To combat rising interest rates set by the market on long-term bonds, the Treasury is increasing its issuance of short-term bills. This moves the debt under the Federal Reserve's direct influence, allowing for potential rate manipulation to manage costs.

A powerful but subtle form of Fed-Treasury coordination exists. The Fed could alter its portfolio rollover strategy, reinvesting its maturing bonds into T-bills instead of across the curve. This would provide the Treasury with short-term funding while normalizing the Fed's balance sheet, all without disrupting public markets.

A proposed plan to shift the Fed’s holdings to short-term T-bills forces the government to refinance its massive debt stack every year at prevailing market rates. This creates enormous risk, making the U.S. government's financial position resemble a homeowner with a giant adjustable-rate mortgage, vulnerable to catastrophic payment shocks if rates rise.

New Fed Chair Kevin Warsh has a path to reduce the Fed's balance sheet beyond direct asset sales (QT). By working with the Treasury to reform bank liquidity requirements, such as the supplementary leverage ratio, banks would need to hold fewer reserves. This naturally shrinks the Fed's liabilities and overall balance sheet size.

While shrinking the Fed's balance sheet is effectively off the table, a significant internal debate focuses on its composition. The key question is whether the Fed should hold assets proportional to Treasury issuance or shift to mostly short-term bills to insulate its profits from political scrutiny.

While the market fixates on rate cuts, the Fed's decision to reinvest mortgage-backed security proceeds only into T-bills adds significant duration risk to the market monthly. This is a subtle but impactful form of hawkish policy that counteracts easing narratives.

The Fed's plan to reinvest maturing mortgage-backed securities (MBS) into Treasury bills is a stealth liquidity injection. The US Treasury can amplify this effect by shifting issuance from long-term bonds to short-term bills, which the Fed then absorbs. This is a backdoor way to manage rates without formal QE.

The Fed plans to align its balance sheet duration with the Treasury's by reducing its holdings of long-term bonds. This would steepen the yield curve by raising long-term rates (hurting mega-caps) while simultaneously cutting the Fed Funds rate to ease pressure on smaller businesses with floating-rate debt.

Despite the Federal Reserve's plan to purchase $490 billion in T-bills in 2026, easing immediate funding pressure, the U.S. Treasury is expected to increase coupon auction sizes in November. This preemptive move aims to mitigate the long-term risks associated with a rising T-bill share of debt, such as financing cost volatility.