Woodpeckers are in the family Picidae. This is a very large family consisting of about 30 genera and 200 species. Picinae is the subfamily of true Woodpeckers with the following Tribes and genera.
Those highlighted in red represent all species on the ComingsBirds.com web pages as well as those form Costa Rica.

Tribe: Dendropicini
Genus: Melanerpes Black creepers (23 species)
 Acorn Woodpecker, Melanerpes formicivorus
 Black-cheeked Woodpecker Melanerpes pucherani
 Gila Woodpecker, Melanerpes uropygialis
 Red-bellied Woodpecker, Melanerpes carolinus
 Red-crowned Woodpecker Melanerpes rubricapillus
Genus: Sphyrapicus - Sapsuckers (4 species)
Genus: Xiphidiopicus - Cuban Woodpecker
Genus: Dendropicos (15 species)
Genus: Mesopicos (3 species)
Genus: Dendrocopos (21 species)
Genus: Picoides
Downy Woodpecker, Picoides pubescens
 Nuttall's Woodpecker, Picoides nuttallii
 Ladder-backed Woodpecker, Picoides scalaris
Genus: Veniliornis (14 species)
Tribe: Malarpicini
Genus: Campethera (12 species)
Genus: Geocolaptes - Ground Woodpecker
Genus: Dinopium - malarpicine flamebacks (4 species)
Genus: Meiglyptes (3 species)
Genus: Hemicircus (2 species; placement in Malarpicini tentative)
Genus: Micropternus - Rufous Woodpecker
Tribe: Picini
Genus: Picus (16 species)
Genus: Mulleripicus (3 species)
Genus: Dryocopus (7 species)
 Lineated Woodpecker Dryocopus lineatus
Genus: Celeus (11 species)
Genus: Piculus (7 species)
Genus: Colaptes - flickers (about 12 species)
 Golden-olive Woodpecker Colaptes rubiginosus
Tribe: Megapicini
Genus: Campephilus (11 species, 2 possibly recently extinct)
 Pale-billed Woodpecker Campephilus guatemalensis
Genus: Chrysocolaptes - megapicine flamebacks (2 species)
Genus: Reinwardtipicus - Orange-backed Woodpecker
Genus: Blythipicus (2 species)
Genus: Gecinulus (2 species)
Genus: Sapheopipo - Okinawa Woodpecker

Photos are presented for those species highlighted in red.