Despite uncertainty and concern buffeting Massachusetts hospitals, the state’s largest health system saw its finances improve last year, turning a small operating surplus and receiving a boon from investment income.

Mass General Brigham on Friday reported a $59.2 million operating gain in the year ending in September, a 0.3% margin, compared to a $45.7 million gain in the same period the year prior. Those numbers, along with a sizable gain from investments, contributed to a $2.4 billion net margin. Last year, the system reported $2 billion in net gains.

The results come after MGB undertook the largest layoff in its history in February, aiming to cut more than $240 million in salary and benefits expense in the face of what executives said were financial pressures. Though expected to save money annually, the reductions cost the system $53 million in the last year.