The federal government posted a $3.9 billion deficit in the first two months of the fiscal year.
The result for the April-to-May period compared to a $1.5 billion surplus for the same stretch last year.
Revenues increased $6.5 billion, or 8.9%, largely due to higher tax revenues.
The Finance Department says program expenses excluding net actuarial losses rose $10 billion, or 15.9%.
Public debt charges increased $2.3 billion, or 33.8%, due to higher interest rates.
Net actuarial losses fell $0.4 billion, or 23.2%.