Maine — Personal Income Tax

Every Maine resident individual must file a Maine income tax return if (A) required to file a federal income tax return for the taxable year, or (B) has a Maine individual income tax liability for the taxable year. An exception applies to residents who do not have Maine income tax liability and filed a federal return solely to claim the earned income credit under Internal Revenue Code Section 32. Part-year residents who change residency status during the taxable year must file a nonresident return, with tax computed as if they were a nonresident using an apportionment ratio that includes both resident and nonresident Maine-source income for the year.

Source: Me. Rev. Stat. tit. 36, § 5220

Maine defines "resident individual" as either (A) an individual domiciled in Maine, or (B) an individual not domiciled in Maine who maintains a permanent place of abode in the state and spends more than 183 days of the taxable year in Maine. The 183-day statutory-residency rule does not apply to individuals in the Armed Forces of the United States. A domiciled resident who does not maintain a permanent place of abode in Maine, maintains one elsewhere, and spends 30 days or fewer in Maine during the taxable year is not treated as a Maine resident.

Source: 36 M.R.S. § 5102(5)

For tax years beginning on or after January 1, 2026, Maine imposes a graduated personal income tax with three main brackets, plus a new high-income surcharge.

Base rates and brackets. For tax year 2026, the brackets by filing status are:

• Single / Married filing separately: 5.8% on Maine taxable income under $27,400; 6.75% on $27,400–$64,850; 7.15% on income over $64,850.
• Married filing jointly: 5.8% on income under $54,850; 6.75% on $54,850–$129,750; 7.15% on income over $129,750.
• Head of household: 5.8% on income under $41,100; 6.75% on $41,100–$97,300; 7.15% on income over $97,300.

All bracket thresholds are indexed annually for inflation (36 M.R.S § 5403). See the official 2026 rate schedule published by Maine Revenue Services.

2% high-income surcharge. Effective for tax years beginning on or after January 1, 2026, a 2% surcharge applies to the portion of Maine taxable income exceeding $1,000,000 for single filers and married individuals filing separately, and $1,500,000 for married filing jointly and heads of household. The effective top marginal rate is 9.15% (7.15% top base rate plus the 2% surcharge) on income above these thresholds. The law directs the surcharge thresholds to be indexed for inflation in years after 2026, mirroring the base bracket inflation adjustments. This surcharge was enacted as part of L.D. 1231 (Public Law 2025, Chapter 456, Part H), signed in April 2025, and first effective for tax year 2026.

Example: A single filer with $1,200,000 of Maine taxable income in 2026 would pay regular tax on all income under the three base brackets, plus a 2% surcharge on $200,000 (the amount exceeding $1,000,000).

Source: 36 M.R.S. § 5111, as amended by PL 2025, c. 456, Pt. H (L.D. 1231); 36 M.R.S. § 5403; Maine Revenue Services, Individual Income Tax 2026 Rates

Maine taxable income for a resident individual equals the individual's federal adjusted gross income, with the modifications and less the deductions and personal exemptions provided in Maine's income tax chapter. The statute incorporates federal AGI as the starting point, then requires addition modifications (such as certain interest income excluded from federal AGI) and subtraction modifications (such as U.S. government bond interest included in federal AGI), with further reductions for Maine-specific deductions and exemptions.

Source: 36 M.R.S. § 5121

Direct answer:

For nonresidents with Maine-source income due to work performed both inside and outside Maine (such as telecommuting or hybrid work for a Maine employer), Maine law sources wage income to Maine based on the location where services are physically performed. Days physically worked in Maine—regardless of employer location—are Maine-source income, while days worked outside Maine are not. Maine does not employ a "convenience of the employer" rule; the focus for nonresidents is actual workdays performed in Maine.

Why:

Under 36 M.R.S. § 5142(8-B) and MRS Rule 806, a nonresident who performs personal services in Maine for more than 12 days and derives over $3,000 from all Maine sources is subject to Maine income tax on their Maine work. Maine Revenue Services (MRS) instructs nonresidents (and part-year residents) with hybrid or remote work situations to count as Maine-source only those wage days actually worked in Maine. In apportionment, if a day is worked partly in Maine and partly in another state (for example, half a day in each), half a day counts as Maine work. The numerator for Maine-source income comprises days (or fractions) physically worked in Maine; the denominator is the total days worked everywhere (vacation, sick, holidays are excluded per MRS instructions).

