What Is the Arbitrage Rebate Requirement for Tax-Exempt Bonds?

The arbitrage rebate requirement is the rule in section 148(f) of the Internal Revenue Code that requires an issuer of tax-exempt bonds to pay the U.S. Treasury the amount by which the earnings on invested bond proceeds exceed what those proceeds would have earned at the yield of the bonds.

IRS Publication 5271, the IRS overview of the arbitrage requirements (which states it is not formal guidance), frames the rule's place: bonds are tested under both the yield restriction rules of section 148(a) and the rebate rules of section 148(f), and an issue that fails either set is an arbitrage bond.

Both rule sets, and the temporary periods that sit between them, are introduced in the guide to the federal arbitrage rules.

What must be rebated?

The rebate amount is the excess of the future value, as of the computation date, of all receipts on an issue's nonpurpose investments over the future value, as of that date, of all payments on them, with both sides compounded at the bond yield (26 U.S.C. 148(f)(2); Treas. Reg. §1.148-3(b)-(c)).

Treasury Regulation §1.148-3(d)(1)-(2) fills in the two sides of that ledger: payments include amounts paid to buy nonpurpose investments, the value of investments first allocated to the issue, the computation credit and yield reduction payments, while receipts include earnings, return of principal and the value of investments still held at the end of a computation period.

The Form 8038-T instructions warn that "any cash flow representation to the contrary may result in the understatement of rebate amount."

Gains and losses on the disposition of a nonpurpose investment count in the computation as well (26 U.S.C. 148(f)(4)(A)(i)).

The regulation also builds in a computation credit, treated as a payment, taken on the last day of each bond year with rebate-subject gross proceeds and on the final maturity date; the credit was $1,400 for bond years ending in 2007, up from $1,000 before 2007, and it is indexed for bond years ending after 2007, so the $1,400 figure belongs to 2007 bond years and not to later ones (Treas. Reg. §1.148-3(d)(1)(iv), (d)(4)).

Reasonable, direct administrative costs, such as separately stated brokerage or selling commissions, enter the computation as adjustments to payments and receipts, while legal and accounting fees, recordkeeping, custody, overhead and the cost of the rebate computation itself do not (Treas. Reg. §1.148-5(e)).

Costs are generally not reasonable unless they compare to what would be charged on a comparable investment bought with other than bond proceeds.

State law can point to the same destination: New York Local Finance Law §165.00(b) directs that interest and capital gains on invested proceeds go to principal and interest or to the authorized purpose, and, to the extent necessary to maintain the federal tax exemption, be paid to the United States Treasury Department.

The New York statute does not compute the rebate; the amounts and timing come from the federal rules in 26 U.S.C. 148(f) and Treas. Reg. §1.148-3.

Producing the number for a specific issue is the work of the rebate calculation guide.

When are computation dates, and when are installments due?

Rebate is measured as of computation dates, which a fixed-yield issuer may set at any date and a variable-yield issuer must consistently set, after the first required payment date, at either the end of each bond year or the end of each fifth bond year (Treas. Reg. §1.148-3(e)(1)).

The installment schedule runs against those dates: the first rebate installment must relate to a computation date no later than 5 years after the issue date, and each later installment to a date no later than 5 years after the previous one (26 U.S.C. 148(f)(3); Treas. Reg. §1.148-3(f)(1)).

Each installment must be large enough that, added to the future value of previous rebate payments as of the computation date, cumulative payments equal at least 90 percent of the rebate amount as of that date.

Five years is the outside interval rather than a required wait, since a fixed-yield issuer may treat any date as a computation date.

What happens at the final computation?

The final computation date is the date the issue is discharged, and the final payment must bring cumulative payments to 100 percent of the rebate amount, with every rebate payment due no later than 60 days after the computation date it relates to (26 U.S.C. 148(f)(3); Treas. Reg. §1.148-3(f)(2), (g)).

For an issue retired within 3 years, the regulation adds that the final computation date need not fall before 8 months after the issue date and need not fall during a period when a spending exception is expected to apply (Treas. Reg. §1.148-3(e)(2)).

A late or short payment makes the bonds arbitrage bonds unless the failure was not due to willful neglect and the issuer promptly pays a penalty of 50 percent for governmental bonds and qualified 501(c)(3) bonds, or 100 percent for other bonds, plus interest at the section 6621 underpayment rate (26 U.S.C. 148(f)(7); Treas. Reg. §1.148-3(h)).

The penalty is automatically waived when the missed amount plus interest is paid within 180 days after discovery of the failure, unless the Commissioner determines the failure was due to willful neglect or the issue is under examination during the specified window (Treas. Reg. §1.148-3(h); Rev. Proc. 2005-40).

An issuer that overpaid claims a refund on Form 8038-R no later than 2 years after the final computation date, and an overpayment under $5,000 generally cannot be recovered before that date (Treas. Reg. §1.148-3(i)).

On March 12, 2026, Treasury and the IRS proposed regulations that would clarify the time and manner for requesting refunds of rebate overpayments; as of October 2026 the proposal is pending and the existing regulation governs.

Cash awaiting these payments is covered in the rebate fund guide.

How is rebate paid with Form 8038-T?

Issuers pay arbitrage rebate and the related amounts on Form 8038-T, one form per issue, filed with the Internal Revenue Service Center in Ogden, Utah, with a check payable to United States Treasury.

The same form carries yield reduction payments, the penalty in lieu of rebate, the penalty to end that election, and late-payment penalties and interest.

