate.

Restated this way, the October 1993 rate is 42.6 cents, 2.31 times 18.4. The rate set in October 1959, the high of the annual series, would be 45.8 cents, and the 9 cents of April 1983, the first increase after the 23.5-year plateau, would be 30.8. Every row in the table exceeds 18.4 cents. The 18.4 cents of October 1997 is 38.4 cents in September 2026 prices, so the rate has lost about 52 percent since the last time it changed.

Revenue arithmetic follows from Table 3 only with a constant: at $1.354 billion per cent, 24.2 extra cents on the 18.4 would be about $33 billion a year if gallons were unchanged. That holds gallons at their fiscal 2024 level and ignores how demand responds to price; it is shown only to size the gap between the rate on the books and the rate that kept its 1993 value. The statute supplies the other half of the picture: the rate is a number of cents written into section 4081, so each change in Table 1 is a change to that text.

The 2028 date and its extensions

Section 4081(d)(1) of the Internal Revenue Code reads in full: "The rates of tax specified in clauses (i) and (iii) of subsection (a)(2)(A) shall be 4.3 cents per gallon after September 30, 2028." Clause (i) is the gasoline rate and clause (iii) the diesel and kerosene rate. FE-101A shows the same date in its last row, "Termination (21) October 1, 2028", and its note 21 says "Taxes terminate on the date shown except for 4.3 cents per gallon which will continue indefinately" [sic]. Taken together with the end of the 0.1 cent LUST rate under subsection (d)(3), the text puts the gasoline rate at 4.3 cents from October 1, 2028 unless Congress changes the date. The text of the U.S. Code as published by the Office of the Law Revision Counsel is current through Public Law 119-136 (October 22, 2026) and shows no change to that date.

The date has moved many times, and Table 9 separates two provisions. Until 1993, subsection (d)(1) ended the Highway Trust Fund financing rate: the 1990 budget act moved that date from 1993 to 1995 and the 1991 surface transportation act from 1995 to 1999. The notes describe the 1993 budget act as amending the section generally, substituting "provisions decreasing tax rate imposed on taxable fuels to 4.3 cents per gallon beginning on and after Oct. 1, 1999, for provisions terminating the Highway Trust Fund financing and deficit reduction rates on and after Oct. 1, 1999, and Oct. 1, 1995, respectively". That is the 4.3 cent provision, and its date has been changed by seven laws since: TEA-21 (2005), SAFETEA-LU (2011), MAP-21 (2016), the FAST Act (2022) and the Infrastructure Investment and Jobs Act (2028), plus two stopgaps, P.L. 112-30 and P.L. 112-102, that moved it by months in 2011 and 2012. Each of the seven was signed before the date it replaced, except that P.L. 112-141 came on July 6, 2012, the date a one-week stopgap in P.L. 112-140 (signed June 29, 2012) had set.

The table is a history of deadlines, and a deadline in the statute is not a forecast. Within the 4.3 cent provision the date moved later each time: by six years in 1998, 2005, 2015 and 2021, by 4.25 years in 2012 (June 30, 2012 to September 30, 2016) and by months in the 2011 and 2012 stopgaps. That record says nothing about 2028, which depends on legislation not yet written. Table 9 starts in 1990. Earlier notes show the financing-rate date moving under the section's previous numbering (the 1987 note for subsection (e)(1) substitutes 1993 for 1988) and are left out.

Choosing the CPI base year

Every constant-dollar figure here is one CPI-U ratio: the tax in cents, times the base index, divided by the index of the date. Two bases are shown because the other price-history pages on this site use different ones. The diesel price history uses the 2025 annual average (321.943), and the gas prices by year page uses September 2026 (336.940). Moving from one to the other multiplies every real value by 1.0466, so the ordering of the years never changes; on this page the 2025 column leads and the September 2026 column sits beside it.

The worked case is the October 1959 rate. The CPI-U was 29.4, so 4 cents is 4 x 321.943 / 29.4 = 43.8 cents in 2025 dollars, or 45.8 cents at September 2026 prices. The index is the BLS Consumer Price Index for All Urban Consumers, all items, U.S. city average, not seasonally adjusted, 1982-84 = 100, from the BLS public API. The 2025 annual average is the mean of 11 monthly values, because BLS marks October 2025 as unavailable following the 2025 lapse in appropriations. Annual averages are calculated as the mean of the monthly values, and the 48 annual values from 1978 to 2025 match the CPI column of the gas price history. A CPI-U is an average basket, not the price of road construction or of gasoline, so these figures describe the purchasing power of the cents and nothing about what the tax pays for. The PetroEyes gas price page carries the current city prices that sit on top of the tax.

Sources and check dates

Data and sources, all checked November 4, 2026: Federal Highway Administration, Highway Statistics 2024, Table FE-101A (Federal Tax Rates on Motor Fuels and Lubricating Oil, dated November 2025; the 2023 edition, dated October 2024, prints the same gasoline column, and Highway Statistics 2024 is the latest edition on FHWA's index) and Table FE-210 (Status of the Highway Trust Fund, updated October 2025). FHWA, Funding Federal-aid Highways, chapter 7 and Appendix K (FHWA-PL-17-011, January 2017; the FHWA publications index lists no later edition), and the Highway History page When did the Federal Government begin collecting the gas tax? (updated June 27, 2017). Statute: 26 U.S.C. 4081 (text current through Public Law 119-136, October 22, 2026). Acts as enacted, from the Statutes at Large on govinfo.gov: National Industrial Recovery Act (48 Stat. 195), Revenue Act of 1934 (48 Stat. 680), Revenue Act of 1940 (54 Stat. 516), Revenue Act of 1941 (55 Stat. 687), Revenue Act of 1951 (65 Stat. 452), Surface Transportation Assistance Act of 1982 (96 Stat. 2097), Omnibus Budget Reconciliation Act of 1990 (104 Stat. 1388), Omnibus Budget Reconciliation Act of 1993 (107 Stat. 312), Taxpayer Relief Act of 1997 (Pub. L. 105-34), Intermodal Surface Transportation Efficiency Act of 1991 (105 Stat. 1914), Pub. L. 105-178, Pub. L. 109-59, Pub. L. 112-141, Pub. L. 114-94 and Pub. L. 117-58. Bureau of Labor Statistics, CPI-U, all items, U.S. city average (CUUR0000SA0), monthly values through September 2026. U.S. Energy Information Administration, U.S. Regular All Formulations Retail Gasoline Prices, annual (release of November 3, 2026). Aviation gasoline, special fuels and the 1932 act text itself are not tabulated or quoted; state gasoline taxes are not in any table. Rates before 1956 follow FE-101A and the cited acts; all constant-dollar values, shares and sums are calculated from those inputs.