Supplemental retirement plans offered by local governments have significant gaps, the Center for State and Local Government Excellence reports in a new study.

None of the 457(b) and 401(k) plans at the 20 city and county governments surveyed had automatic enrollment.

Web sites of eight of the 20 failed to tell employees how to enroll in the 457(b) and 401(k) plans, while six lacked comprehensive information on the offerings.

These deficiencies may lead to lower participation rates in these savings vehicles, which are becoming more important to retirement security for public employees as local governments cut back on their traditional retirement plans, the center warned.

The study also noted only four of the 20 cities and counties surveyed by the center had a match for their 457(b) and 401(k) plans.

All state and local governments are allowed to have 457 plans as their primary or supplemental retirement offerings. The Center noted many cities and counties retain legacy 401(k) plans or adopt state-managed 401(k)s.

Fifteen of the 20 government surveyed offer just 457(b) plans as add-ons to their basic retirement coverage.