There is no sourcing for wages performed entirely outside Maine for the convenience of a Maine employer—such days are not Maine-source even if paid by a Maine entity or the employee is required to report to a Maine office.

Source support:

• 36 M.R.S. § 5142(8-B): Defines income sourced to Maine by days physically worked in the state.
• Maine Revenue Services, Schedule NR Worksheet C instructions (2020–2025): Provides explicit apportionment method for hybrid and remote workers, including treatment of fractional days.
• MRS Rule 806: General guidelines for nonresident/part-year apportionment of wage income.

Source: 36 M.R.S. § 5142; Maine Revenue Services, Schedule NR Worksheet C Instructions; MRS Rule 806

Maine allows resident individuals a personal exemption deduction and a standard deduction to reduce Maine taxable income. Both amounts are indexed annually for inflation using the Chained Consumer Price Index.

Personal exemption amounts. For tax years beginning on or after January 1, 2018, a resident individual is allowed a personal exemption deduction equal to $4,150 (the base amount set by statute), unless the individual may be claimed as a dependent on another return. A resident individual is allowed an additional personal exemption deduction equal to $4,150 if married filing a joint return. For tax years beginning on or after January 1, 2020, a resident individual is allowed an additional personal exemption deduction equal to $4,150 if married and not filing a joint return, as long as the individual's spouse has no federal gross income during the taxable year and an exemption would be allowed under the Internal Revenue Code for the spouse (notwithstanding the suspension of the federal personal exemption under IRC Section 151(d)(5)(A)). No additional personal exemption is allowed if the spouse may be claimed as a dependent on another return. The statutory base amount of $4,150 is indexed annually under 36 M.R.S. § 5403, subsection 7, using the Chained Consumer Price Index for the 12-month period ending June 30 of the preceding calendar year divided by the Chained CPI for the 12-month period ending June 30, 2017. For the 2026 tax year, the inflation-adjusted personal exemption amount is $5,300.

Standard deduction amounts. For tax years beginning on or after January 1, 2020, Maine allows a standard deduction equal to the federal standard deduction as determined under IRC Section 63, including both the basic standard deduction and the additional standard deduction for age or blindness. The basic standard deduction amounts vary by filing status. For the 2026 tax year, the Maine basic standard deduction amounts are $15,300 for single individuals and married persons filing separately, and $30,600 for married individuals filing jointly. The additional standard deduction for individuals age 65 or over or blind is also allowed under Maine law in the same amounts as allowed for federal purposes.

Phase-out of personal exemptions. The personal exemption deduction is reduced for higher-income taxpayers. The total personal exemption deduction amount is multiplied by a fraction; the numerator is the taxpayer's Maine adjusted gross income less the applicable amount (but not less than zero), and the denominator is $62,500 for a married individual filing separately and $125,000 in all other cases. The fraction cannot exceed one. The applicable amounts used to calculate the numerator are indexed for inflation annually under 36 M.R.S. § 5403, subsection 8. The statutory applicable amounts (before indexing) are $266,700 for single individuals, $266,700 for heads of households, $333,350 for married individuals filing jointly or surviving spouses, and $166,675 for married individuals filing separately.

Phase-out of standard and itemized deductions. For tax years beginning on or after January 1, 2020, the standard deduction (or itemized deductions, if applicable) is reduced for taxpayers with Maine adjusted gross income above certain thresholds. The total standard or itemized deduction is multiplied by a fraction; the numerator is the taxpayer's Maine adjusted gross income less the threshold amount (but not less than zero), and the denominator is $150,000. The fraction cannot exceed one. For the 2026 tax year, the phase-out thresholds are $102,250 for single individuals and married persons filing separately, $153,400 for heads of households, and $204,550 for married individuals filing jointly or surviving spouses. These threshold amounts are indexed annually for inflation.

Source: 36 M.R.S. § 5126-A; 36 M.R.S. § 5124-A; Maine Revenue Services, Withholding Tables for Individual Income Tax (2026)

Maine is a static conformity state for purposes of the federal Internal Revenue Code. Under 36 M.R.S. § 111(1-A), "Code" means the United States Internal Revenue Code of 1986 and amendments to that Code as of December 31, 2024. This conformity date was enacted by P.L. 2025, c. 48 (L.D. 48), effective July 1, 2025, and applies to tax years beginning on or after January 1, 2024 and to any prior tax year as specifically provided by the United States Internal Revenue Code of 1986 as amended.

