A Washington, DC, Council member who created a plan to provide healthcare to thousands of uninsured residents said he wants to delay it to help the District create a $20 million cash reserve in the face of continued economic uncertainty. David A. Catania, who sponsored the Healthy DC proposal that the council approved last spring, said he will formally ask his colleagues to postpone the program for at least a year. Instead, Catania said the cash reserve is necessary to prepare for a likely continued decline in revenue, which could swell the rolls of residents who seek healthcare under the D.C. Healthcare Alliance, a safety net for low-income residents.