USTC Eligible Securities: Cash & Repo Clearing Scope

Q: Does the SEC rule list which Treasury instruments — bills, notes, bonds, TIPS, FRNs — are clearing-eligible?

No. SEC Rule 17ad-22(a) defines an Eligible Secondary Market Transaction by transaction type and counterparty, not by an enumerated instrument list. It covers a transaction 'of a type accepted for clearing' by the relevant covered clearing agency, which defers the operative instrument-level detail to that CCA's own rulebook.

Q: Are same-day, intraday, or open Treasury cash trades required to clear?

Not currently. Open, intraday, and T+0 same-day cash trades are not presently accepted for clearing by FICC and remain outside the mandate's scope.

Start here

Eligibility is a filter, not a list

It's tempting to look for a table of "eligible Treasury securities" — bills, yes; STRIPS, no; and so on. That table doesn't exist in the rule. SEC Rule 17ad‑22(a) defines an Eligible Secondary Market Transaction (ESMT) as a purchase, sale, repo, or reverse repo in U.S. Treasury securities "of a type accepted for clearing" by a registered covered clearing agency. The instrument itself is almost always a Treasury security in the ordinary sense — the scoping questions that actually decide eligibility sit elsewhere: the transaction structure, its settlement timing, its counterparties, and — for repo — its collateral composition.

The boundary that trips people up

What is (and isn't) a U.S. Treasury security?

Every filter later on this page assumes you're already looking at a U.S. Treasury security. That's a narrower category than "government‑related debt" — and getting this boundary wrong is the single most common mistake newcomers make. Municipal bonds, agency debt, and agency mortgage‑backed securities are not U.S. Treasury securities, no matter how creditworthy or government‑adjacent they are — the clearing mandate simply never reaches them, regardless of who trades them or how.

✓ Issued by the U.S. Treasury — in the universe

Treasury billsShort-term, e.g. 4-week, 13-week, 26-week — sold at a discount, no coupon.
Treasury notes2-, 3-, 5-, 7-, and 10-year maturities, fixed coupon.
Treasury bonds20- and 30-year maturities, fixed coupon.
TIPSTreasury Inflation-Protected Securities — principal adjusts with CPI.
FRNsFloating Rate Notes — coupon resets against 13-week bill auctions.
STRIPS & cash management bills (CMBs)Stripped components of notes/bonds, and short-dated bills issued between regular auctions.

✕ Not issued by the U.S. Treasury — out of scope entirely

Municipal bondsE.g., a city or state general-obligation bond — issued by a state or local government, not the U.S. Treasury.
Agency debtE.g., Fannie Mae or Freddie Mac senior notes, Federal Home Loan Bank bonds — issued by a GSE, not the Treasury.
Agency MBSE.g., Ginnie Mae or Fannie Mae mortgage pools — a different instrument class entirely.
Corporate bondsIssued by a private company, unrelated to the U.S. government.
Foreign sovereign debtE.g., UK Gilts, German Bunds — issued by another country's government.

Why this matters: the clearing mandate's exclusions you'll see below — securities lending, same‑day settlement, mixed collateral — only come into play after you've confirmed the instrument is a U.S. Treasury security in the first place. A municipal bond repo, for example, never reaches those questions at all: it's excluded at the very first step, simply because a municipal bond isn't a Treasury security.

Eligible Securities Map

From the full Treasury universe to what actually clears

Starting from the Treasury universe defined above, two independent filters narrow it further — one path for cash outrights, one for repo & reverse repo.

Each lane below is a four‑gate check, narrowing top‑to‑bottom from the full universe of Treasury securities to the trades a covered clearing agency will actually accept. Scroll the diagram into view and each gate checks off in order, ending in the eligible pool at the bottom — a trade has to clear every gate above it to land there. The exclusions beneath each funnel are the specific carve‑outs confirmed by the SEC or by FICC's published guidance.

Why the middle gate looks different on each side: it isn't a mirrored step — it tests a different dimension in each lane. Cash is scoped by settlement timing (same‑day trades are out); repo is scoped by collateral composition (non‑UST or mixed collateral is out). That's a genuine asymmetry in the mandate itself, not a gap in this diagram — repo carries no separate timing restriction today.

