The best way to check for applied maintenance would be to either run a PTF list via native SMP/E or if you are using CA Chorus Software Manager (CSM) this would list installed maintenance.
The following is sample SMP/E PTF list JCL:
//SMPCSI DD DSN=your.db2tools.CSI,DISP=SHR
//SMPOUT DD SYSOUT=*
//SMPLOG DD SYSOUT=*
//SMPRPT DD SYSOUT=*
//SMPLIST DD SYSOUT=*
//SMPCNTL DD *
SET BOUNDARY ( your target zone ) .