A decision by a magistrate to reduce a "wobbler" to a misdemeanor is not subject to appellate review for abuse of discretion.[75]  The defendant, however, may secure appellate review of the denial of a motion to reduce after judgment, under Penal Code § 1237(b), as an order after judgment affecting the substantial rights of the defendant.[76]

[75] People v. Williams (2005), 35 Cal.4th 817, 28 Cal.Rptr.3d 29 (a magistrate's decision, declaring that an alternative felony-misdemeanor ("wobbler") offense charged as a felony is reduced to a misdemeanor, is not appealable).

[76] See People v. Romero (1991) 235 Cal.App.3d 1423, 1425-1426, 1 Cal.Rptr.2d 468 (denial of motion to expunge a conviction under Penal Code § 1203.4 can be reviewed on appeal under Penal Code § 1237(b)); People v. Chandler (1988) 203 Cal.App.3d 782, 787, 250 Cal.Rptr. 730 (same, overruling People v. Soukup (1983) 141 Cal.App.3d 858, 863, 190 Cal.Rptr. 635).

CAL POST CON " VEHICLES " MOTION TO REDUCE FELONY TO MISDEMEANOR " APPELLATE REVIEW OF DENIAL
People v. Feyrer, (2010) 48 Cal.4th 426, 433 n.5 (direct appeal is proper means to review denial of a motion to modify a felony conviction to a misdemeanor, under Penal Code 17(b), for a wobbler offense underlying a plea agreement after termination of probation); see People v. Miller (5th Dist. Jan. 27, 2012) 202 Cal.App.4th 1450, 136, n.4 (direct appeal is proper way to review denial of a motion to vacate plea and modify conviction, on the grounds that a felony conviction for unlawful possession of diazepam, under Health & Safety Code 11350(a) was outside the trial court's subject matter jurisdiction because the offense was defined as a misdemeanor under Health & Safety Code 11375(a), (c)(4)).