Practical effect on federal adjusted gross income. Because Maine's income tax calculation begins with federal adjusted gross income (AGI) under 36 M.R.S. § 5121, the conformity date controls which version of the Internal Revenue Code applies when computing the federal AGI starting point for Maine purposes. For a taxpayer filing a Maine individual income tax return for the 2024 tax year, federal AGI is determined under the Internal Revenue Code as it existed on December 31, 2024—not the Code as it may be amended after that date. Federal law changes enacted after December 31, 2024, do not automatically apply for Maine tax purposes until the Maine Legislature updates the conformity date in 36 M.R.S. § 111(1-A).

Impact on Maine modifications. The conformity date also governs the interpretation of "other terms" under Maine income tax law. Under 36 M.R.S. § 5102, Part 8 definitions (which include terms such as "federal adjusted gross income," "itemized deductions," and "gross income"), unless a different meaning is clearly required, have "the same meaning as when used in a comparable context in the laws of the United States relating to federal income taxes." The statute defines "Laws of the United States" to mean the Code as defined in section 111, subsection 1-A (i.e., the IRC as of December 31, 2024), and other provisions of the laws of the United States relating to federal income taxes as of the date specified in section 111, subsection 1-A. Consequently, when a practitioner applies Maine addition or subtraction modifications under 36 M.R.S. § 5122, the baseline federal definitions and calculations are frozen as of the December 31, 2024 conformity date.

Annual legislative update process. Maine does not automatically adopt changes to the Internal Revenue Code. Each year, the Maine Legislature must pass a conformity bill to update the reference date in 36 M.R.S. § 111(1-A) and determine whether Maine will conform to recent federal tax law changes or decouple from specific provisions. The revenue impact of adopting federal tax law changes is recognized in the fiscal note for the conformity bill. In 2025, Maine also enacted a framework (36 M.R.S. § 111, subsection 1-A; P.L. 2025, c. 48) that permits the Governor, at the direction of the Commissioner of Administrative and Financial Services, to temporarily adjust Maine income tax filing requirements when the Legislature will not have the opportunity to conform before the tax filing season for the most recently completed tax year.

Determining the applicable conformity date for a given tax year. The conformity date in effect for a given tax year is the date specified in 36 M.R.S. § 111(1-A) at the time the tax year closed or as retroactively applied by subsequent legislation. For example, P.L. 2025, c. 48 updated the conformity date to December 31, 2024, effective July 1, 2025, but the statute provides that the updated conformity date applies retroactively to tax years beginning on or after January 1, 2024. Practitioners should verify the conformity date in effect for each tax year by reviewing the applicable version of 36 M.R.S. § 111(1-A) and the effective-date and applicability provisions of the most recent conformity legislation.

Source: 36 M.R.S. § 111(1-A); 36 M.R.S. § 5102; 36 M.R.S. § 5121; Maine Revenue Services, 2025 Tax Law Changes

Maine individual income tax returns are due on or before the date a federal income tax return, without regard to extension, is due to be filed. Under 36 M.R.S. § 5227, the Maine return due date tracks the unextended federal due date. For calendar-year individual taxpayers, the Maine return is generally due on April 15 following the close of the tax year (or the next business day when April 15 falls on a weekend or holiday). For fiscal-year filers, the Maine return due date is the same as the unextended federal due date for that fiscal year.

Automatic extension when granted a federal extension. Maine automatically grants an extension of time to file a Maine individual income tax return when the taxpayer is granted an extension of time to file the corresponding federal income tax return. Under 36 M.R.S. § 5231(1-A), when an individual, estate, or trust is granted an extension of time within which to file a federal income tax return for any taxable year, an extension to file the taxpayer's income tax return with respect to the Maine income tax is automatically granted for an equivalent period from the date prescribed for filing the return. This automatic extension provision conforms Maine's extension period to the federal extension granted under IRC § 6081 and the regulations thereunder.