Cash Outrights

✕ Securities lending transactions — SEC‑confirmed as outside the ESMT definition
✕ Open, intraday, and T+0 same‑day trades — not currently accepted for clearing by FICC
✕ Trades where neither counterparty is a CCA direct participant

Repo & Reverse Repo

✕ Repo collateralized by non‑Treasury securities (e.g., Agency MBS) — outside this specific mandate
✕ Mixed‑CUSIP triparty baskets — generally excluded unless UST CUSIPs are present from the outset
✕ Securities lending transactions — SEC‑confirmed as outside the ESMT definition

Illustrative scope map, not a compliance determination tool. Counterparty‑level exemptions (central banks, sovereigns, natural persons, and others) apply on top of this instrument‑ and transaction‑level scope — see the USTC trade flowchart for the full, trade‑level walkthrough.

Interactive tool

Check a trade

Does this instrument and transaction clear?

There's no lookup here for a specific CUSIP or security — and deliberately so. As the funnel above shows, eligibility isn't a property of which Treasury security you hold; it's a property of how the trade is structured. Answer a few quick questions — instrument, transaction type, and collateral — to see whether it clears this page's scope test. Counterparty status is the other half of the determination — the guided walkthrough on the trade flowchart page picks up from here and carries it to a full verdict.

What kind of security is it?

Covers instrument, transaction type, and collateral scope only — it stops short of counterparty status (direct‑participant standing, CCP/DCO and government exemptions, the inter‑affiliate carve‑out), which is what ultimately decides whether a trade that clears this test actually has to be cleared. Continue on the USTC trade flowchart's guided walkthrough for the full node‑by‑node verdict. Illustrative, not a compliance determination.

See it in practice

Six worked examples: does this trade clear?

Each scenario applies the universe boundary and the funnel above to a concrete, realistic trade — three that clear, three that don't, and why.

01Out of universe

A public pension fund buys $10M of a AAA‑rated city general‑obligation bond from a broker‑dealer.

Does not clear

Not a U.S. Treasury security at all — a municipal bond. The mandate never applies, regardless of counterparty or structure.

02Cash outright

An interdealer broker matches a $25M sale of the on‑the‑run 10‑year Treasury note between two registered broker‑dealers, settling T+1.

Clears

Outright purchase/sale, standard T+1 settlement, and a CCA‑accepted instrument type.

03Securities lending

A pension fund lends $15M of Treasury notes to a broker‑dealer under a securities lending agreement, receiving cash collateral.

Does not clear

Structurally a securities loan, not a purchase/sale or repo — excluded from the ESMT definition by its own terms.

04Settlement timing

A money market fund buys a 4‑week Treasury bill from a dealer for T+0 same‑day settlement.

Does not clear (today)

Same‑day (T+0) cash trades aren't currently accepted for clearing by FICC — a timing gap, not an instrument problem.

05Repo, UST from the outset

A hedge fund borrows cash overnight through a triparty repo, posting a basket of Treasury notes selected as collateral from the outset.

Clears

Repo collateralized by UST, with UST CUSIPs present from the outset — not a later substitution.

06Repo, mixed collateral schedule

A money market fund enters a general‑collateral triparty repo whose eligibility schedule allows either Treasuries or Agency MBS; Agency MBS happens to be posted that day.

Does not clear

A basket/GC repo where Treasury is only one of several eligible collateral types — not the specific instrument selected at execution.

Scope, side by side

Cash outrights vs. repo: what narrows each path

Both paths share the same starting universe and end with the same live check — confirming the trade is still on the CCA's current rulebook — but the filter in between is structurally different.

Cash

Outright Purchase / Sale

Narrows on transaction structure and settlement timing

The instrument is a Treasury security either way — what decides eligibility here is how and when the trade settles.

✓ Outright purchase or sale between eligible counterparties
✓ Standard (T+1) settlement cycle
✓ Still listed as accepted in the CCA's current rulebook

✕ Open, intraday, or T+0 same‑day trades
✕ Securities lending transactions

Counterparty‑type exemptions (central bank, sovereign, natural person, etc.) apply on top of this — see the trade flowchart.

Repo

Repo & Reverse Repo

Narrows on collateral composition

The repo itself must be collateralized by U.S. Treasury securities — the collateral mix is where most of the scoping complexity lives.

✓ Repo or reverse repo collateralized by UST
✓ Mixed‑CUSIP triparty basket containing UST from the outset
✓ Still listed as accepted in the CCA's current rulebook

✕ Repo collateralized by non‑Treasury securities (e.g., Agency MBS)
✕ Mixed‑CUSIP baskets where UST enters only as a later substitution
✕ Securities lending transactions

Unlike cash, there's no settlement‑timing carve‑out here — the open question is collateral composition, not timing.

