"While any additional income earned from higher yields is taxed at a progressively higher rate, IRMAA applies as a surcharge," he said.
"This means that even $1 of additional income could trigger higher premiums."
With terms ranging from one month to one year, most Treasury bills, known as T-bills, are currently paying well over 5%, as of Dec. 4.
However, T-bills offer a tax benefit over products like high-yield savings, certificates of deposit or money market funds: no state or local taxes on earnings.
T-bill interest is still subject to federal income taxes.
Persons:
Eric Audras, Mullikin, Catherine Valega
Organizations:
PhotoAlto, Getty, Medicare, Green Bee
Locations:
Boston, TreasuryDirect