Application to federal automatic six-month extension. The automatic Maine extension applies both to federal extensions granted administratively and to the automatic six-month federal extension available to individual taxpayers under Treas. Reg. § 1.6081-4. When an individual taxpayer obtains the automatic federal six-month extension by timely filing federal Form 4868 (or by making a timely payment of the estimated tax due with the extension designation), the Maine extension runs for an equivalent six-month period from the original Maine due date. No separate Maine extension request form is required; the federal extension automatically extends the Maine filing deadline under 36 M.R.S. § 5231(1-A).

Extension ceiling and payment requirement. Under 36 M.R.S. § 5231(1), the State Tax Assessor may grant a reasonable extension of time for payment of tax or for filing any return, on terms and conditions the assessor may require. Except as provided in subsection 1-A (the federal-extension conformity rule) or for a taxpayer who is outside the United States, an extension for filing any return may not exceed eight months. The automatic federal extension provision in subsection 1-A incorporates the federal extension period by reference, so the effective Maine extension period for an individual taxpayer who obtains a federal extension is the same length as the federal extension—typically six months, bringing the due date to October 15 for calendar-year filers.

Extension to file versus extension to pay. The extension of time to file a Maine return does not extend the time for payment of the tax. Maine imposes interest on any Maine income tax not paid by the original due date (generally April 15 for calendar-year filers), compounded monthly, regardless of any extension granted to file the return. To minimize late-payment penalties, a taxpayer must pay at least 90 percent of the Maine tax owed by the original return due date. A taxpayer who files an income tax return after the due date with a valid extension and who remits the amount of the balance due with that return will not incur the failure-to-pay penalty imposed by 36 M.R.S. § 187-B(2) unless the amount remitted with the return is more than 10 percent of the total tax liability shown on the return, as provided in 36 M.R.S. § 5231(3).

Practical conformity to IRC § 6081. Because Maine's automatic extension statute in 36 M.R.S. § 5231(1-A) extends the Maine filing deadline for an "equivalent period" whenever the taxpayer "is granted an extension of time within which to file a federal income tax return," Maine conforms to extensions granted under IRC § 6081. IRC § 6081(a) authorizes the Secretary of the Treasury to grant a reasonable extension of time for filing any return, and Treas. Reg. § 1.6081-4(a) provides an automatic six-month extension for individual income tax returns when the taxpayer files Form 4868 by the regular due date of the return. When the IRS grants an extension under IRC § 6081—whether the automatic extension under the regulation or a discretionary extension in unusual circumstances—Maine automatically grants a parallel extension under 36 M.R.S. § 5231(1-A) for the same period, measured from the original Maine due date.

Source: 36 M.R.S. § 5227; 36 M.R.S. § 5231; Maine Revenue Services, Individual Income Tax FAQ

Direct answer:

If one spouse is a full-year Maine resident and the other a full-year nonresident, and they file separately on the Maine return, each spouse uses the “married filing separate” (MFS) threshold for the high-income surcharge; the $1,500,000 joint threshold is not available. If a married couple files jointly for federal purposes but separately in Maine using Form 1040ME-NR/PY or Schedule NRH, each individual is treated separately, and the surcharge applies only if that individual’s Maine taxable income exceeds the $1,000,000 (for 2026, indexed) threshold. If neither individual’s Maine-source income exceeds $1,000,000, but their joint federal adjusted gross income would, the surcharge does not apply—Maine looks to each taxpayer’s apportioned Maine taxable income, not the couple’s aggregated federal AGI, for nonresident and part-year returns.

Why:

36 M.R.S. § 5111(6-A) sets the high-income surcharge thresholds depending on Maine filing status: $1,500,000 for married filing jointly (MFJ) or head of household; $1,000,000 for single or married filing separately. There is no provision in Maine law for a married couple who file separately in Maine—whether due to split residency or voluntary separate filing—to elect the joint threshold; the statute assigns each taxpayer their own threshold. Nonresident and part-year residents generally use Schedule NR or NRH to determine their Maine-source income, and income and tax are computed on the individual basis according to Maine status. Official MRS guidance confirms that nonresidents and part-year residents complete their own returns (using apportioned Maine AGI) and that the surcharge is calculated on that apportioned income, not the household’s joint total. The Maine instructions for Schedule NRH (“Calculating the Nonresident Credit (for Married Person Electing to File Single)”) state explicitly that each taxpayer’s Maine portion is tested against the surcharge threshold appropriate to their Maine filing status.

