Ballots are being mailed out this week to West Contra Costa County voters for a May 6 ballot measure designed to keep open Doctors Medical Center and its emergency room.

Measure C would impose a parcel tax of 14 cents a square foot a year on houses, equivalent to $168 a year for a 1,200-square-foot home. It requires two-thirds voter approval to pass.

It would come on top of $99 a year in parcel taxes that property owners in the West Contra Costa Healthcare District currently pay to help fund the hospital, which is located in San Pablo. The health care district covers all of West County.

Registered voters who have not received a ballot by April 15 can call the county elections office at 925-335-7800 to request a replacement ballot.

The ballot must be received in the county elections office by May 6, according to election officials.

Contact Tom Lochner at 510-262-2760. Follow him at twitter.com/tomlochner