Side-by-side

How the two scoping questions differ

Based on SEC Rule 17ad‑22(a), the SEC's Treasury Clearing FAQ, and published FICC/custodian guidance current as of September 2026.
	Cash Outrights	Repo & Reverse Repo
Governing structure	Purchase or sale	Repo or reverse repo
Primary scoping question	Settlement timing	Collateral composition
Timing‑based exclusion	Open, intraday, T+0 same‑day not currently cleared	Not applicable
Collateral‑based exclusion	Not applicable	Non‑Treasury collateral; late‑entering mixed‑CUSIP baskets
Securities lending	Excluded	Excluded
Final gate	Still listed as accepted in the CCA's current rulebook	Still listed as accepted in the CCA's current rulebook

Key takeaways

What this means for scoping and documentation

Don't build a static list

Instrument type is rarely the blocker

Almost any marketable Treasury security clears these gates. Build your scoping logic around transaction structure and timing, not a fixed security list that will drift out of date.

Repo desks

Flag mixed‑CUSIP baskets early

Triparty repo where UST enters only as a substitution — not from the outset — is generally excluded. This is easy to miss in a collateral schedule review.

Cash desks

Watch settlement tenor, not just counterparty

A trade can clear every counterparty test and still fall outside scope today if it settles open, intraday, or same‑day T+0.

Both desks

Re‑check the CCA's accepted‑type list

The rule defers the operative detail to FICC GSD, CME, and ICE. Their accepted‑for‑clearing product scope can change independent of the SEC rule text.

As of September 2026

Where the scope is still being worked out

SEC

Mixed-CUSIP triparty repo remains an open interpretive question

Industry participants and the SEC continue to work through the applicable scope of the ESMT definition as it pertains to mixed‑CUSIP triparty transactions — baskets composed of both UST and other securities. Published guidance so far indicates such a basket is generally treated as eligible only when UST CUSIPs are present from the outset, rather than added later as a permitted substitution — but firms should confirm current treatment directly with their CCA before relying on it for a collateral schedule design.

Scope Q&A

Questions practitioners ask about eligible securities

Are municipal bonds or agency securities (like Fannie Mae or Freddie Mac debt) covered by the Treasury clearing mandate?

No. The mandate applies only to U.S. Treasury securities — instruments issued by the U.S. Department of the Treasury itself. Municipal bonds, agency debt (e.g., Fannie Mae, Freddie Mac, Federal Home Loan Banks), agency MBS, corporate bonds, and foreign sovereign debt are different asset classes entirely and fall outside its scope regardless of transaction structure, counterparty, or credit quality. See "What is (and isn't) a U.S. Treasury security?" above.

Does the SEC rule list which Treasury instruments — bills, notes, bonds, TIPS, FRNs — are clearing‑eligible?

No. SEC Rule 17ad‑22(a) defines an Eligible Secondary Market Transaction by transaction type and counterparty, not by an enumerated instrument list. It covers a transaction "of a type accepted for clearing" by the relevant covered clearing agency, which defers the operative instrument‑level detail to that CCA's own rulebook.

Are same‑day, intraday, or open Treasury cash trades required to clear?

Not currently. Open, intraday, and T+0 same‑day cash trades are not presently accepted for clearing by FICC and remain outside the mandate's scope.

Does a repo collateralized by Agency securities count toward the Treasury clearing mandate?

No. The mandate covers repo and reverse repo collateralized specifically by U.S. Treasury securities. Repo collateralized by Agency securities or Agency MBS falls outside this particular rule, even where FICC separately clears that activity under other provisions.

Are mixed‑CUSIP triparty repo baskets eligible for Treasury clearing?

Generally not, unless the basket contains U.S. Treasury CUSIPs from the outset rather than as a permitted substitution. This remains an area of active interpretive discussion between the industry and the SEC — see "Where the scope is still being worked out" above.

Are securities lending transactions in Treasuries covered by the mandate?

No. The SEC has confirmed that securities lending transactions do not fall within the definition of an Eligible Secondary Market Transaction, regardless of the instrument involved.

Related USTC pages

Continue on the trade‑level or reference pages

USTC trade flowchart → USTC reference guide →

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