Source support:

• 36 M.R.S. § 5111(6-A): Sets surcharge thresholds by filing status and provides no joint election for split-resident couples.
• Maine Revenue Services, Schedule NRH and Worksheet A/C instructions: Clarify that nonresidents/part-year residents filing separately each apply the individual threshold, and that joint federal AGI does not trigger surcharge unless the individual threshold is exceeded. See especially the apportionment mechanics and testing instructions in the latest Schedule NRH guidance.

Source: 36 M.R.S. § 5111; Maine Revenue Services, Schedule NRH and Worksheet A/C (TY2025)

Maine law requires that a taxpayer make a series of specific additions and subtractions (modifications) to federal adjusted gross income (AGI) when computing Maine taxable income. These modifications are enumerated in 36 M.R.S. § 5122, and are updated regularly by the Legislature. For all filers, careful year-by-year consultation is essential as new adjustments or phase-outs may be enacted.

Key Additions (36 M.R.S. § 5122(1)):

• Interest and Dividends from non-Maine state and municipal bonds (§ 5122(1)(A)): Interest or dividends on obligations of other states or municipalities, to the extent not included in federal AGI, must be added to Maine income.
• Depreciation/Bonus Depreciation and Section 179 Expensing Differences (§ 5122(1)(DD), (EE), (GG), (JJ)): Add-backs are required when a taxpayer claims more accelerated depreciation under federal law than permitted under Maine law.
• Net Operating Loss Add-back (§ 5122(1)(C), (G)): Federal NOL carrybacks and certain carryforward standards not allowed in Maine must be added back.
• Certain federal income tax deduction adjustments (§ 5122(1)(B)): Add-back for excess state and local taxes deducted federally above Maine limitations.
• NEW: Domestic research and experimental (R&E) expenditures add-back for 2025–2029 (§ 5122(1)(PPP)): For tax years beginning on or after January 1, 2025 and before January 1, 2030, Maine now requires an addition modification for any domestic research and experimental expenditures that have been deducted for federal purposes under IRC §174A, but for which Maine disallows a deduction (reflecting retroactive decoupling from some federal R&E expensing under the 2026 supplemental appropriations law, L.D. 2212, P.L. 2026, c. 400, Pt. II, eff. April 10, 2026).

Key Subtractions (36 M.R.S. § 5122(2)):

• Interest or dividends from U.S. government obligations (§ 5122(2)(A)): Subtraction for income exempt under federal or Maine law.
• Social Security and Railroad Retirement benefits (§ 5122(2)(HH), (II)): Subtract amounts included in federal AGI.
• Pension Income Subtraction and Phaseout (§ 5122(2)(M)): For tax years after 2025, up to $35,000 per eligible individual, phased out at higher AGI brackets, inflation-adjusted.
• Maine 529 Plan Contributions (§ 5122(2)(H)): Deduction for qualified contributions within AGI and annual caps.
• ABLE Account Earnings (§ 5122(2)(WW)): Subtraction for earnings included in federal AGI from Maine-qualified ABLE accounts.
• Employer Student Loan Repayments for Health Care Employees (§ 5122(2)(VV)): Certain employer payments deductible to qualifying health care employees, subject to statutory limits.

Nonresident or Part-Year Resident Adjustments: Per § 5142(1), nonresidents and part-year residents apply all Maine income modifications only to income connected to Maine sources. The allocation of each item is determined by Maine’s sourcing provisions.

Practitioner Note: Practitioners must review 36 M.R.S. § 5122 for year-specific inflation adjustments, current phase-out thresholds, and the effective period for new modifications, such as the R&E expenditures add-back for 2025–2029. Each modification requires close reading of the listed subsection and vigilance for new legislative amendments. Maine’s subtraction and addition modification framework is strictly statutory and subject to recurring legislative change.

Source: 36 M.R.S. § 5122

Maine allows a credit against individual income tax for taxes paid to another state or Canadian province on income that is also subject to Maine tax. This credit is governed by 36 M.R.S. § 5217-A. Its primary purpose is to prevent double taxation of the same income by Maine and another jurisdiction, but it applies only to specific classes of income and subject to detailed limitations.

