S&P Global Ratings downgraded Valhalla, N.Y.-based Westchester County Health Care's revenue and refunding bonds to "BBB-" from "BBB."
At the same time S&P downgraded the health system's long-term rating to "BBB-" from "BBB."
The downgrade is a result of the company's weaker than average liquidity relative to similarly rated peers and its weak operating performance.
"While we recognize WCHC has embarked on a growth strategy over the last several years that is strengthening its overall enterprise profile, it has coincided with a period of weaker than expected operating performance and cash flow metrics," said S&P credit analyst Anne Cosgrove.
The outlook is stable, reflecting S&P's expectation that the health system will see an improved operating performance in fiscal year 2018.