Money managers in the municipal market are adding analysts at the slowest pace since before the financial crisis, a sign research staffs are able to manage the volatility stemming from beleaguered Puerto Rico.

AllianceBernstein Holding LP, Nuveen Asset Management, T. Rowe Price Group Inc. and Vanguard Group Inc.—which combined have 59 researchers and oversee about $270 billion in munis—haven’t added analysts in the past year-and-a-half. Neither have banks such as Barclays Plc. Morningstar Inc. in Chicago stopped providing muni research as of June 30.