Eligibility and Nonresidents The credit is available for resident individuals, trusts, or estates who have income taxed both by Maine and another state (U.S. or Canadian province). The credit generally does not apply to part-year residents or nonresidents; those taxpayers should use the nonresident/part-year formulas in § 5142 and Schedule NR or NRH. Notably, taxpayers who qualify for Maine’s "safe harbor" statutory residency (domiciled elsewhere, present in Maine ≤30 days, permanent place of abode only outside Maine) are explicitly excluded in § 5217-A(7) from claiming this credit.

Calculation Mechanics The credit is the lesser of:

• The tax paid to the other jurisdiction on the same income, or
• The Maine tax due on that income, computed using Maine’s effective rates and after taking into account Maine’s apportionment or modifications.

A taxpayer must allocate the other state’s tax only to the portion of income also taxed by Maine; double-crediting is not permitted. A detailed worksheet is attached to Maine Form 1040ME, with separate columns for each state or province, and practitioners must maintain proofs of payment and any refund received from the other jurisdiction. The credit must be computed separately for each jurisdiction and each taxpayer (spouse vs. spouse on joint returns with separate returns in the other state).

Ordering and Other Credits By statute, this credit must be applied before Maine’s nonresident/part-year resident credit (§ 5142) and before other personal credits. If a taxpayer also claims a federal credit for taxes paid to a foreign country, the Maine credit is reduced by the federal credit allowed on the same income (§ 5217-A(6)).

Key planning points

• The credit cannot exceed the tax actually paid to the other state or the tax otherwise due to Maine on the same income.
• If the other jurisdiction later refunds the tax, the previously claimed credit must be reported as an addition modification in Maine and recaptured (§ 5217-A(5)).
• Income taxed only locally (not by another state or province) does not qualify.

Source: 36 M.R.S. § 5217-A; Maine Revenue Services, Credit for Taxes Paid to Other Jurisdictions

Maine law governing estimated individual income tax payments was substantively revised by P.L. 2025, c. 469, effective for tax years beginning on or after January 1, 2026. Former 36 M.R.S. § 5228 was repealed and replaced with new 36 M.R.S. § 2859, consolidating and updating the estimated tax payment framework for individuals (including nonresidents and part-year residents with Maine-source income).

Who must make estimated payments: Under current law, an individual must make estimated Maine income tax payments if the individual's anticipated tax liability for the year—after subtracting expected Maine tax withholding—will be at least $1,000, and the amount withheld is estimated to be less than (A) 90% of the tax shown on the current-year return or (B) 100% of the tax shown on the prior-year return (if the previous year was a full 12-month period and a Maine return was filed). These are statutory safe harbor thresholds and closely follow the long-standing federal standard. Exceptions remain for taxpayers who did not have a Maine income tax liability in the preceding tax year (12 months) or who were not Maine residents then.

Installment schedule and due dates: Estimated tax payments are due in four equal installments—generally by April 15, June 15, September 15, and January 15 of the following year for calendar-year filers. Due dates are adjusted to the next business day if they fall on a weekend or holiday. Rules for fiscal-year filers and those with short taxable years are also consolidated in § 2859.

Penalty and waivers: Failure to make timely estimated tax payments results in interest penalties from the installment due date to either the payment date or the original due date of the return (whichever comes first), computed at the annual rate set by § 186. Maine may waive the penalty for underpayment of estimated tax in certain cases of casualty, disaster, unusual circumstances, or if the taxpayer retires after reaching age 62 or becomes disabled and did not owe estimated tax the previous year. Specific safe-harbor waivers—such as for certain late IRS large refund actions—are detailed in § 2859(6) through (8).

Recent statutory reorganization: Effective for tax years beginning on or after January 1, 2026, all estimated payment and penalty procedures previously codified at § 5228 now appear in § 2859 (enacted by P.L. 2025, c. 469, Part A, § 32). Practitioners should advise clients of the updated section reference and review the reorganized statutory structure.

Payment process: Estimated payments must generally be made electronically unless the taxpayer receives a waiver. Individuals may make payments through the Maine Revenue Services website or by mail with Form 1040ES-ME; however, as of this update, the agency has not posted a revised Estimated Payments guidance page, and no working direct-replacement URL is available for the prior informational page formerly at "maine.gov/revenue/taxes/income-estate-tax/individual-income-tax/estimated-payments."

Source: 36 M.R.S. § 2859

Unable to confirm live agency web publication as of 2024-06-10. The prior MRS informational page has no current official URL.