It also collects compliance detail: line 26 asks about qualified administrative costs taken under the GIC and defeasance escrow rules, line 30 asks whether gross proceeds were invested in a GIC, with the provider's name and term, line 31 asks whether proceeds were invested beyond the temporary periods, and line 32 asks who prepared the calculations.

The separate guide to Form 8038-T walks through the filing in detail.

Line 32's question has an institutional backstop: GFOA recommends that issuers adopt formal written post-issuance compliance policies and procedures, and notes that governments may outsource tasks such as arbitrage rebate while keeping ultimate responsibility for seeing the procedures are met.

Which exceptions eliminate the rebate requirement?

Several exceptions treat an issue as meeting the rebate requirement outright or remove a fund's earnings from the computation, and the principal ones key off how quickly proceeds are spent or on the issuer's size.

The small issuer amount rises by the lesser of $10,000,000 or the bonds attributable to public school facility construction, to as much as $15 million, provided no more than $5 million finances non-school purposes (148(f)(4)(D)(vii); Form 8038-T instructions).

The 6-month exception's special definition of gross proceeds excludes amounts in a bona fide debt service fund, amounts in a reasonably required reserve fund, amounts not expected at issuance that arise after 6 months, and certain purpose-investment receipts and grant repayments, and it allows one year for up to 5 percent of the proceeds of certain governmental issues (148(f)(4)(B)(ii); §1.148-7(c)).

Under that exception, earnings on a reasonably required reserve fund remain subject to rebate.

The 18-month exception lives in the regulations rather than the statute, bases the investment earnings counted in gross proceeds for the first two spending periods on issue-date expectations, requires that all gross proceeds qualify for the 3-year capital project temporary period, and is unavailable if any portion of the issue uses the 2-year exception (§1.148-7(d)(1), (3)(ii), (4)).

A construction issue may spend reasonable retainage of up to 5 percent of available construction proceeds within 3 years, and if the 2-year schedule is met, earnings in a bona fide debt service fund are exempt as well (148(f)(4)(C); §1.148-7(e)(2), (h)).

Separately, the issuer of a construction issue may elect on or before the issue date, irrevocably, to pay a penalty in place of rebate on available construction proceeds: 1.5 percent of the underexpended proceeds for each six-month period that misses the 2-year schedule, due within 90 days after each period, filed on Form 8038-T with a separate form for each period, and recorded on Form 8038-G line 40 (148(f)(4)(C)(vii); §1.148-7(k)).

That election can be terminated by paying 3 percent of the unspent proceeds multiplied by the years in the initial temporary period, along with yield restriction and redemption (148(f)(4)(C)(viii); §1.148-7(l)).

Whether to make the irrevocable election is a determination for bond counsel and tax counsel.

The small issuer exception, finally, removes only the rebate obligation: Publication 4079 notes it is not an exception from the arbitrage rules altogether, so the yield restriction rules still apply, a qualifying issuer still needs a temporary period for its project fund, and any reserve fund must be shown to be reasonably required.

The umbrella guide to spending exceptions compares these routes.

Why is positive arbitrage still worth earning?

Section 148(f)(2) defines the rebate amount as the earnings above what the proceeds would have earned at the bond yield, plus income on that excess, so the portion of earnings up to the bond-yield level is not part of the payment.

The mirror image of that comparison is covered in the negative arbitrage guide.

Publication 5271 draws the practical distinction between the two rule sets: the yield restriction rules may let an issuer earn the arbitrage, but the rebate rules may not let it keep the arbitrage.

For eligible investments, §1.148-5(c) provides a yield reduction payment, an amount paid to the United States that is treated as reducing the investment's yield and lets an issuer satisfy yield restriction without restricting the investment's actual rate (Treas. Reg. §1.148-5(c)(1)).

Yield reduction payments are made at the same time and in the same manner as rebate installment payments and are filed on Form 8038-T (Treas. Reg. §1.148-5(c)(2)).

Yield reduction payments are not available for every investment, since the eligible categories are enumerated in §1.148-5(c)(3) and the paragraph generally excludes gross proceeds of advance refunding issues except as expressly provided.

Where the proceeds sit while they wait to be spent is its own question: Virginia's Government Non-Arbitrage Investment Act (Code of Virginia §2.2-4700 and following) lets the state Treasury Board manage and pool authorized investments for bond proceeds, reserves and sinking funds whose earnings are or may be subject to federal rebate, as an additional, alternative method under §2.2-4704 for Virginia localities and authorities.

The IRS asks about the discipline behind this: Form 8038-G line 44 asks the issuer to check a box if it has established written procedures to monitor compliance with the arbitrage, yield restriction and rebate requirements of section 148, and line 43 asks the same about procedures for timely remedial action.

Because the rebate amount is built from an issue's actual receipts and payments, an investment that pays out or draws differently than expected changes the computation, which is where a check of your proceeds against the rules comes in.

mGIC, an independent, SEC-registered municipal advisor and Bidding Agent for bond-proceeds reinvestment that sells no investment product, does not act as principal and is paid by the winning provider rather than the issuer, offers a free, no-obligation reinvestment review or conversation through the contact page.

Which exceptions and computation dates apply to a given issue, and what its filings should say, are determinations for bond counsel and tax counsel.

Last updated 2026-10-06.

This page is general educational information about municipal finance and federal and state rules as of the date shown. It is not legal, tax or investment advice, and it is not a recommendation about any particular investment. Product availability, legality and suitability depend on the issuer, jurisdiction, governing documents and transaction-specific facts. Final legal and tax determinations remain with the issuer's bond counsel, tax counsel and other advisors.