Moody's Investors Service assigned the "A3" rating to San Francisco-based Dignity Health's $270 million of series 2016A revenue bonds.
The ratings affirmation is based on a variety of factors, including the health system's large size and market share strength.
The ratings agency also affirmed the "A3" rating on Dignity Health's parity debt.
The outlook is stable, reflecting Moody's Investors Service's expectation the health system's operating performance will improve in fiscal year 2017 and that its liquidity and debt measures will strengthen over time.